DIY ULF Lenses - 3D printing resin, epoxy casting or sand casting?

[Qeb]

Greetings everyone,

I hope all are well.
Thank you in advance for reading this.

This post is regarding home made resin/epoxy/plastic lenses (elements and housing).
My dream is to shoot ultralarge format/mammoth format portraits in the future.

My obvious inspirations are, Richard Learoyd and Ian Ruhter.
For instant film shooters that inspire me, I would say I really like work by
Elsa Dorfman, Cathleen Naundorf and Joyce Tenneson.

This past week, I've been researching home made lenses.
There seems to be a few ways to do this.

1. SLA 3D printing with liquid resin
2. plastic resin casting
3. casting sand/glass
4. construction from a lathe or cnc mill

Susan Burnstine is very inspiring in regards to diy lenses.
But one of the driving forces besides auteurism (I think that's the word),
is that, mammoth format lenses are just way too expensive and rare.


Has anyone tried 3d printing or resin/epoxy cast camera lenses?


I'm leaning towards 3d printing or resin casting, but each has incredible challenges.
3D printing, would cost a lot for due SLA printers and resin being so expensive.
And with epoxy casting, it's really hard with out an existing glass element to make a mold from.

Also, I have no clue which lens design would be the easiest to diy but still have relatively acceptable image quality.

I think both Lomography and Holga make plastic lenses, but they are probably injection molded, which has it's challenges also.



Sorry, if this has been discussed on the forum already, I didn't find any good detailed threads.

But, if people are interested in collaborating on experimenting with diy 3d printed or epoxy cast lenses, I would definitely be interested in teaming up.
I'm not rich, but I would try to support anyone who wants to play with this project idea.


Thanks so much for reading this!
Take care and be well :)

Best regards,
Kevin H. (Toronto, Canada)

~ ~ ~ ~ ~

Here are some links for others who might be interested in diy lenses:


- 3d Printing

A peer reviewed paper on 3d printing lenses
https://opg.optica.org/oe/fulltext.cfm?uri=oe-27-21-30405&id=422075


https://www.sciencedaily.com/releases/2018/03/180327094013.htm

https://formlabs.com/blog/creating-camera-lenses-with-stereolithography/





-Casting Epoxy Lenses

https://hackaday.com/2021/12/09/the-ins-and-outs-of-casting-lenses-from-epoxy/

https://www.youtube.com/watch?v=TN9tHJXXlKs

https://petapixel.com/2021/07/16/photographer-makes-diy-lenses-with-cake-molds-and-epoxy/

https://www.diyphotography.net/cloning-lens-elements-using-silicone-and-epoxy-resin/

https://medium.com/jaycon-systems/optical-fabrication-part-2-making-lenses-using-silicone-molding-194ea81cd273




- A very new way of making epoxy resin lenses based on bouncy and surface tension

https://scitechdaily.com/fabricating-complex-optical-components-from-fluids-for-eyewear-cameras-and-telescopes/


-Injection Mold and Machining

*** https://www.youtube.com/watch?v=ZW2lj0KjyT8

https://www.youtube.com/watch?v=FcBrcSfIeVQ
https://www.youtube.com/watch?v=JNXgHbBIRYQ



- Casting with sand
https://www.youtube.com/watch?v=miuhxhodpiQ


Additional links:

https://www.zeonex.com/optics.aspx.html

https://www.rp-photonics.com/plastic_optics.html

https://www.sciencedirect.com/topics/engineering/optical-plastic

[Ethan]

I think casting will produce far better lenses than printing, even with SLA printers I think you'll get small deformations inside which can cause trouble.

I think the easiest route would be to 3d print a form (not SLA printed, could do FDM and then smooth), and then create a mold based on that.

I don't know much about lens design, but I think you would need to design your own mold, instead of casting an existing lens. The properties of a lens depend both on its shape, but also the optical properties of the glass used. A plastic would not have the same properties as the glass used in a normal lens, so casting a plastic lens based on the mold of a glass lens would not produce usable optics I think.

