feasability of ultra small aperture cameras

[noeffred]

Hello all!

I'm planing to build myself 2 4x5 pinhole cameras, one for landscapes and one for portraits. The second one is a bit of a problem for me.

What I'd like is a pinhole with a rather longish focal length. Being in large format territory, I was thinking along the lines of 150mm. Now the problem is that I'll end up with an aperture of about 270 which - facturing in the reciprocy failure - would require my subjects to sit still really long, which is something I'm fully aware of.

I've got no experience with this so my happy-go-lucky approach would to get some HP5 Plus 400 for the portrait camera and Fomapan 100 for the landscapes (I quite like that film and it's very cheap here). Is this a sound idea? Is a pinhole with such a large aperture useable for portraits? Is there something I haven't factored in? I suppose someone around here has already built a construct like that and could possibly share some experience?

I ran my plans and combinations through the pinholedesigner and the online tools mrpinhole.com and they check out. Can I just rely an that and go ahead with the build?

I hope someone can help me out with this

 

[Rick A]

Heck yes. The bellows camera is 70-170mm the other is 55mm.

 

[David William White]

I had a box pinhole that I made (for 8x10 paper) that was about 'normal' that I used for a few portraits. The only thing that comes to mind is aiming & framing your sitter. Other than that, have fun!

 

[noeffred]

Gentlemen, thank you very much, I'm off to the workshop!

 

[nickandre]

And you don't have to focus.

 

[Joe VanCleave]

1. You should figure out how to sit the subject in bright daylight, while using screens and/or reflectors to take some of the intensity out of the harsh sun and also fill in the shadows a bit; this will reduce your exposure times (the bright sun, that is) while working to improve the contrast and tonal range. I would consider lighting to be at least as difficult as the camera building; perhaps the biggest single challenge.

2. You'll need some portrait-appropriate backdrop or background, keeping in mind that whatever is behind the subject will be equally sharp as the subject themselves. And, keeping in mind point #1 about daylight exposures, this means rigging up some backdrop out of doors.

3. Wind and/or breezes may come in to play, perhaps moving the subject's hair a bit; this is just part of the fun of outdoor pinhole portraits.

4. The shorter the focal length, the smaller the focal ratio; you may thus want to consider an ultra-wide angle, short f.l. 4x5 design, whereby with sub-f150 apertures you'd reduce the exposure time even more. Shoot whole-body portraits with this type of wide-angle camera, within an existing environment (i.e. it'd be too hard to make such a wide backdrop, just work with the surrounding environment).

5. Fuji Acros for B/W has much less reciprocity failure, giving you reduced exposure times for pinhole.

~Joe