...telescope mirrors tend to be large units and not individual sections.
Increasingly large modern telescopes tend to be large units of individual hexagonal mirrors. They are less expensive to make, take less time to make, are less complicated in grinding, polishing, figuring, spinning, have less physical challenges to move, transport, ship, many companies can work on the multiplicity of optics at the same time, and the casting of many smaller mirrors offer many solutions that one big mirror cannot solve. Some considerations are weight, mounting, manufacturing, cost, supply time, thermal qualities, stress, flexure, etc.
Increasingly large modern telescopes tend to be large units of individual hexagonal mirrors....
True. But I don't know of anyone who's made a large telescope from a multitude of lenses. I'm sure it's not impossible, but I'm guessing it's much harder to perform adaptive optics with lenses (vs. mirrors). I think the key to the success of MMTs was they developed not only computer control of the mirror surfaces but also a way of making larger mirrors using some kind of spin casting at about the same historical time.
I don't know - but just piling up lots of little light buckets probably does not give you the results you're seeking.
One of the results we're looking for is the addition of multiple smaller primary objectives to create a larger telescope which functions like a much larger single mirror which would meet project objectives.
The multiple lens project MLT and the ULT MMT mirror-based project are two different projects. The MLT won't be upscaled beyond the largest refracting elements that I have access to which is around 5 to 10 inches.
There is another lensing project that may use lenses 50 to 100-inches in diameter, larger than the Yerkes 40-inch refractor, but I don't see putting together a multiple lens MLT using these. As expected, the weight, around 500 to 1000 pounds will be a limiting factor.
Facilities to spin cast a thousand inch mirror would be prohibitively expensive and challenging, and some will say a single mirror of that size will fail, but consider that I can more likely handle ten 100 inch mirrors. At some point size won't matter because the project will become prohibitively expensive.
Fly Eye Telescope A million inch diameter refractor for space applications?
A new type of telescope is currently being considered by the Big Brain is one that uses many small polymer lenses to make one giant telescope objective. The small lenses could easily number into the thousands with production techniques. These lenses in theory could produce an image of clarity rivaling large whole mirrors. Somewhat similar to the eye of a fly, the many elements would be contained within the outlined shape of a much larger objective. How big? A thousand 1-inch lenses will make the equivalent of a 1,000 inch lens.
Apps for the Fly Eye Telescope would serve space. Taken up over several rocket flights, millions of Fly Eye lenses could be assembled into a million inch telescope. The lenses weigh almost nothing, and thermosetting resins are already well researched and developed for applications in space.
Going with large refractive optics poses a problem because the very weight of a single large lens starts to distort it. On the other hand, mirrors can be cradled somewhat and the stress on them is not so unmanageable.
It looks like astronomers increased the size of refractors up to 40-inches. An article in SKy & Telescope talked about some of the challenges faced with the weight of this large objective. I don't know of any very large multiple primary lens refractor telescopes. However, for the amateur scientist exploring the uniqueness of a small refractor multiple lens telescope, the mounting of the individual elements is not a weight problem and the project can serve a very useful purpose. The max diameter refracting lenses I have access to are all relatively light in weight. On the other hand, the largest single element refractor in the world is the 40 inch Yerkes Observatory telescope. The objective lens weighs 225 Kg.
The flip side of this is that as the materials change from glass to polymer materials, the weight reduces and the 40 inch barrier will no longer apply.
Glass Multiple Lens Telescope Results of MLT Experiments
The first night out with the Multiple Lens Telescope produced this first image
____________________
Experiments went well with the "conventional lensing" to temporarily rig a multiple lens telescope. The importance of this was to test optical quality and the effects of lensing additives. A multiple lens telescope has the benefits same as adding mirrors together in MMT configurations. The conclusion of this experiment indicates the lenses can follow a curved substrate with one central focal point. The mount of these particular discrete elements will become a focus in the future. Will each simple attach to the substrate or will they use an alt-azimuth micro-mount? More tests and experiments will follow.
The Walking Telescope - Determining Walk distance Which servo to use - standard or continuous rotation?
One element to examine in the case of the Walking Telescope is the distance the "cage" must walk. Standard servos that provide the motion can move through approximately 270 degrees. Gearing this from the feed horn can be an effective and low cost, Propeller driven, method to gain the telescoping drive.
But exactly how far must the secondary walk? First we need to consider the transforming and morphing application set forth by the VARFL and the Intelligent Glass.
This leads to the Intelligent Telescope which will have a number of configurations stored in the Propeller chip(s). Take a 6.375simple example. Convert and morph from a RFT telescope to a Schmidt camera (lenseless design). Our telescope is a 4.25 inch, the RFT is F3 and the Schmidt Camera is F1.5.
First we need to know the FL of the primary in each instant. The RFT is 12.75 inches and the Schmidt Camera is 6.375 inches. The difference is 6.375 inches. The telescope must walk this distance to properly transform.
However, more extreme cases exist. Take for example the LFT telescope at FL=60 inches at F10 and the Dobsonian at f4. The dob has a focal length of 24-inches. To transform from the LFT into the Dob requires a walk distance of 36 inches which is 3-feet or a full yard long!
A standard servo will not accommodate most transforming configurations. A continuous rotation servo may benefit this arrangement but it will need an encoder to count and track focal length position. Another possibility is a stepper motor but we are committed to using servos at this time.
First Light: This is the first setup of the MLT Multiple Lens Telescope
for optical testing.
The round image at left is the Full Moon as imaged through the MLT for
the first time. Note the clarity and sharpness of the globe and the uniform
proportions.
Spectacular Performance Images from the MLT
Multiple Lens Telescope
We can't help but be excited about the first performance images returned from the MLT Multiple Lens Telescope. These large refracting elements were set up to image the Moon, as seen between the crack of two tall skyscrapers during the weekend.
Equipment was set on top of a designer sidewalk block. The image of the Moon was cast onto a sheet of 8 1/2 x 11-inch paper and photo'd with a SONY Cybershot.
The interesting part about this experiment was the number of people passing by who were interested in what I was doing.
The refractor lens has a smooth exceptional figure as seen in
the light of the Moon
Attestation to the fine quality of the refracting elements
in the MLT, this lunar image shows three sharp vicinity
stars in the same field of view. Exposure is less than 1
second.
