Another 4x5 pinhole

BetterSense · 06-23-2009, 09:07 AM

I didn't have any of them fancy film holders, so this one follows the design of my 8x10...the film sits in the back, and the front slides into the back holding the film flat. Reloading is by changing bag, but it should be a lot more convenient with the small size! It's really quite cute.

I stole CuS's idea of using a shutter out of an old camera. I stole the shutter assembly out of my Jiffy Kodak 620 camera, which has a "T" setting. I just don't know if the shutter blade seals well enough around the pinhole, since you can see an air gap when it is shut. I made my first exposure on the way to work this morning, but I don't know if it's going to work. I made the pinhole pretty small, it's about .35 mm and the focal length is like 60mm

Apologies for the quality of the image, it was the only one I had at work since it was attached to an email to my friend.

bsdunek · 06-23-2009, 11:40 AM

If I'm calculating correctly, that's f 171 - not small at all. My home made pinhole for my Mamiya Press comes out to f 207, and the photos aren't very sharp. I'm going to make a new one somewhere between f 250 and f 300.
That said, try yours before you change anything - it may work fine.

CuS · 06-23-2009, 12:23 PM

0.35mm pinhole would need about a 77mm focal length - roughly - try it and see.

I have my 0.3mm pinhole at 50mm but it should be a 57mm instead - i will try that tonight - here are some shots with "Ned", btw (not sure if I shared these yet):

http://www.flickr.com/photos/colusit...7620033768138/

Cant wait to see your stuff!

I guess the smaller the pinhole (to a point), the sharper the image.

I wonder what the best size is?

BetterSense · 06-23-2009, 01:33 PM

Well it sure seemed small compared to the .5mm in my 8x10. I had a hard time making one small enough with my typical sewing needles. I heard that acupuncture needles were better but I don't know where to get any.

BetterSense · 06-23-2009, 01:49 PM

Awesome; I just came home and developed my two shots. I forgot to mark which was which, though. They were shots of a building and I did one at about 9am for 15 seconds, and then did another one about 11:30am for 5s. They both look similar but one is slightly more dense and contrastier. I have some light leakage around the edges which I think I can fix with felt. I used Arista EDU ultra 200 and developed in D76 1+1 for about 6 minutes

CuS · 06-23-2009, 01:53 PM

post dem images - i wanna see!

BetterSense · 06-23-2009, 03:07 PM

Well I left them hanging up to dry. I developed them during lunch.

I don't have a LF scanner so I will have to make contact prints and scan those tonight

BetterSense · 06-23-2009, 05:57 PM

http://i109.photobucket.com/albums/n...nholenserl.jpg

It works, but I'll have to approach it more seriously. Right now it doesn't seem like it's as sharp as my big camera.

DWThomas · 06-23-2009, 06:44 PM

Looking good. APUG should have a big turnout for WPPD 2010!

DaveT

CuS · 06-23-2009, 08:53 PM

Quote:

Originally Posted by BetterSense

http://i109.photobucket.com/albums/n...nholenserl.jpg

It works, but I'll have to approach it more seriously. Right now it doesn't seem like it's as sharp as my big camera.

Mine are a bit blurry too - maybe a mismatch b/t pinhole size and focal length? Since its hard to make a pinhole for a set camera, maybe make a good pinhole and build the camera around it - or buy one of those fancy-dancy laser-cut pinholes - whats the fun in that though?