It wasn't a cake walk, but I'm sure it sounds a lot more complicated than it really is, at least as far as my work was concerned. You lost me pretty quickly too-- Cash On Delivery? Table of Contents? I should have paid more attention in my chemistry courses, apparently.
Originally Posted by Kirk Keyes
I'll take another crack at the Vuescan densitometer; I did most of what you described, but I didn't clear my settings so maybe that's the issue (Vuescan is so finicky sometimes). Either that, or maybe it isn't supported by all scanners. Thanks for the tips, though.
Sorry - Chemical Oxygen Demand and Total Organic Carbon - both tests used to predict how much oxygen will be consumed by waste water when released into natural waters, i.e. rivers or lakes...
Originally Posted by Scruff McGruff
For up from the ashes, up from the ashes, grow the roses of success!
You're getting real hung up with a difference in base density between 35mm and 120. There is a difference in base density, I'm at work and don't have access to my readings, but 35mm base stock is dyed for anti-halation properties
Originally Posted by Scruff McGruff
No problem, I was just joking around a bit. Neat stuff, though!
Thanks for that bit of info-- I asked in a previous post if there were differences between the 135 and 120 film base/emulsion, so I appreciate you chiming in!
Just from memory, 120 base density around 0.10. 35mm triX around 0.25, so quite abit of difference. Some 35mm bases are very clear but have problems with light piping-such as the micro films.
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I just ran across this thread. I'm having the same problem. I've been through many, but not all of the checks you have done to eliminate causes. It's not my camera or scanner, I had ruled them out. It looks as if you have done exhaustive testing over a long period of time. In the same period of time I have only shot & developed maybe 5 rolls of B&W but have seen the problem on all. I will be trying some of the suggestions here and continuing to follow the thread. If I run across a solution I will post.
How are you rinsing and drying the film?
Is it possible there's reticulation from a temperature shock due to running water into the tank as your rinse method? Some of the earlier images looked a bit like reticulation but it's not easy for me to be positive.
Just to be sure, are you using one of the vacuum column 'archival' film reel washers fed by tap water? Or are you using the Ilford three step wash method, preferably with DW?
When you dry the film do you hang it at an angle so the water can run down one edge or straight down so it can run down the entire film surface and both edges?
Either way are you applying a weight at the free end to keep the film straightened out during the process? It can "pool" either way and change the apparent density of the edges, btdt.
Are you using a squeegee, your fingers, or a sponge to get most of the water off the film after rinsing prior to hanging to dry? I'm assuming you're not using a DSA/Senrac or the like for forced air drying while the film's still on the reel, right?
Got a ceiling fan running or are you near an air conditioning vent that might be changing the temp of the film while it's still wet? Long shot I know but it's worth asking I think.
Some emulsions are more prone to reticulation than others and it's not absolutely positive that the Arista is absolutely identical to Kodak Tri-X, at least not to me anyway for what that's worth. Apparent base+fog can increase if the film gets reticulated, maybe you could provide a magnified scan of some of the worse bits of film to see if there's a reticulated pattern present.