Not easy to locate - The Moon was found in the crack between two
skyscrapers after walking several city blocks in the Capitol City of Taipei. The brightest image in the lens is the Moon.
The Secret of the MLT Multiple Lens Telescope Revealing, for the first time, the key to making a successful MLT telescope
What is the key to successfully building the MLT Multiple Lens Telescope?
The secret is in holding and adjusting multiple refractor lenses. But the question is how to hold and focus the image of two lenses at the same time?
The key to making a successful MLT is contained in two boxes. Each box contains a 3.5-inch diameter double convex refracting glass element, an objective mount, and "Helping Hands."
Helping Hands hold the lenses and position and reposition the lens in any direction
Nearly every electronics enthusiast is familiar with the proverbial helping hands that can hold a printed circuit board and position it with a magnifying glass held above the work material for closeup viewing.
Two Helping Hands kits were purchased at the electronic parts store. This is model SN-392 from Pro's Kit. The cost is US$10 each. The reason the SN-392 works so well is for a couple of reasons. First, the magnifying element is pure glass and finely figured, and produces great images. Second, from one box tested to the next, the focal length of multiple refracting lenses are identical!
Specifications - 1st MLT Multiple Lens Telescope
Diameter of each lens - 3.5 inches
Number of lenses - two
Resolving power - equal to a 7-inch refractor
Light gathering power - equal to a 5-inch
Type of lenses - double convex
Project cost - $20
Mounting Type - helping hands
Test subject - the Moon
Telescope Systems Design Program TSDP
Running part 3 of the Telescope Systems design program gives the information for MLT mode. Though designed for multiple mirrors, the program works just as well with multiple refractor lenses. Here we can see that two 3.5 inch lenses can be equal in resolution to a 7 inch refractor and in light gathering power to a 5 inch refractor.
[SIZE=1]TELESCOPE SYSTEMS DESIGN PROGRAM - FILE: TELESCOPE3.BAS
MMT MULTIPLE MIRROR EQUIVALENT DETERMINATOR
DIAMETER OF MIRROR IN INCHES? 3.5
NUMBER OF MIRRORS? 2
AREA OF 1 MIRROR = 9.61625
AREA OF 2 MIRRORS 19.2325
RESOLUTION MIRROR SIZE (INCHES) = 7
LIGHT GATHERING MIRROR SIZE (INCHES) = 4.949747
AGAIN? 1=YES 2=NO 2
BYE[/SIZE]>
Adding More Elements to a MLT Multiple Lens Telescope The results are surprising!
How can relatively tiny lenses that are only 3 and a half inches in diameter end up equaling a 70-inch diameter telescope? The largest refracting telescope in the world is only 40-inches in diameter..
At a cost of ten dollars per element, it would be reasonable to create a hundred or two hundred dollar telescope. Let's take a look at the results of the design.
For 10 lenses ($100)
* Equal to a 35-inch diameter telescope in resolving power
* Equal to a 11-inch diameter telescope in light gathering power
For 20 lenses ($200)
* Equal to a 70-inch diameter telescope in resolving power
* Equal to a 16-inch diameter telescope in light gathering power
Mirrors by Comparison - a Cost Analysis
If you did this telescope project with a single 70-inch mirror, it could cost several million dollars. If one considers the cost of a 16-inch mirror, the cost can easily range into $2,000.000 or more. That does not include the parts required to build the massive telescope. The cost quoted to build the MLT includes the mount.
The results are remarkable. By putting together 10 or 20 lenses, up to a 70-inch telescope can be created! Here's the tech info we need - run part 3 of the TSDP code and extract the data.
[SIZE=1]TELESCOPE SYSTEMS DESIGN PROGRAM - FILE: TELESCOPE3.BAS
MMT MULTIPLE MIRROR EQUIVALENT DETERMINATOR
DIAMETER OF MIRROR IN INCHES? 3.5
NUMBER OF MIRRORS? 10
AREA OF 1 MIRROR = 9.61625
AREA OF 10 MIRRORS 96.1625
RESOLUTION MIRROR SIZE (INCHES) = 35
LIGHT GATHERING MIRROR SIZE (INCHES) = 11.067972
AGAIN? 1=YES 2=NO 1
DIAMETER OF MIRROR IN INCHES? 3.5
NUMBER OF MIRRORS? 20
AREA OF 1 MIRROR = 9.61625
AREA OF 20 MIRRORS 192.325
RESOLUTION MIRROR SIZE (INCHES) = 70
LIGHT GATHERING MIRROR SIZE (INCHES) = 15.652476
AGAIN? 1=YES 2=NO[/SIZE]
Adaptive optics is a way of distorting mirrors to adjust for atmospheric effects but those mirrors are still single surfaces.
Today there are numerous AO designs, some of which are of great complexity. In the simplest use form, one can buy an off the shelf AO unit and connect it to the eyepiece and start observing. I should clarify that my work in the 1970s was the development of active optics systems that flex and control the entire primary mirror. Although the mirror is a single surface, its figure is shaped and modified by robot with 144 active locations or zonal figure points. For the modern version, see the post for Intelligent Glass.
Thanks for the good suggestion - it looks like a very interesting book and could be very useful for lots of info including the ray tracing software. That's also a good link - I have half of the books listed and plan to obtain the remainder.
As of interest, I see a book listed there about making a doublet lens, by Norman Remer. It talks about a 6-inch refractor, though the process would apply to larger lenses. I had a 40-inch lens a few years ago that would have made a nice refractor telescope, in a tie with the world's largest at Yerkes Observatory, but as mentioned, the weight and flex correction would make one big and massive telescope bigger than Lick Observatory!
A multiple-objective scheme like Humanoido proposes will work in only two circumstances:
1. The images formed are erect (i.e. not inverted), and the subject distance and focal distance are the same (i.e. magnification is 1:1). This is unlikely in an astronomical app.
2. The lenses surrounding the central lens form their images off-axis, in the same way that pieces of a Fresnel lens would. This almost certainly precludes cheap lenses.
That book recommendation makes me think of a recommendation - keep your books located high up. My main library was 40-feet long and located up in the observatory above my garage and everything was always safe and "high and dry." But when I moved the library to a lower level, the entire city was flooded in the Spring season and I lost half my books. Many of those were astronomy books. This makes a good opportunity to rebuild the library at the new observatory and get lots of new books at the same time. As another recommendation, if you think your eyesight is getting too old for adding books to your reading library, email me and I'll tell you about a new noninvasive treatment that will make you think you're 20 again.