I know there are lens design programs which can take the optical properties of a material and allow you to design lenses based on them. Some people were discussing lens design in another thread recently, maybe some of those guys who have used the programs can help you figure out how to design a lens. Since people have created cast plastic lenses before, if you can contact them, maybe they can help you with the optical properties of resin.

[Tin Can]

http://www.re-inventedphotoequip.com/Formats.html

I have the 790 mm

[Oslolens]

Interesting info, not going there myself.

The most easy way may be to get what you need from here:

https://www.amazingcameraobscura.co.uk/

But what I did was to order adapter rings for my Ilex #5 shutter (max opening 63mm) from SKGRIMES.COM for 77mm filter threads front and 72mm back. I mount achromatic close-up lenses from Canon, Nikon and Pentax, The longest I got of identical lenses are the 1400mm Leica Elpro 4, making a sharp 710mm f16 with curved film plane. I do not have larger than 8x10, but the 710mm lens is sharp out to a circle of 540mm before going dark due to too long tube or should i say too many adapter rings.

Also simpler lenses like a pair of Bronica 1 make a fabulous 500mm lens.

Even cheaper option would be to buy a Copal #3S (max opening 45mm) found in the 250mm soft focus Fujinon-SF. This has 56mm threads, but I cannot guarantee there will be room for a random ring found online.



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[nolindan]

http://www.re-inventedphotoequip.com/Formats.html

+1

You might also look at the inventory at Surplus Shed. A 900mm f11 mounted achromat for $42 https://www.surplusshed.com/pages/item/L3002.html

[Jody_S]

Thank you for the links, I will read/watch when I have some time. I've wondered if plastic was a suitable medium for DIY lens-making, of course everything would have to be re-computed using available types of plastic. The formulas for historic lenses are readily available, and if using a color filter shooting B&W, one should be able to get reasonable performance. I was thinking of re-creating Hill's Sky Camera lens for 5x7 or 8x10 format. Yes I know that would be a mammoth lens, hence my interest in using plastic.

[Qeb]

Hi Ethan!

Thanks so much for the advice to do a hybrid process!
Great idea :)
Yep, I've reached out to a couple of members but they must be very busy, no worries :)

Thank again Ethan for the first reply!

~~~

Thanks Tin Can, I forgot about that website/those products!

I would really like to have more ownership over a lens.
I think also, I might need more coverage/larger image circle :(

~~~

Thanks Oslolens for your reply also!
I'm going to go over your advice more

~~~

Hello Jody_S,
Wow Montreal eh?
How much snow do you people still have? haha
Toronto was a mess!

Oh wow, that Hill's Sky Camera looks amazing.

I hope if you move forward with a diy lens from plastic, we can keep in touch and share notes :)

Have a good weekend.

[Maris Rusis]

Making ULF lenses is going to be steep engineering challenge but assembling a ULF lens from existing components can be easy, quick, and cheap. Here's what I would do:

Get two 75mm diameter standard eyeglass blanks, one +3 dioptre power and the other one -3 dioptre power. Place them together not touching but 3mm apart. The combination delivers a focal length of about 12 feet and throws a reasonable image about 12 feet across. Big enough? Changing the spacing changes the focal length and the size of the projected image. There are many possibilities. Check out Gullstrand's Equation to run the numbers.

[Paul Ron]

well if you are going huge... why not use a shipping container as your camera and just drill a small hole on one end as a pinhole camera? camera obscura.

[Qeb]

Hi Maris, I'm watching a series of instructional videos on optical design currently.
I wonder if your design would have a very high number aperture (slow lens)
Thanks for the reply
~~~
Hi Paul Ron, I'm in contact with someone that can build a 60x60 maybe 70x70" camera for studio portraits.
I've been designing in my head a a support system where I can get more angles than just level.
Thanks :)

[Tin Can]

Lots on YouTube


ULF DIY LENS

Many ways

[Paul Ron]

when i was a kid (15yr old) i helped a friend move. us kids had to ride in the back with the furniture. as we went, i noticed images on the walls. i can see the other cars and trees going by. the source of the images were missing pop rivets... it blew me away n gave me an idea to make a camera from a cardboard refrigerator box and using 11x14 printing paper. it was fun doing paper negatives making contact prints with them. i especially enjoyed being in the box while taking my pictures.

