Pinhole macro (does this count as a "Lens" question?!)

[Sharon]

Hello, I hope I'm not posting this in a drastically incorrect place, as I wasn't sure where LF pinhole photography fit :) .

I'm wondering if anyone has any experience doing pinhole macro photography, which they could share in terms of equipment, technique and overall feasibility.

I've been interested in fairly extreme macro photography for awhile now but have found it overall extremely frustrating. I started with medium format but graduated to 4x5 with the prospect of getting in even closer. While I've had some successes, I've found the whole thing extremely difficult in terms of the precision of setup required, and particularly the sensitivity to very small changes of position that occur from things like putting in film holders, moving the focusing cloth, the flapping wings of nearby butterflies, etc. ;) ...

My partner suggested I try pinhole, given that the setup is easier and more robust, the small size of the aperture means that I don't have to worry so much about the precision of my focal plane, and the lack of ground glass at the back means I have to let go of my control-freakishness about trying to perfect the composition (and then often being disappointed when it's changed slightly from what I thought it was).

We've tried some exposures, but our pinhole camera is a wide-angle, 75mm focal length camera with a pinhole optimised to focus at infinity. This means that very close objects appear extremely soft, not sharp at all. We contact-print, and I like to print directly from 4x5 negatives without enlarging, so my negatives don't need to be razor-sharp; but the lack of sharpness with our pinhole for near subjects it pretty extreme and not really usable.

We were wondering about trying to get a long focal length camera (on the order of 225mm focal length) with a pinhole optimised for objects about 4-5cm away rather than optimised for infinity. Does anyone know if this is do-able?

Thanks in advance for your thoughts :) ,
Sharon

[Dan Fromm]

If you want poor image quality, go for it. Here are the relevant magic formulae:

effective aperture = aperture set * (magnification + 1)

diffraction limit (resolution in lp/mm at low contrast) is approximately 1500/(effective aperture)

Shooting with a pinhole guarantees soft images. Shooting closeup with a pinhole guarantees completely unusable images.

Don't take my word for it, burn some film.

[Sharon]

Thanks Dan. Soft images are no problem--they don't need to be razor sharp, particularly if they're not being enlarged. But I suppose the point is that using a longer focal length camera, it can still be macro without being close-up as such. Even our wide-angle pinhole produces good images at 4-5cm away--so if the focal length were longer, and the pinhole were optimised for a distance like 4-5cm rather than infinity, we were hoping to get somewhat less soft images that are still decently enlarged.

I take it this hasn't been your experience though ;) ?

[Tim Meisburger]

I don't recall seeing any optimization for subject distance. In everything I read its always been "optimize pinhole size for focal length and everything will be in focus". Why not mount the pinhole on your 4x5 and give it a try that way? Make two or three different size pinhole and compare shots of the same subject. That should give you a direction. If you make an extra large pinhole you can also swap that in for composition on the ground glass before replacing with the shooting pinhole.


In other words, I know nothing. But am looking forward to the results of your experiments!

[Ted R]

There's a pinhole forum over at APUG.........

[Dan Fromm]

Sharon, your concept of good is very different from mine. But seriously, just take a couple of shots with a pinhole on y'r 4x5 camera with 225 mm extension and see whether the results please you. 225 mm will give you lots of working distance. But since with pinholes focal length = extension I don't see how it will give you high magnification. Unless, that is, I completely misunderstand pinholes. This is very possible, not my usual territory.

A question. What do you mean by "fairly extreme macro photography?" Specifically, what range of magnifications?

[Jim Jones]

For maximum sharpness, pinhole photography favors wide angle cameras over long focal length cameras. Trying to "focus" a pinhole camera for micro-photography gives results rather like enlarging pinhole images. Reducing the pinhole diameter should help up to a point. There is a formula for calculating that reduction, but I can't find it at the moment. The digital age permits one to quickly do rough testing with little cost. A variety of pinholes and a bellows on a DSLR facilitates such testing. Jon Grepstadt has revised his website at https://jongrepstad.com/. The previous version of that site had additional information, and is archived at http://photo.net/learn/pinhole/pinhole. Many of the links there may no longer be valid. Jon has served the pinhole community well over many years.

[scheinfluger_77]

I've not tried any of these, but you might try the calculator located here, http://pinhole.stanford.edu/phcalc3.htm. It has controls for optimizing for wavelength as well as reproduction ratio. You might find that sharpness is less of an issue than getting enough light on your subject due to the high f number.