Lambda Research has a freebie version of their OSLO optical software that's fun to play with, probably good enough for getting some feeling for how resolution, chromatic aberration, etc. is affected by lens configurations, etc. They have a pdf manual that's free to download.
For those who wish to learn astronomical information about the working validity of multiple objective mechanics and concepts that have remained in successful use for decades and led to numerous astronomical discoveries and new data, I would suggest a referral to the SPIES technical documents library on the construction and design for MMTs which contain information that can be scaled up or down and simplified for working amateur applications at low cost.
Lambda Research has a freebie version of their OSLO optical software that's fun to play with, probably good enough for getting some feeling for how resolution, chromatic aberration, etc. is affected by lens configurations, etc. They have a pdf manual that's free to download. Just a thought: http://lambdares.com/education/oslo_edu
You're a gold mine of information! Thanks again - I may need to get a pc to supplement the mac but first I'll do some research on ray tracing at the Astrophysics Dept. where they're heavy into macs... Actually where OSLO says working with 10 surfaces would be a restriction, it's not. Consider working with eight 72 inch objectives. In terms of size, reaching the goal of a 200 inch mirror would be satisfied for the ULT project with 8 surfaces as it would equal a 204 inch mirror for light gathering.
[SIZE=1]TELESCOPE SYSTEMS DESIGN PROGRAM - FILE: TELESCOPE3.BAS
MMT MULTIPLE MIRROR EQUIVALENT DETERMINATOR
DIAMETER OF MIRROR IN INCHES? 72
NUMBER OF MIRRORS? 8
AREA OF 1 MIRROR = 4069.44
AREA OF 8 MIRRORS 32555.52
RESOLUTION MIRROR SIZE (INCHES) = 576
LIGHT GATHERING MIRROR SIZE (INCHES) = 203.646753
AGAIN? 1=YES 2=NO 2
BYE[/SIZE]
The Big Brain worked with a Fresnel lens to enlarge the TV screen and this type of lens introduces so much distortion that it was found to be totally unusable. There's a man who produces very large and so called accurate Fresnel lenses and I contacted him. He tells me several people considered his lenses for astronomical use but as far as success, he never heard back from anyone. Nor can he quote any optical specifications for the lenses, which makes any apps for it mute.
http://en.wikipedia.org/wiki/Fresnel_lens A Fresnel lens (/freɪˈnɛl/fray-nel) is a type of lens originally developed by FrenchphysicistAugustin-Jean Fresnel for lighthouses. The design allows the construction of lenses of large aperture and short focal length without the mass and volume of material that would be required by a lens of conventional design. Compared to conventional bulky lenses, the Fresnel lens is much thinner, larger, and flatter, and captures more oblique light from a light source, thus allowing lighthouses to be visible over much greater distances.
However, although one may consider a Fresnel to be a cheap lens, there are other cheap lenses from a money viewpoint that are mass produced and perform quite well in forming good images. In the future, we will look at using some of these lenses. Overseas, I may have a source for tens of thousands of these lenses so it would be advantageous to do experimenting with some in multiple configs. and come up with some giant fun-for-experimenting Fly Eye multiple lensing telescopes.
Build a James Web Space Telescope or ULT Models have working mirrors that measure reflectivity using sunlight
Optical Telescope? The Webb is designed as an Infrared Telescope beyond the optical vision of humans. Not all telescopes operate in optical ranges. The Big Brain, although has announced the ULT Project, Ultra Large Telescope, has not announced the design or the wavelength of operation.
When does a mirror have six sides?
The illustration shows one of two methods of building a multiple
mirror telescope MMT. This method has no mirror in the center to
facilitate design.
A gold mirror - JWST completes the gold coating of it's telescope
mirrors with segment C1. A microscopically thin layer of gold
maximizes the reflectivity of these mirrors to infrared light.
The ULT Project is fully capable of producing gold cast coated
polymer iGlass mirrors. The expense on a gold mirror is greater.
__________________________
Webb will have a large mirror, 6.5 meters (21.3 feet) in diameter and a sunshield the size of a tennis court. Both the mirror and sunshade won't fit onto the rocket fully open, so both will fold up and open once Webb is in outer space. Webb will reside in an orbit about 1.5 million km (1 million miles) from the Earth.
The HST's primary mirror is 2.4 meters (m), or about 95 inches, in diameter. The JWST's primary mirror is almost three times larger in diameter (see Figure 2 below), and it collects a bit more than seven times as much light. The JWST will be able to see about three times farther into the early Universe than does the HST—far enough to see the very first light in the Universe!
To learn about multiple-mirror optics and conditions in space by building a light collector similar to that of the primary mirror of the James Webb Space Telescope. The light collector will be illuminated using a heat lamp, and the intensity of light reflected from the mirrors will be measured from behind a protective "sunshield."
Interesting info. I was especially struck by the following statement:
"...This alignment is no small challenge. To get the proper mirror shape for the JWST to work, the mirror segments will need to unfold within a few nanometers (nm) of what engineers have calculated are the best positions. (A human hair is about 50,000 nm in diameter, so 5 nm is very small indeed!)..."
Don't confuse the sciencebuddies demo with how the actual telescope works. The sciencebuddies thing is not even pretending to create an image of any kind.
Remember the Intelligent Glass that can shape itself from the 1970s invented/ manufactured by Humanoido for large 1-meter and larger telescopes... it is now being merged with the technology of the Propeller Brain. iGlass will become a large part of the ULT project. Once again the Lab will cast a giant mirror of megalithic proportions. Work has already begun and a method for cutting ultra large hexagonals from iGlass is established.
Interesting info. I was especially struck by the following statement:
"...This alignment is no small challenge. To get the proper mirror shape for the JWST to work, the mirror segments will need to unfold within a few nanometers (nm) of what engineers have calculated are the best positions. (A human hair is about 50,000 nm in diameter, so 5 nm is very small indeed!)..."
Don't confuse the sciencebuddies demo with how the actual telescope works. The sciencebuddies thing is not even pretending to create an image of any kind.
Talk about splitting hairs..