[Maris Rusis]

Hi Maris, I'm watching a series of instructional videos on optical design currently.
I wonder if your design would have a very high number aperture (slow lens)
Thanks for the reply ...
High aperture number? Yes. About f45 for the example I quoted. The limitation of the "opposing dioptres" approach is the scarcity of large diameter matched pairs of lenses.

[Oslolens]

High aperture number? Yes. About f45 for the example I quoted. The limitation of the "opposing dioptres" approach is the scarcity of large diameter matched pairs of lenses.Max i found is 138mm, and those needed a holder, but at a cost of $400 per lens. Good enough reason to limit one self to 95mm.

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[r_a_feldman]

I recently ran across a seller on eBay called “Mittenpaw” with individual Burke & James “laboratory optics” lenses in bi-convex, plano-convex, positive meniscus and negative meniscus, multiple diameters and focal lengths, that might be useful for home-made lenses. I have not bought any of them and have no connection to the seller.

[Nodda Duma]

Hi Kevin,

I think you emailed me similar question but I think my reply bounced. So I’m glad you posted here so I can share my thoughts.

This is not meant yo dissuade you in any way, but you should understand the challenges that you need to overcome. They are far greater than fabricating glass lenses.

Plastic lenses are of course injection molded and used for imaging lenses. However, due to the limited types of plastics (limited selection of optical properties), the ability to design high performance optics is severely constrained. This is why photographic use is typically constrained to low resolution disposable cameras and similar.

For simple optics, it’s theoretically feasible. *theoretically* Of course, the fun is in the difference between theoretical and the real-world. (It might seem shocking that a lens designer / engineering person mentions real world, but engineers are all about making actual things that have to work).

More important than the properties of plastic itself is understanding how it changes dimensionally when it is made. This is practically an art form in the injection molding world, and particularly critical for optics. It is not a linear relationship, so it can’t be modeled. In other words, what you end up with isn’t what you designed. You have to iterate, changing the modeled curvatures and dimensions until you get what you want. This includes surface accuracy, which should be a few fringes (repeatable).

For even the best 3D printers, the surface accuracy required isn’t sufficient to meet useable surface roughness. Optical surface roughness in the visible should be around 50 Angstroms. 3D printers provide a roughness about 2 orders of magnitude larger. So expect to post-polish (polishing plastic can be nightmarish). In addition, homogeneity (uniformity of optical properties in the bulk material) will be a problem. I don’t think 3D printers control the building up of layers sufficiently uniform to provide necessary bulk material uniformity.

Not to say it can’t be done, just want to make sure that you’re jumping in with eyes wide open if you want something a bit beyond the barely functioning piles of imaging goo typically seen in YouTube videos.

There is a lot of work and trial and error involved in figuring it out, and a lot of labor involved in getting it working even after printing (or molding) is complete. Plastic lenses — molded or printed — are not easier to make than glass lenses. That shouldn’t dissuade you, as anything worthy requires time and effort. It is useful to understand the challenges to overcome.

Cheers,
Jason

[Tin Can]

Water lenses?

[Qeb]

Thanks Tin Can, I'll keep looking maybe

~~~
Paul Ron, that's an awesome story!
My Uncle found a camera while on vacation and gave it to my dad who then gave it to me in Grade 6. hehehe
~~~

Thanks Maris Rusis!
I would like to do portraits so f/5.6 or as close to that is the goal
~~~

Thanks Oslolens for the prices and advice
~~~

