Spots like a dark sun - Rollei RXP 25

[mooresean68]

Hey All,

Using SP-445 tank and no issues to date until I experimented with some Rollei RXP iso25 developed in Adox Adonal. The exposures were so so but of real interest are these very circular dark spots with halos.

I haven't found these kinds of spots on ilford HP4, ilford delta, or kodak tri-x developed in the same tanks (and developer). Sure there's a lot of hairs and dust but nothing like these dark suns.



Any ideas what would cause them?

Thanks
-Sean

[koraks]

My bet wouldbe on either tiny water drops on the film during storage or in the camera, or small flecks of a chemical that found their way onto the film surface. Water seems a bit more likely. But this is a wild guess.

[Pat Kearns]

I would say that these were caused by air bells on the film after you poured in the developer. You need to give the tank several hard bangs to the bottom immediately after the developer is poured in to dislodge the air bells. If the tanks are plastic then fold a towel and bang the bottom on the folded towel on the counter to keep from cracking the tank. Another way to prevent air bells is to presoak the film.

[dsphotog]

Second the air bubbles

[Drew Wiley]

Sometimes a tiny mineral speck from unfiltered water behaves like a seed, around which either an air bell or chemical halo will form.

[LabRat]

Skin sweat while loading/unloading film???

Steve K

[mooresean68]

Thanks everyone, I'm hedging toward the air bubbles/bells. I use distilled water for the chemicals. Could some film types or brands be more susceptible to trapping air than others? This was my first time with the Rollei and found the film stock is really thin, like half the thickness of ilford or kodak.

Thanks
-Sean

[Drew Wiley]

Do you tap the bottom of the tank when beginning each step of development to shake free any potential air bubbles? Sometimes the quality control of the film does make a difference. For example, when Fotochemika was nearing the end, they were having dust issues on the coating line. I liked Efke 25 roll film; but the last batches would have little bits of grit embedded in the emulsion, not only ruining those particular frame, but attracting and holding little halos even harder to spot out from the print. I almost never get that issue with major brand films like Ilford, Kodak, or Fuji. The Rollei film you mention does not strike me as equally well coated, though I have never personally gotten the specific issue you show.

[interneg]

For example, when Fotochemika was nearing the end, they were having dust issues on the coating line. I liked Efke 25 roll film; but the last batches would have little bits of grit embedded in the emulsion, not only ruining those particular frame, but attracting and holding little halos even harder to spot out from the print.

It was worse than that on the faster emulsions - and it was because their emulsion plant was getting sufficiently unreliable that it wasn't evenly controlling heat during the melting step (I think) prior to finals before coating - which seemed to cause the grain to form visible & opaque clumps. Very annoying because I liked the spectral sensitivity & overall slightly imperfect character of the material.

The Rollei 25 film is Agfa Aviphot 80s with a more realistic sea-level EI on the box.

[mooresean68]

Normally I fill the tank and start agitation for the first 60 seconds then tap before and after each agitation after that which is why I'm leaning toward the air bubbles. I'll have to work that initial tap into my routine.

Thanks
-Sean