I'm thinking ahead - these telescopes can form a different type of image, one with numbers and data representing heat. I think we could make a more realistic quantitative model by forming actual mirrors from infrared reflecting aluminum foil and putting a Parallax sensor at the secondary focus and detecting IR and making a map of the Sun. A small model could resolve the suns disk but you'll need to move it around with two servos in azimuth and altitude. So I think the model project has great merit for scale construction. It also shows one method of hexagonal mirror tiles used by several MMTs in use. Actually the small model you can build has more function than the large model seen in the photo.
Here are all related PIR posts found with the Big Brain Online Index, searched with the key "PIR," with schematics and code links. The Big Brain is using a Parallax PIR sensor as an in flight, launch and landing sensor, for the Big Brain's Airport and the Micro Space Program.
Cryogenics Fault Line Freeze Enhancing the Big Brain for Additional Brain Power
CRC Industries Europe BVBA is the suppler of Number 75 Fault Locator Cooling Agent for thermal applications. The canister is supplied with an external extension tube for delivery. Coolant comes in a large 400 ml canister for delivery of coolant to -49 degrees Centigrade. In Taiwan, the price is NT$499 which is about US$16.66. The similar product in China is US$40.
Cryogenics is currently being used to explore various characteristics of the Big Brain in enhancement modes to gain additional brain power and effect. The techniques of Cryo involve cooling the Propeller chip and observing its response under different experiments. These experiments involve running the Propeller chip at very low voltages, creating very low drain conditions, and exploring varying speeds of computational power, under different coolant situations.
For more information see www.crcind.com
Belgium - Tel +32 (0) 52 45 60 11
Touwslagerstraa 1 -9240 Zele
Big Brain Array guidelines for use of 75 Fault Location may appear in a future post. (see ramping up, ramping down, auto delivery, temperature variance, manual dispense, temp ranges)
Maybe somebody has developed ways of digitally filtering out some of these edge effects
One of the best techniques for enhancing the image is to take a video of the object and extract just the clear images shot in between moments of seeing when it changes to clear viewing. Then these images, which can number into the hundreds or thousands are stacked, and processed with Photoshop or a similar program.
If you're talking about edge effects on the mirror, if it's glass, that involves a complete refiguring, possibly going back to the polishing or grinding stage depending on the severity. Some people simply mask the outer edge but that makes a smaller telescope. If the mirror is from spun resin, the effect may be caused by mounting stress and could be corrected.
Robotic Telescope Systems Design Program - Part 4 How deep is your curve?
For spin casting resin, machine grinding glass or vacuum forming film - this program can help provide data to shape your new telescope mirror
Use this handy program to determine the shape of the mirror. Summary: Determines sagitta given mirror diameter and focal length
Program: TELESCOPE4.BAS
Part four of the TSDP is concerned with the relationship between a telescope mirror's focal length and F# as related to the curve of the mirror. How deep is the curve? Input a mirror diameter, the focal length, and the program automatically calculates the depth of the curve, known as sagitta.
Hogging out during mirror grinding is the removal of glass from the blank. Use this program when gauging the remaining amount of glass to remove. In the case of polymer and resin spin cast mirrors, the rotational energy resin viscosity are factors that contribute to the shape of the mirror.
Use TSDP to determine this shape. Remember, the depth in the center of the mirror is the mirror's sagitta which determines the mirror's focal length and focal ratio.
[SIZE=1]TELESCOPE SYSTEMS DESIGN PROGRAM - FILE: TELESCOPE4.BAS[/SIZE]
[SIZE=1]DETERMINE SAGITTA GIVEN MIRROR DIAMETER AND FOCAL LENGTH[/SIZE]
[SIZE=1]DIAMETER OF MIRROR IN INCHES? 6[/SIZE]
[SIZE=1]DESIRED FOCAL LENGTH IN INCHES? 32[/SIZE]
[SIZE=1]SAGITTA = 0.070312[/SIZE]
[SIZE=1]AGAIN? 1=YES 2=NO 1[/SIZE]
[SIZE=1]DIAMETER OF MIRROR IN INCHES? 60[/SIZE]
[SIZE=1]DESIRED FOCAL LENGTH IN INCHES? 240[/SIZE]
[SIZE=1]SAGITTA = 0.9375[/SIZE]
[SIZE=1]AGAIN? 1=YES 2=NO 1[/SIZE][SIZE=1]
[/SIZE]
[SIZE=1]DIAMETER OF MIRROR IN INCHES? 60[/SIZE]
[SIZE=1]DESIRED FOCAL LENGTH IN INCHES? 72[/SIZE]
[SIZE=1]SAGITTA = 3.125[/SIZE]
[SIZE=1]AGAIN? 1=YES 2=NO 2[/SIZE]
[SIZE=1]BYE[/SIZE]
[SIZE=1]>[/SIZE]
Note: When running the program, remember to use the actual focal length and not the F#. For example, with a 6-inch diameter telescope, do not input 5 for F5 but rather input 30 which is the result of F5.
[SIZE=1] ' Program listing[/SIZE]
[SIZE=1]10 ' TELESCOPE SYSTEMS DESIGN PROGRAM BY HUMANOIDO[/SIZE]
[SIZE=1]20 ' PART 4: DETERMINE SAGITTA GIVEN MIRROR DIAMETER AND FOCAL LENGTH[/SIZE]
[SIZE=1]30 cls[/SIZE]
[SIZE=1]40 print "TELESCOPE SYSTEMS DESIGN PROGRAM - FILE: TELESCOPE4.BAS"[/SIZE]
[SIZE=1]50 print "DETERMINE SAGITTA GIVEN MIRROR DIAMETER AND FOCAL LENGHT"[/SIZE]
[SIZE=1]60 input "DIAMETER OF MIRROR IN INCHES? ";d[/SIZE]
[SIZE=1]70 input "DESIRED FOCAL LENGTH IN INCHES? ";fl[/SIZE]
[SIZE=1]80 s = (d/2)*(d/2)/(4*fl)[/SIZE]
[SIZE=1]90 print "SAGITTA = ";s[/SIZE]
[SIZE=1]100 input "AGAIN? 1=YES 2=NO ";r[/SIZE]
[SIZE=1]110 if r = 1 then print[/SIZE]
[SIZE=1]120 if r < 1 then 100[/SIZE]
[SIZE=1]130 if r > 2 then 100[/SIZE]
[SIZE=1]140 if r = 1 then 60[/SIZE]
[SIZE=1]150 print "BYE"[/SIZE]
Small Mirrors
Use small mirrors, one per lens, to reflect and divert the image to a common focal point.
