macro photography with a pinhole?

[flsurf]

Just out of couriosity I was wondering if it was possible to construct a pinhole camera that would be for taking macro photographs, I took a few pictures of my beehive using a 25mm focal length camera 120 film, even at a distance of 4 inches the result was wide but image not as enlarged as I would have thought.

focal length?
longer?
fl

 

[keithwms]

Yes, you can do it.

But I think if you draw a ray diagram you may see a problem if you use a pinhole, you bring it very close to your subject, and your film sensitivity curve isn't narrow. For one thing the material in which the hole is made would need to be very thin, or you'll get some odd vignetting. But also remember that pinhole is kind of the opposite of a modern apo/uld/ED lens... a pinhole does a very poor job of focusing different wavelengths to the same plane. As the subject gets closer to the pinhole, that issue should get more noticeable: rays containing all the colours will need to approach the pinhole from more extreme angles. Hence my suggestion to use a film with a narrow sensitivity curve... it'd be best if it were sensitive to a single wavelength

But try what you have in mind, who knows, maybe it will work for you. Experimentation is good!

Another thought would be to shoot several exposures with slightly different focus, and stack those. Or get a lens that stops down more!

 

[Jim Jones]

For some information on pinhole macro photography, see Dead Link Removed. The last page has a formula for determining pinhole diameter for macro photography.

 

[BradJudy]

I did a little bit of macro pinhole (defining macro as 1:1 or greater). Here are a couple of pictures using my 25mm 120 film pinhole with objects at 25mm distance from the aperture. Due to the tight conditions, I used objects that I could backlight instead of front lighting:





Macro math on a pinhole is simple - for 1:1, the focal length is equal to the distance to the object.

 

[timllowe]

This would suggest that, at least for b/w film, the addition of a color filter would improve the sharpness of the image.

Am I right?

 

[Jim Jones]

This would suggest that, at least for b/w film, the addition of a color filter would improve the sharpness of the image.

Am I right?

Based on my experience, there is a modest improvement when matching the effective film color response to the pinhole diameter. However, it's hardly worth doing for casual photography. The blur on panchromatic film caused by the chromatic aberration in a pinhole should slightly resemble the softness that is treasured in some portrait lenses. The blur inherent in pinhole photography is more prominent.

 

[timllowe]

Thanks. I was thinking specifically about macro photography with a pinhole where some here have suggested that there is more of an effect from chromatic aberration.

I've not tried it which I suppose I should just do.

 

[ibrahimm]

Nice info