Hey r_a_feldman!
I took a look at their ebay store page.
I'm not sure if this is the route to go.
I really wanted to make a lens with super large coverage
but also very large in diameter for speed.
Thanks again
~~~

Hey Nodda Duma!
Thank you for replying with a very detailed and caring post!

Okay, hmm, I'm not sure then how to move forward.
Maybe I will start looking for those rare 1800mm lenses.
I've been saving up for a few years for restoring a classic car,
but if I can find, let's say, one rare Nikkor 1800mm f/14, I would
invest in that and take my time on a DIY lens.
This would give me the most options in terms of the direction
in my art I want to take.

Maybe I should post in the "Wanted To Buy" section then... anyone have any leads? hahah

Okay, thanks everyone for the input!

[Nodda Duma]

Qeb,

I’d start by reaching out to Surplus Shed and asking if they have a meniscus lens in your desired focal length with a diameter capable of giving you an f/16 lens. Then, fabricate an f/22 diameter aperture (a hole) and play with the spacing between the meniscus and the aperture until the off axis bokeh looks pleasing. Concave side towards the aperture. This is a basic f/22 landscape lens and will be a good start. You ask for a larger lens so that you don’t vignette.

[Qeb]

Hey Nodda Duma,

Thanks for the reply, sorry for my slow one.

Could I ask you something?

Would a lens break the laws of physics if it could cover a square image of 50 inch by 50 inch at focus at infinity? (and have an aperture closer to f/5.6?)

Though I have an degree in art, I'm trying to work on a online tech platform.
So, if I make money with it, maybe there are companies out there that can do a custom lens.
I am assuming this would cost a lot of money, but it's for art!

Okay, I will send Surplus Shed a message as I didn't find anything with the search function.

Thanks so much again!
Cheers :)

[Oslolens]

If a 56 inch lens covers the format you need a 10 inch aperture to get f5.6, and slightly bigger lens elements. The picture would be less sharp if a set of meniscus lenses are used.

Very few photographers need f5.6. If Avedon used f16 on 8x10" what would be the benefit of such a large and bright lens?

And are you looking in to a sharp lens or soft or very soft?

I just got my 138mm tubus mounted, it contains a 450mm f3.6 balopticon lens and is heavy and cumbersome.
https://uploads.tapatalk-cdn.com/20220203/0c9356e44f8f489657a48bafe8266822.jpg

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[Nodda Duma]

Such a lens can be designed of course, but the design form and thus the cost would depend on the focal length. The simplest/cheapest for a normal or portrait focal length would be a Cooke triplet type. At 10” diameter aperture, the glass itself would cost ~$8k-$10k. Mechanicals would be another $2k-$4k. NRE would be $2k-$4k.

So the answer is, no it wouldn’t break the laws of physics. Just your wallet.

[Havoc]

"Liquid optics"? Nothing new, Herschel used it in one of his telescopes. 2 halves filled with liquid in between. Different liquids give different indexes. But you can go large without needing massive blocks of materials.

[John Layton]

hey...what about that guy that creates lenses out of ice? Is he still doing this?

[Qeb]

Sorry for my slow reply :(

~~~

Thanks Oslolens!

So, the emulsion will be very low/slow and I want to use constant lights instead of flash.
Thus I'm thinking I want the option to shorten my exposure time if needed.

Thanks for the photo upload!
~~~


Hey Nodda Duma, Thanks so much for your reply also.

That's awesome great news that lenses can be custom made at these sizes.

I'm not sure about the focal length. I do have a ULF camera that I intend to use when I make more money for a new darkroom and bigger studio (currently using the dining room).

Would you be able to recommend a lens focal length for 1:1 portrait and focus at infinity? Sorry, for my ignorance.

Would you also know any companies that would make this lens?

Is a 20" diameter lens impossible?


Thank you for letting me pick you brain Sir!

~~~

Be well everyone! :)

[Dan Fromm]

Would you be able to recommend a lens focal length for 1:1 portrait and focus at infinity?

Hmm. Getting 1:1 magnification at infinity needs a lens with an infinite focal length. You don't have infinite funds and the lens would be infinitely heavy. Are you sure that's what you meant?

What format is your ULF camera and what kind of portrait do you want to take? Focal length needed to fill the frame with a subject depends on film format and just what the subject is (face only, head and shoulders, ..., full body, full body + some surroundings).