Experiment
Feel free to experiment with the design using pyramid prisms and other optics to create a more simple mechanism of in-common multiple focal points.
Alignment Agents
Use the hands mechanics (in addition to the primary lens mount) to hold and adjust small mirrors to act as image focusing and alignment agents.
Annular Wooden Ring
For more than two or three main refracting elements, build an annular wooden or steel mounting ring to support the helping hands mechanics around the inside perimeter.
Use the TSDP
Use Part 3 of the TSDP to calculate the data for extra mirrors which are in the MLT or MMT configurations.
Use Fast F-Number
Keep image scale small and bright at fast F-numbers and no drive is needed for tracking when exposures are kept short.
Use Double Convex Glass
This keeps costs minimal and is superior to cheap plastic lenses.
Correct for Achromatism using IP
Image Processing can correct for achromatism in a simple way.
Filtering
Filter out achromatic aberrations etc. with a glass filter.
Show Results
Show your results through astro imaging of the Moon and other celestial objects.
The Big Brain's Water Universe Telescope Use One Million Drops of Water to View the Universe
"Build this massive telescope lens from one million drops of water!"
Remember when in science class you made a tiny magnifier from a drop of water (or how you can magnify images from a clear glass of water)? Now imagine if that drop of water was one million times larger and could view the Universe!
Here's our alternate solution to the Mercury Spinning telescope Mirror. The Water Lens. The water lens has many advantages.
Safe, nontoxic
Easy to construct
No need to spin the water lens
Water is inexpensive
Easily replenishes
Disposable
Can be emptied & transported at light weight
Focal Length is determined by bag sag
Made from common household items
Mounting is simple
No drive motors needed
Uses a static mount
Lens is pure with no defects
Cannot crack
Quality determined by the water mount clarity
No secondary obstruction
Bubbles removed by settling
Refractor design
Bag mounting & water determine Focal Length
Capable of varying FL
Handles very deep or shallow curves
Shape assumes a perfect parabola by gravity
Mounts with simple leveling
Can equal a Schmidt Camera for fast imaging
Excels at long FL with less water
Numerous science possible
What can you do with one million drops of water? The science is remarkable. Stay tuned for detailed information on how to build your own million water drop telescope and how to use it for cutting edge science...
The math. One million drops of water equals 50,000 milliliters which equals 50 liters of water. Fifty liters of water is equal to 13.2 US Gallons. This is our large telescope and lens. You can also build smaller telescopes from smaller water lenses using less water and smaller water mounts.
Comments
Increasingly large modern telescopes tend to be large units of individual hexagonal mirrors. They are less expensive to make, take less time to make, are less complicated in grinding, polishing, figuring, spinning, have less physical challenges to move, transport, ship, many companies can work on the multiplicity of optics at the same time, and the casting of many smaller mirrors offer many solutions that one big mirror cannot solve. Some considerations are weight, mounting, manufacturing, cost, supply time, thermal qualities, stress, flexure, etc.
True. But I don't know of anyone who's made a large telescope from a multitude of lenses. I'm sure it's not impossible, but I'm guessing it's much harder to perform adaptive optics with lenses (vs. mirrors). I think the key to the success of MMTs was they developed not only computer control of the mirror surfaces but also a way of making larger mirrors using some kind of spin casting at about the same historical time.
One of the results we're looking for is the addition of multiple smaller primary objectives to create a larger telescope which functions like a much larger single mirror which would meet project objectives.
The multiple lens project MLT and the ULT MMT mirror-based project are two different projects. The MLT won't be upscaled beyond the largest refracting elements that I have access to which is around 5 to 10 inches.
There is another lensing project that may use lenses 50 to 100-inches in diameter, larger than the Yerkes 40-inch refractor, but I don't see putting together a multiple lens MLT using these. As expected, the weight, around 500 to 1000 pounds will be a limiting factor.
Facilities to spin cast a thousand inch mirror would be prohibitively expensive and challenging, and some will say a single mirror of that size will fail, but consider that I can more likely handle ten 100 inch mirrors. At some point size won't matter because the project will become prohibitively expensive.
A million inch diameter refractor for space applications?
A new type of telescope is currently being considered by the Big Brain is one that uses many small polymer lenses to make one giant telescope objective. The small lenses could easily number into the thousands with production techniques. These lenses in theory could produce an image of clarity rivaling large whole mirrors. Somewhat similar to the eye of a fly, the many elements would be contained within the outlined shape of a much larger objective. How big? A thousand 1-inch lenses will make the equivalent of a 1,000 inch lens.
Apps for the Fly Eye Telescope would serve space. Taken up over several rocket flights, millions of Fly Eye lenses could be assembled into a million inch telescope. The lenses weigh almost nothing, and thermosetting resins are already well researched and developed for applications in space.
It looks like astronomers increased the size of refractors up to 40-inches. An article in SKy & Telescope talked about some of the challenges faced with the weight of this large objective. I don't know of any very large multiple primary lens refractor telescopes. However, for the amateur scientist exploring the uniqueness of a small refractor multiple lens telescope, the mounting of the individual elements is not a weight problem and the project can serve a very useful purpose. The max diameter refracting lenses I have access to are all relatively light in weight. On the other hand, the largest single element refractor in the world is the 40 inch Yerkes Observatory telescope. The objective lens weighs 225 Kg.
The flip side of this is that as the materials change from glass to polymer materials, the weight reduces and the 40 inch barrier will no longer apply.
http://www.astrosurf.com/re/building_large_telescopes_refractors.pdf
http://en.wikipedia.org/wiki/Yerkes_Observatory
Results of MLT Experiments
The first night out with the Multiple Lens Telescope produced this first image
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Experiments went well with the "conventional lensing" to temporarily rig a multiple lens telescope. The importance of this was to test optical quality and the effects of lensing additives. A multiple lens telescope has the benefits same as adding mirrors together in MMT configurations. The conclusion of this experiment indicates the lenses can follow a curved substrate with one central focal point. The mount of these particular discrete elements will become a focus in the future. Will each simple attach to the substrate or will they use an alt-azimuth micro-mount? More tests and experiments will follow.
