feasability of ultra small aperture cameras
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