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.c...0405&id=422075


https://www.sciencedaily.com/release...0327094013.htm

https://formlabs.com/blog/creating-c...eolithography/





-Casting Epoxy Lenses

https://hackaday.com/2021/12/09/the-...es-from-epoxy/

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

https://petapixel.com/2021/07/16/pho...lds-and-epoxy/

https://www.diyphotography.net/cloni...d-epoxy-resin/

https://medium.com/jaycon-systems/op...g-194ea81cd273




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

https://scitechdaily.com/fabricating...nd-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...ptical-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.



Sent fra min SM-G975F via Tapatalk

[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