Which servo to use - standard or continuous rotation?
One element to examine in the case of the Walking Telescope is the distance the "cage" must walk. Standard servos that provide the motion can move through approximately 270 degrees. Gearing this from the feed horn can be an effective and low cost, Propeller driven, method to gain the telescoping drive.
But exactly how far must the secondary walk? First we need to consider the transforming and morphing application set forth by the VARFL and the Intelligent Glass.
This leads to the Intelligent Telescope which will have a number of configurations stored in the Propeller chip(s). Take a 6.375simple example. Convert and morph from a RFT telescope to a Schmidt camera (lenseless design). Our telescope is a 4.25 inch, the RFT is F3 and the Schmidt Camera is F1.5.
First we need to know the FL of the primary in each instant. The RFT is 12.75 inches and the Schmidt Camera is 6.375 inches. The difference is 6.375 inches. The telescope must walk this distance to properly transform.
However, more extreme cases exist. Take for example the LFT telescope at FL=60 inches at F10 and the Dobsonian at f4. The dob has a focal length of 24-inches. To transform from the LFT into the Dob requires a walk distance of 36 inches which is 3-feet or a full yard long!
A standard servo will not accommodate most transforming configurations. A continuous rotation servo may benefit this arrangement but it will need an encoder to count and track focal length position. Another possibility is a stepper motor but we are committed to using servos at this time.
with the MLT Multiple Lens Telescope
First Light: This is the first setup of the MLT Multiple Lens Telescope
for optical testing.
The round image at left is the Full Moon as imaged through the MLT for
the first time. Note the clarity and sharpness of the globe and the uniform
proportions.
Multiple Lens Telescope
We can't help but be excited about the first performance images returned from the MLT Multiple Lens Telescope. These large refracting elements were set up to image the Moon, as seen between the crack of two tall skyscrapers during the weekend.
Equipment was set on top of a designer sidewalk block. The image of the Moon was cast onto a sheet of 8 1/2 x 11-inch paper and photo'd with a SONY Cybershot.
The interesting part about this experiment was the number of people passing by who were interested in what I was doing.
The refractor lens has a smooth exceptional figure as seen in
the light of the Moon
Attestation to the fine quality of the refracting elements
in the MLT, this lunar image shows three sharp vicinity
stars in the same field of view. Exposure is less than 1
second.
Not easy to locate - The Moon was found in the crack between two
skyscrapers after walking several city blocks in the Capitol City of Taipei.
The brightest image in the lens is the Moon.
Revealing, for the first time, the key to making a successful MLT telescope
What is the key to successfully building the MLT Multiple Lens Telescope?
The secret is in holding and adjusting multiple refractor lenses. But the question is how to hold and focus the image of two lenses at the same time?
The key to making a successful MLT is contained in two boxes. Each box contains a 3.5-inch diameter double convex refracting glass element, an objective mount, and "Helping Hands."
Helping Hands hold the lenses and position and reposition the lens in any direction
Nearly every electronics enthusiast is familiar with the proverbial helping hands that can hold a printed circuit board and position it with a magnifying glass held above the work material for closeup viewing.
Two Helping Hands kits were purchased at the electronic parts store. This is model SN-392 from Pro's Kit. The cost is US$10 each. The reason the SN-392 works so well is for a couple of reasons. First, the magnifying element is pure glass and finely figured, and produces great images. Second, from one box tested to the next, the focal length of multiple refracting lenses are identical!
Specifications - 1st MLT Multiple Lens Telescope
Diameter of each lens - 3.5 inches
Number of lenses - two
Resolving power - equal to a 7-inch refractor
Light gathering power - equal to a 5-inch
Type of lenses - double convex
Project cost - $20
Mounting Type - helping hands
Test subject - the Moon
Telescope Systems Design Program TSDP
Running part 3 of the Telescope Systems design program gives the information for MLT mode. Though designed for multiple mirrors, the program works just as well with multiple refractor lenses. Here we can see that two 3.5 inch lenses can be equal in resolution to a 7 inch refractor and in light gathering power to a 5 inch refractor.
The results are surprising!
How can relatively tiny lenses that are only 3 and a half inches in diameter end up equaling a 70-inch diameter telescope? The largest refracting telescope in the world is only 40-inches in diameter..
At a cost of ten dollars per element, it would be reasonable to create a hundred or two hundred dollar telescope. Let's take a look at the results of the design.
For 10 lenses ($100)
* Equal to a 35-inch diameter telescope in resolving power
* Equal to a 11-inch diameter telescope in light gathering power
For 20 lenses ($200)
* Equal to a 70-inch diameter telescope in resolving power
* Equal to a 16-inch diameter telescope in light gathering power
Mirrors by Comparison - a Cost Analysis
If you did this telescope project with a single 70-inch mirror, it could cost several million dollars. If one considers the cost of a 16-inch mirror, the cost can easily range into $2,000.000 or more. That does not include the parts required to build the massive telescope. The cost quoted to build the MLT includes the mount.
The results are remarkable. By putting together 10 or 20 lenses, up to a 70-inch telescope can be created! Here's the tech info we need - run part 3 of the TSDP code and extract the data.
Today there are numerous AO designs, some of which are of great complexity. In the simplest use form, one can buy an off the shelf AO unit and connect it to the eyepiece and start observing. I should clarify that my work in the 1970s was the development of active optics systems that flex and control the entire primary mirror. Although the mirror is a single surface, its figure is shaped and modified by robot with 144 active locations or zonal figure points. For the modern version, see the post for Intelligent Glass.
http://en.wikipedia.org/wiki/Adaptive_optics
I suggest you get a copy of "Telescope Optics" by Rutten and van Venrooij.
http://www.willbell.com/tm/tm6.htm
Thanks for the good suggestion - it looks like a very interesting book and could be very useful for lots of info including the ray tracing software. That's also a good link - I have half of the books listed and plan to obtain the remainder.
As of interest, I see a book listed there about making a doublet lens, by Norman Remer. It talks about a 6-inch refractor, though the process would apply to larger lenses. I had a 40-inch lens a few years ago that would have made a nice refractor telescope, in a tie with the world's largest at Yerkes Observatory, but as mentioned, the weight and flex correction would make one big and massive telescope bigger than Lick Observatory!
http://www.willbell.com/TM/refractor-telescope.htm
2. The lenses surrounding the central lens form their images off-axis, in the same way that pieces of a Fresnel lens would. This almost certainly precludes cheap lenses.