[Vaughn]

I have used my 4x5 as a pinhole camera -- I mean, everything you want is already there! Lol! Adjustable pinhole-to-film distance, film back. Stick a lens on it perhaps just to check that you have it pointed in the right direction.

And you are bound to do better than I! My Boys in the Backyard: hand made pinhole of undetermined size, Gowland 4x5, Type55 (scanned contact prints from the negatives).

Sure would be nice having something like Type55 (other instant film) for feedback for macros, though! Good Luck!

[NedL]

For maximum sharpness, pinhole photography favors wide angle cameras over long focal length cameras. Trying to "focus" a pinhole camera for micro-photography gives results rather like enlarging pinhole images. Reducing the pinhole diameter should help up to a point. There is a formula for calculating that reduction, but I can't find it at the moment. The digital age permits one to quickly do rough testing with little cost. A variety of pinholes and a bellows on a DSLR facilitates such testing. Jon Grepstadt has revised his website at https://jongrepstad.com/. The previous version of that site had additional information, and is archived at http://photo.net/learn/pinhole/pinhole. Many of the links there may no longer be valid. Jon has served the pinhole community well over many years.
Hi Jim, I think you are thinking of the Prober-Wellman formula (http://www.huecandela.com/hue-x/pin-pdf/Prober-%20Wellman.pdf), which I'm pretty sure I learned about from you! It works, I've used it. I have a photograph somewhere of the inner clockwork of a small pocket watch on 5x7 paper and it is quite sharp ( for pinhole! ). It was made with a 0.15mm pinhole in a camera with a "focal length" of about 4 inches. Lighting is a challenge since the object is so close to the pinhole camera.

[Sharon]

Hi all,

Thanks very much for your replies--a lot to think about :) . I've seen some information that talks about optimising pinholes for a particular focal length and also some different information that talks about optimising pinholes for the pinhole-to-subject distance, which is why I was asking real people with real experience if it is possible, or rather perhaps scientifically meaningful, to optimise a pinhole for a particular distance (either as a stand-alone question or in addition to being optimised for a focal length). Light will of course be an issue, but my plan is to bring along a sketch pad and pencils, or a good book, or some music to practice, to pass the time during hour-long exposures ;) .

In the meantime, thank you for links to websites and calculators, and I have a plan brewing to see if I can do some experimentation digitally.

Thanks again,
Sharon

[mdarnton]

You might find this site more useful:
http://www.f295.org/main/forum.php

[Sharon]

Hi again all,

Thanks again for your suggestions and pointing me toward some very useful links. I've surprised myself with some success! I bought a set of pinholes from pinholeresource.com and mounted a couple of them on lensboards, then used them with our 4x5 Arca. I tried two setups, one at a focal length of about 200mm and one at about 400mm. In bright sunlight (through the window) I got reasonable exposure times (5-30 min, though as you can see, if I've attached the files correctly, I still had some under-exposure with one setup). Particularly with the 400mm focal length, I was getting good magnification of around 5x--not pin-sharp, of course, but I'm really interested in being able to see detail (which I can) rather than maximising sharpness.

151093151094

I'm keen to try getting closer in with the 400mm focal length, but I'm finding that as I move it closer to the subject, the large camera throws a lot of shadow on the subject, pushing the exposure times to the ridiculous. We have some ideas about how to combat this--namely, constructing a tapered camera (we're thinking of adapting a traffic cone, for starters :) ) and learning how to use a flash.

Anyway, thanks again--I'm pleasantly surprised that I seem to be getting somewhere! If anyone is interested in updates, let me know and I can keep posting :) .

Best wishes,
Sharon

[Tin Can]

Cool keep posting results! :)

Your posts sent me to strange pinhole lands. Such as Electron Microscopes that use Pinhole, LF film and Gas Burst Development.

[stawastawa]

Yes keep updating!

[Sharon]

Well, I've built myself a camera out of our old Arca 4x5 rear standard and a traffic cone...photos attached. I'm getting upwards of 20x magnification with good detail, I think (using FP4 and a flash).

151566151567

Next steps are getting rid of internal reflection in the camera and seeing how far back I can move it from my subject while still getting good detail (because the fewer times I need to change the pinhole size, probably the better). Also probably moving to HP5 rather than FP4 so I don't need quite so many passes with the flash, but we'll see...

Thanks for your interest :) !

Sharon