Is a 20" diameter lens impossible?

Larger lenses have been made. Think refracting telescope. Also think about weight.

[Qeb]

Hey Dan Fromm,

Thanks for always chiming into my random posts :P :P :P

So, I'm getting I need two lenses, but I lack comprehension skills often.
(English is sort of my second language)

I noticed Richard Learoyd never does full body (full standing person) + surroundings.
What lens(es) (focal lengths and coverage) would I need to do half body but also full body at lets say 70"by70" (maximum).

I'm obviously dreaming a bit, but if my tech ideas are successful I might have the money to do all of this one day.
I mean I could get a lens or two now, but the lighting equipment and processors I need will be much much more than two custom lenses.

Sorry for this increasingly silly thread, I know people come here with similar goals.
But this is a long term dream and as I'm waiting on people with my tech ideas I thought I would use sometime to ask the hive mind some questions.

Thanks Dan and others :)

[Maris Rusis]

I am a sometime amateur astronomer and the subject of lenses has been fascinating.

Just for the record and just for interest large diameter lenses exist and the place where they are most often found is on the front of major refracting telescopes. It has been said with some truth that the cost of a lens and the difficulty of manufacture goes up according to the cube of the diameter. That's why there are so few really big optical quality lenses in the world.
A list of them is remarkably short:https://en.wikipedia.org/wiki/List_of_largest_optical_refracting_telescopes

It's possible to buy a big lens today. A contemporary example could come from a maker like CFF Telescopes ( I have no commercial connection) who offer a 200mm f6.5 refractor. The price is about $27000 dollars and most of that is in the objective lens.
A even bigger CFF telescope has a 230mm lens working at f7 priced at about $37000.

If there was a simple and cheap work-around for the problem of fabricating optical quality giant lenses they would not be so rare. But very rare they are.

[Dan Fromm]

I noticed Richard Learoyd never does full body (full standing person) + surroundings.
What lens(es) (focal lengths and coverage) would I need to do half body but also full body at lets say 70"by70" (maximum).

760/14 Apo Ronar. And a lot of light.

He started out with a 1200/12.5 Apo-Saphir, found it too long. But he doesn't shoot 70" x 70".

[Nodda Duma]

Cost increases exponentially with diameter, so expect any build involving 20” refractive lenses - which would be near the upper limit — would be $100k - $250k as a very rough guess.

[Havoc]

Would making it yourself be an option? No idea if you can buy an optical blank. But I once found in the library at uni a book about lab practices and grinding your own lenses and mirrors was part of it. It was manual grinding to boot. I remember something like a pole with a round table supporting the table and you had to go round it rubbing a second blank over it with some grinding material between both. One became convex, the other concave. If you limit yourself to b&w and add a filter to limit dispersion you might get away with it. Sadly I do not have a copy of the book and don't remember the title. Was a book from the '50s IIRC.

[Tin Can]

I buy grit from this very reasonable source

They also have blanks

https://gotgrit.com/


Would making it yourself be an option? No idea if you can buy an optical blank. But I once found in the library at uni a book about lab practices and grinding your own lenses and mirrors was part of it. It was manual grinding to boot. I remember something like a pole with a round table supporting the table and you had to go round it rubbing a second blank over it with some grinding material between both. One became convex, the other concave. If you limit yourself to b&w and add a filter to limit dispersion you might get away with it. Sadly I do not have a copy of the book and don't remember the title. Was a book from the '50s IIRC.

[maltfalc]

you could try spin casting lens elements in acrylic or epoxy. like this https://www.youtube.com/watch?v=r9X1GpcMRlE except the first layer becomes the mold for one side of the lens and a second layer becomes the lens itself. or just get something on aliexpress, they've got all sorts of oddball lenses.

[Tin Can]

Make a mylar mirror

Several ways on youtube

https://hackaday.com/2016/07/26/pressure-formed-parabolic-mirror-from-a-mylar-blanket/