-Phil
That book recommendation makes me think of a recommendation - keep your books located high up. My main library was 40-feet long and located up in the observatory above my garage and everything was always safe and "high and dry." But when I moved the library to a lower level, the entire city was flooded in the Spring season and I lost half my books. Many of those were astronomy books. This makes a good opportunity to rebuild the library at the new observatory and get lots of new books at the same time. As another recommendation, if you think your eyesight is getting too old for adding books to your reading library, email me and I'll tell you about a new noninvasive treatment that will make you think you're 20 again.
Just a thought:
http://lambdares.com/education/oslo_edu
For those who wish to learn astronomical information about the working validity of multiple objective mechanics and concepts that have remained in successful use for decades and led to numerous astronomical discoveries and new data, I would suggest a referral to the SPIES technical documents library on the construction and design for MMTs which contain information that can be scaled up or down and simplified for working amateur applications at low cost.
You're a gold mine of information! Thanks again - I may need to get a pc to supplement the mac but first I'll do some research on ray tracing at the Astrophysics Dept. where they're heavy into macs... Actually where OSLO says working with 10 surfaces would be a restriction, it's not. Consider working with eight 72 inch objectives. In terms of size, reaching the goal of a 200 inch mirror would be satisfied for the ULT project with 8 surfaces as it would equal a 204 inch mirror for light gathering.
The Big Brain worked with a Fresnel lens to enlarge the TV screen and this type of lens introduces so much distortion that it was found to be totally unusable. There's a man who produces very large and so called accurate Fresnel lenses and I contacted him. He tells me several people considered his lenses for astronomical use but as far as success, he never heard back from anyone. Nor can he quote any optical specifications for the lenses, which makes any apps for it mute.
http://en.wikipedia.org/wiki/Fresnel_lens
A Fresnel lens (
However, although one may consider a Fresnel to be a cheap lens, there are other cheap lenses from a money viewpoint that are mass produced and perform quite well in forming good images. In the future, we will look at using some of these lenses. Overseas, I may have a source for tens of thousands of these lenses so it would be advantageous to do experimenting with some in multiple configs. and come up with some giant fun-for-experimenting Fly Eye multiple lensing telescopes.
Models have working mirrors that measure reflectivity using sunlight
Optical Telescope? The Webb is designed as an Infrared Telescope beyond the optical vision of humans. Not all telescopes operate in optical ranges. The Big Brain, although has announced the ULT Project, Ultra Large Telescope, has not announced the design or the wavelength of operation.
When does a mirror have six sides?
The illustration shows one of two methods of building a multiple
mirror telescope MMT. This method has no mirror in the center to
facilitate design.
A gold mirror - JWST completes the gold coating of it's telescope
mirrors with segment C1. A microscopically thin layer of gold
maximizes the reflectivity of these mirrors to infrared light.
The ULT Project is fully capable of producing gold cast coated
polymer iGlass mirrors. The expense on a gold mirror is greater.
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http://www.sciencebuddies.org/science-fair-projects/project_ideas/Phys_p082.shtml
Read about the telescope directly from NASA
http://www.jwst.nasa.gov/
Webb will have a large mirror, 6.5 meters (21.3 feet) in diameter and a sunshield the size of a tennis court. Both the mirror and sunshade won't fit onto the rocket fully open, so both will fold up and open once Webb is in outer space. Webb will reside in an orbit about 1.5 million km (1 million miles) from the Earth.
The HST's primary mirror is 2.4 meters (m), or about 95 inches, in diameter. The JWST's primary mirror is almost three times larger in diameter (see Figure 2 below), and it collects a bit more than seven times as much light. The JWST will be able to see about three times farther into the early Universe than does the HST—far enough to see the very first light in the Universe!
To learn about multiple-mirror optics and conditions in space by building a light collector similar to that of the primary mirror of the James Webb Space Telescope. The light collector will be illuminated using a heat lamp, and the intensity of light reflected from the mirrors will be measured from behind a protective "sunshield."
http://www.sciencebuddies.org/science-fair-projects/project_ideas/Phys_p082.shtml
This scale model gives an idea of the actual size of the James Webb Telescope.
http://www.sciencebuddies.org/science-fair-projects/project_ideas/Phys_p082.shtml
NASA - notice the spacing between the mirror mounts
http://www.jwst.nasa.gov/images_backplane_2.html
http://webbtelescope.org/webb_telescope/
http://www.jwst.nasa.gov/images_mirror76.html
Interesting info. I was especially struck by the following statement:
"...This alignment is no small challenge. To get the proper mirror shape for the JWST to work, the mirror segments will need to unfold within a few nanometers (nm) of what engineers have calculated are the best positions. (A human hair is about 50,000 nm in diameter, so 5 nm is very small indeed!)..."
Don't confuse the sciencebuddies demo with how the actual telescope works. The sciencebuddies thing is not even pretending to create an image of any kind.
Remember the Intelligent Glass that can shape itself from the 1970s invented/ manufactured by Humanoido for large 1-meter and larger telescopes... it is now being merged with the technology of the Propeller Brain. iGlass will become a large part of the ULT project. Once again the Lab will cast a giant mirror of megalithic proportions. Work has already begun and a method for cutting ultra large hexagonals from iGlass is established.
Jame Webb Model, Specifications
Talk about splitting hairs..
I'm thinking ahead - these telescopes can form a different type of image, one with numbers and data representing heat. I think we could make a more realistic quantitative model by forming actual mirrors from infrared reflecting aluminum foil and putting a Parallax sensor at the secondary focus and detecting IR and making a map of the Sun. A small model could resolve the suns disk but you'll need to move it around with two servos in azimuth and altitude. So I think the model project has great merit for scale construction. It also shows one method of hexagonal mirror tiles used by several MMTs in use. Actually the small model you can build has more function than the large model seen in the photo.
Here are all related PIR posts found with the Big Brain Online Index, searched with the key "PIR," with schematics and code links. The Big Brain is using a Parallax PIR sensor as an in flight, launch and landing sensor, for the Big Brain's Airport and the Micro Space Program.
