Hybrid Pinhole/Glass Camera Optics

[@themrtomward]

For sure I am a fan of Joe Van Cleave videos.Thank you for your efforts Joe and for making them available to the world through the internet.I'm digging anything Crown Graphic or Speed Graphic related and pin hole info and various aperture info.

[@Sohail410_]

I recently started shooting medium format in a Holga wide pinhole camera and although I love the 6x12 negatives I want a 6x17 version. I wanted to try and put a large format lens in front of it but then have a pinhole at the back. This has been highly encouraging, thank you

[@JoePani1]

Great stuff. This (Optics) is what drew me to your channel to start. I still love your typewriter expertise as well. Keeep it uppp

[@IndianKD]

Very interesting! Thank you very much.

[@nathanjohansen7169]

Really interesting video. I love the distorted angle of view from a wide angle pinhole photograph, but always wanted something sharper. I wondered about using a glass lens to improve sharpness, but didn't know how to go about it. This gives me some ideas. Thanks for posting this!

[@BillPutnamPhoto]

Interesting. I was wondering, what happens if you put the optic behind the pinhole? Asking because I'm building, so to speak, a 4x5 pinhole lens around an old Copal #0 shutter. Ordered a .420mm pinhole aperture plate from a guy in Germany, and will put it in the Copal #0 shutter, then put on a 4x5 Linhof lensboard. I have a spare 90mm optic and can put the rear optic in the shutter as well.

[@DigitalMentorGroup]

The hybrid optics make sense for old Speed Graphic cameras, especially if they have worn out shutters.

[@Dwarvenchef]

Going to try this on my Linhof, my only lens so far is the 135mm. See what happens. Oh ya just found your Pod Cast, very cool.

[@PaleoPhotographie]

I have tried several old mono-lense cameras, much older than this Speed graphics, and the results were not as bad as you had. Well, not always, two times I had the same result but it was because the lens was monted upsidedown... I am curious to know the result if you reverse it.

[@minecrafthERCULES]

great explanation! Now I really want to use the overhead projector lens on my large format

[@Taran_of_Caer_Dallben]

Just like Nathan Johansen I am interested in wide angle pictures. Do you think this would work with a 60mm or 75mm lens? or would the image angle be limited by the aperture in front of the lens? Thank you very much for your videos and ideas, Joe!

[@Joe_VanCleave]

The single element meniscus lens will limit the angle of view. I advise you to experiment with it and see for yourself.

[@Taran_of_Caer_Dallben]

@@Joe_VanCleave I thought so, well, doing a mock-up with foam board etc should not be too difficult. Thank you!

[@Icosa1V]

How does this relate to hyper focal distance, with a regular lens? And also what about the f64 Club?

[@Joe_VanCleave]

Every aperture size and focal length combination will have its own ideal hyperfocal distance, including this. A person could design the glass lens to be a focal length equal to the hyperfocal distance for the camera-to-lens distance being used. Also, hyperfocal distance is only one optimization you could choose, depending on your desired image quality. To optimize sharpness of distant objects you may not want focus fixed at the hyperfocal distance, the same with close focus. So it’s possible a variable focus mechanism could be useful, depending on your needs and complexity of design you’re willing to live with. But those options lead to more complexities like zone focus settings (near, hyper & infinity for example) and maybe needing a view screen to determine focus - which would be difficult to use at these small apertures, the image would be very dim.

[@jamesjacocks6221]

Hi Joe. I was using Symmar lenses with foil micro apertures between the groups many years ago. The problem with extremely simple optical systems is distortion and falloff, neither of which improve with smaller stops. I am very interested in your foray into this dimension.

[@Joe_VanCleave]

Yea, I don't expect to achieve the same quality image as with more sophisticated optics, but if a simple lens and the appropriate aperture size can improve on the pinhole's image, it would be a good alternative from pure pinhole alone.

[@jamesjacocks6221]

Joe, I found that when using regular view cam optics and home made aperture the critical aperture for semi pinhole effect and near universal focus was f/focal length or f/150 for a six inch lens. That made the aperture 1 mm in every case. Box cameras could be built w/o focus if extreme close focus wasn't needed and the images looked to be between sharp and pinhole. Simplified shooting greatly. Time exposures only but that was what I wanted. Cheers.

[@Joe_VanCleave]

Thank you James!

[@EFD620G]

What effect would a glass magnifying loupe in front of the pinhole cause.

[@Joe_VanCleave]

It can improve the sharpness as compared to just the pinhole. The size of aperture needs to be adjusted to find a reasonably good compromise in quality.

[@tommyjerry3936]

very cool project mr.

