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I recently made my first pinhole camera and started taking photos with it. It's a Illy coffe can camera with a 0.35 mm pinhole aperture. I am using an old pack of Ilfobrom FB IB2 photo paper. It's 17.8 x 24 cm so it fits nicely inside if I cut it to three strips of 17.8 x 8 cm. Developing process is:

  1. Ilford PQ Universal 1+9. It takes about 20 - 30 seconds for the images to appear.

  2. Home made stop bath. I use a 7 g/L citric acid solution producing a ~2.3 pH solution which is close to the commercial Ilfostop solution. I leave the photos inside for about 10 seconds.

  3. Ilford Rapid Fixer 1+9. I leave the photos inside for 2 minutes.

  4. Washing the photos in the sink, periodically changing the water.

Some photos will turn out with a strange cloudy overlay. For example: pinhole photo This was taken on a sunny day. Exposure was 50 seconds.

What is causing the cloudy overlay and how to prevent it?

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    \$\begingroup\$ Have you tried developing an unexposed sheet of paper to see whether the problem is with the camera or the processing? \$\endgroup\$
    – John
    Commented Jun 21, 2016 at 12:40
  • \$\begingroup\$ Thanks for your comment. Close to it: I severely underexposed one photo (night time, indoors), and it shows no visible clouding after developing. There are also correctly-exposed photos with no visible clouding. \$\endgroup\$
    – shrx
    Commented Jun 21, 2016 at 12:51
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    \$\begingroup\$ Might be light leaks, or chemical contamination of paper (e.g. touched by hands wet with developer). Nice photo, though, even with streaks! \$\endgroup\$
    – DrMoishe Pippik
    Commented Jun 21, 2016 at 13:26
  • \$\begingroup\$ @DrMoishePippik thanks, I also tried to correct the perspective with Hugin: i.sstatic.net/BP2bZ.jpg \$\endgroup\$
    – shrx
    Commented Jun 21, 2016 at 15:30

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If you remove the paper from the developer after 20 seconds, the clouding could be caused by uneven development. Look at the recommended development time for the paper and the developer and adjust exposure accordingly.

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  • \$\begingroup\$ I have lowered the exposure to 40 seconds and there have been no photos with this effect in my second batch except one - a very bright scene taken on the sea shore during a bright sunny day. So it seems that overexposure combined with too fast development is the cause of the issue. \$\endgroup\$
    – shrx
    Commented Jul 1, 2016 at 20:19
  • \$\begingroup\$ Adjust the exposure to meet the recommended development time per paper/developer manufacturer if possible. You will most likely get better looking results, for example deeper blacks. \$\endgroup\$
    – MirekE
    Commented Jul 1, 2016 at 20:32
  • \$\begingroup\$ Yeah the second batch took about a minute to develop and the photos look much nicer. \$\endgroup\$
    – shrx
    Commented Jul 1, 2016 at 20:38
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MirekE is spot on -- Try to adjust exposure to allow a minimum of 90 seconds developing time.

Your stop bath will work OK -- best for simplicity to switch to 15ml of ordinary vinegar per liter.

Extend your fix time to 4 minutes.

Do test a strip of unexposed paper. If you are working via a safelight, place a strip of paper emulsion up in your work area. Lay a coin or two on the paper. Allow this paper to remain for 10 minutes. Now develop the this test strip. If an image of the circular coins is seen after 90 seconds of developing, the safelight is not safe.

Best of luck!

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  • \$\begingroup\$ Good tips, I will make sure to do the safe light test. \$\endgroup\$
    – shrx
    Commented Jun 21, 2016 at 18:50
  • \$\begingroup\$ Using vinegar will give the prints an odour that might be hard to neutralize. \$\endgroup\$
    – Stan
    Commented Jun 23, 2016 at 16:08
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    \$\begingroup\$ Vinegar (acetic acid) diluted is used as the stop bath and is an ingredient of the fix bath. The developer is generally alkaline, acetic acid neutralizes. The smell of vinegar is the perfume of the darkroom. \$\endgroup\$
    – Alan Marcus
    Commented Jun 24, 2016 at 16:31
  • \$\begingroup\$ I did the tests - unexposed paper does not appear to have this cloudy effect when developed. Safelight also doesn't seem to cause any exposure of the paper. \$\endgroup\$
    – shrx
    Commented Jul 1, 2016 at 20:27

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