Propeller PIR Motion Sensor for Flight Recorder
http://forums.parallax.com/showthread.php?124495-Fill-the-Big-Brain&p=1029568&viewfull=1#post1029568
Big Brain Propeller Airport PIR Build
Aircraft Motion Detector Machine for launch, flight, recovery
http://forums.parallax.com/showthread.php?124495-Fill-the-Big-Brain&p=1032658&viewfull=1#post1032658
PIR Code Written for the Big Brain
pir_air_LED.spin
http://forums.parallax.com/attachment.php?attachmentid=84773&d=1314945455
PIR Materials Transparency Test
For the Robotic Micro Space Airport
http://forums.parallax.com/showthread.php?124495-Fill-the-Big-Brain&p=1034028&viewfull=1#post1034028
Brain Senses - Focus on Vision Part 3
Human Detection
http://forums.parallax.com/showthread.php?124495-Fill-the-Big-Brain&p=977870&viewfull=1#post977870
Enhancing the Big Brain for Additional Brain Power
CRC Industries Europe BVBA is the suppler of Number 75 Fault Locator Cooling Agent for thermal applications. The canister is supplied with an external extension tube for delivery. Coolant comes in a large 400 ml canister for delivery of coolant to -49 degrees Centigrade. In Taiwan, the price is NT$499 which is about US$16.66. The similar product in China is US$40.
Cryogenics is currently being used to explore various characteristics of the Big Brain in enhancement modes to gain additional brain power and effect. The techniques of Cryo involve cooling the Propeller chip and observing its response under different experiments. These experiments involve running the Propeller chip at very low voltages, creating very low drain conditions, and exploring varying speeds of computational power, under different coolant situations.
For more information see www.crcind.com
Belgium - Tel +32 (0) 52 45 60 11
Touwslagerstraa 1 -9240 Zele
Big Brain Array guidelines for use of 75 Fault Location may appear in a future post. (see ramping up, ramping down, auto delivery, temperature variance, manual dispense, temp ranges)
One of the best techniques for enhancing the image is to take a video of the object and extract just the clear images shot in between moments of seeing when it changes to clear viewing. Then these images, which can number into the hundreds or thousands are stacked, and processed with Photoshop or a similar program.
If you're talking about edge effects on the mirror, if it's glass, that involves a complete refiguring, possibly going back to the polishing or grinding stage depending on the severity. Some people simply mask the outer edge but that makes a smaller telescope. If the mirror is from spun resin, the effect may be caused by mounting stress and could be corrected.
How deep is your curve?
For spin casting resin, machine grinding glass or vacuum forming film -
this program can help provide data to shape your new telescope mirror
Use this handy program to determine the shape of the mirror.
Summary: Determines sagitta given mirror diameter and focal length
Program: TELESCOPE4.BAS
Part four of the TSDP is concerned with the relationship between a telescope mirror's focal length and F# as related to the curve of the mirror. How deep is the curve? Input a mirror diameter, the focal length, and the program automatically calculates the depth of the curve, known as sagitta.
Hogging out during mirror grinding is the removal of glass from the blank. Use this program when gauging the remaining amount of glass to remove. In the case of polymer and resin spin cast mirrors, the rotational energy resin viscosity are factors that contribute to the shape of the mirror.
Use TSDP to determine this shape. Remember, the depth in the center of the mirror is the mirror's sagitta which determines the mirror's focal length and focal ratio.
Note: When running the program, remember to use the actual focal length and not the F#. For example, with a 6-inch diameter telescope, do not input 5 for F5 but rather input 30 which is the result of F5.
Small Mirrors
Use small mirrors, one per lens, to reflect and divert the image to a common focal point.
Experiment
Feel free to experiment with the design using pyramid prisms and other optics to create a more simple mechanism of in-common multiple focal points.
Alignment Agents
Use the hands mechanics (in addition to the primary lens mount) to hold and adjust small mirrors to act as image focusing and alignment agents.
Annular Wooden Ring
For more than two or three main refracting elements, build an annular wooden or steel mounting ring to support the helping hands mechanics around the inside perimeter.
Use the TSDP
Use Part 3 of the TSDP to calculate the data for extra mirrors which are in the MLT or MMT configurations.
Use Fast F-Number
Keep image scale small and bright at fast F-numbers and no drive is needed for tracking when exposures are kept short.
Use Double Convex Glass
This keeps costs minimal and is superior to cheap plastic lenses.
Correct for Achromatism using IP
Image Processing can correct for achromatism in a simple way.
Filtering
Filter out achromatic aberrations etc. with a glass filter.
Show Results
Show your results through astro imaging of the Moon and other celestial objects.
Use One Million Drops of Water to View the Universe
"Build this massive telescope lens from one million drops of water!"
Remember when in science class you made a tiny magnifier from a drop of water (or how you can magnify images from a clear glass of water)? Now imagine if that drop of water was one million times larger and could view the Universe!
Here's our alternate solution to the Mercury Spinning telescope Mirror. The Water Lens. The water lens has many advantages.
- Safe, nontoxic
- Easy to construct
- No need to spin the water lens
- Water is inexpensive
- Easily replenishes
- Disposable
- Can be emptied & transported at light weight
- Focal Length is determined by bag sag
- Made from common household items
- Mounting is simple
- No drive motors needed
- Uses a static mount
- Lens is pure with no defects
- Cannot crack
- Quality determined by the water mount clarity
- No secondary obstruction
- Bubbles removed by settling
- Refractor design
- Bag mounting & water determine Focal Length
- Capable of varying FL
- Handles very deep or shallow curves
- Shape assumes a perfect parabola by gravity
- Mounts with simple leveling
- Can equal a Schmidt Camera for fast imaging
- Excels at long FL with less water
- Numerous science possible
What can you do with one million drops of water? The science is remarkable. Stay tuned for detailed information on how to build your own million water drop telescope and how to use it for cutting edge science...The math. One million drops of water equals 50,000 milliliters which equals 50 liters of water. Fifty liters of water is equal to 13.2 US Gallons. This is our large telescope and lens. You can also build smaller telescopes from smaller water lenses using less water and smaller water mounts.
Convert Drops of Water to ML
http://convert-to.com/conversion/volume/convert-drop-to-ml.html
Convert ML to L
http://www.convertunits.com/from/ml/to/l