[@edcarter9069]

Joe, thanks for a great discussion and an exciting idea. I would love to build one of these systems. Do you know of any means of calculating an f stop for the modified lens or is it strictly a matter of trial and error? Also wondering if there is a means of calculating an optimal distance from the lens or pinhole plane to the film? Thanks again for the interesting discussion!

[@Joe_VanCleave]

The focal ratio should be focal length divided by the pinhole aperture diameter. As for an optimal focal distance, it should be the focal length of the glass lens itself.

[@camilaespinoza4053]

Hi Joe! Thank you very much for this content!! I will like to ask, if you can tell me the exposure times that you used for the photographs. I know it was many years ago, but I'm very interested on trying this method. What was the difference in seconds between the wide open binocular lens and the lens with the 3mm aperture. Thanks again!!

[@Joe_VanCleave]

The difference in exposure time is based strictly on the difference in aperture. The lens has a 150mm focal length and 50mm wide aperture fully open - that's F/3. Stopped down to a 3mm aperture, it's F/50. I took a meter reading this morning, using ISO 12 for paper negatives. At F/3 the exposure time was 1/15 of a second, while at F/50 it was 25 seconds.

[@BeesWaxMinder]

What type of lenses do I need for this? Do they need to be flat on one side? If so should the flat side face the Latent Image?

[@Joe_VanCleave]

Any plano-convex or double-convex lens should work (or even a meniscus), if its focal length is close to that of the camera's. With traditional box cameras using single-element meniscus lenses they often put the concave side toward the subject. With this hybrid pinhole/glass lens it may not matter as much, since the lens will be radically stopped down, closer to a pinhole in size.

[@klausphotobaer5754]

Hello there. As I followed along the video I was thinking about two things. Firstly, the two curves of the diagram look like the " plot " of two mathematical equations ( wich they surely are ). So, by putting in the values of the pinhole / lens , it should be possible to find the optimal values. Ok, I think the math behind it is a bit complicated, but it would be interesting to see the formula. Maybe You know the math behind this ? Would be great if You'd share it. Secondly I thought about how to further minimize the distortions. Would You say that it could be helpful to use a color filter in front of the lens? It would minimize some distortions ( chromatic abberation ) if You narrow the " spectrum " down to fewer wavelenghts. As paper negatives are mostly sensitive to blue colour it would be interesting to see what it looks like if some colors are cut out. I bet they will look like old film, pre " Orthochromatic" so to speak. Last but not least I'd like to thank You for another great and interesting video and the time You've put into it. It is highly appreciated !

[@billhackley3540]

just the slightest hint of a grin on the hittites, levites etc.. I was just this morning boring my wife with the idea of a makeshift lensboard/pinhole conversion on my 4x5. have a fujinon copier lens coming. lots of experiments coming up thanks for all the videos

[@billhackley3540]

surprised given your talent you haven't went down the collodion road

[@Joe_VanCleave]

@@billhackley3540 Eventually!

[@filmlovephotography]

Hello Joe Van Cleave, great videos, great work. Let me ask you, I have a old Kodak Brownie, to make a hybrid pinhole, I must put the diaphragm (pinhole) in front of the lens or inside the camera. Thanks and hug from Portugal.

[@Joe_VanCleave]

Ideally, it depends on the optical design of the lens. But I'd first try it on the outside. If it works, you'll have less lens flare in bright light, and it'll be easier to replace the pinhole with film still loaded in the camera.

[@filmlovephotography]

Thanks Joe Van Cleave, my model is a Kodak brownie model C, meniscus lens. Just only one more question, the pinhole has to be near the lens or it may be a little far?

[@Joe_VanCleave]

As close as you can get. Too far and you will vignette the corners.

[@filmlovephotography]

Joe Van Cleave Thank you very much for all. Keep the good work. I'll keep seeing. Hug

[@IainHC1]

How will the pin hole board work with the glass behind it?

[@Joe_VanCleave]

It will work fine. There are optical differences based on the lens design and distance from pinhole to lens that affect the off-axis abberations and out-of-focus areas. Lots of room to experiment and find the look you want.

[@sonnybeach1953]

Joe, this is off topic, but have you ever showed the people how to build an eclipse viewer out of a cardboard box with a pinhole in it? Solar eclipse will be coming up on 21 Aug 2017.

[@Joe_VanCleave]

Hmm, if I could find it, I'll do a video on my cardboard shipping tube pinhole camera with makeshift view screen that you can use to photograph eclipses with a cell phone or other camera.

[@BobSmith-dx9bj]

Inteserting. I guess it would be impossible because of film sharpness to have a line without any falloff. Thanks make me think!

[@zabtej1645]

No need for the particle nonsense. It still makes sense if you just say waves. But waves are not a thing, are they?