Film processing artifact

[md2008]

Hi,

Out of curiosity, I was just wondering if anyone knows what could be causing the processing artifact shown in the photo below, top left corner (mottling). It only happens at the one store I drop off film and is most noticeable on light, even toned areas such as sky/cloud photos.

You can see the same artifact here, but much more subtle, again top left corner on the white panel.

The problem is, this store charges $2.99 per roll for developing and scan to CD. Everywhere else I've found (which don't have this artifact) costs $15.00 per roll for developing and scan to CD. I guess you get what you pay for... If anyone knows of anywhere else in Toronto you can get cheap C-41 done, please post or PM.

Thanks

 

[Chriscrawfordphoto]

Its reticulation, caused by rapid temperature change. All the chemicals used in processing must be exactly the same temperature. Modern films are usually ok if the chemicals are different by a couple degrees, but if its a big difference then going from one chemical to the next will cause the problem you see.

 

[ZorkiKat]

AFAIK, colour film emulsions are more robust, theyt can withstand about, or more than plus/minus 5 degrees (Celsius) either way. I've hand-processed C41 film with the wash, bleach, and fix temps wander far off (more like 28 C from the dev temp of 38 C) the 'official' temps, and got no reticulation. Colour film emulsions are already prehardened to withstand high temperatures too. In an automated processor, the temps don't usually wander too far.

The crazed/cracked patterns of reticulation is also usually much smaller. If the first photo above is full frame, or close to it, the crackling won't be obvious. The magnification has to be greater, to an extent that the grain pattern of the image is almost visible.

What I see here could be a pattern left by a stabilizing/final rinse bath which frothed too much. The negative can be examined from a steep angle to see if such marks are existent on the surfaces- usually on the base side. This could also be from dirty processor rollers which may impart strange patterns on the film which passed through them.

 

[nimcod]

i would be tempted to say it looks like over digital ice + sharpening artefacts, examining and/or re-scanning the negs would really be the way to tell if it seems to be on the neg itself.