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- Mar 28, 2008
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I rolled up a couple of cans of AP 400 that I bought last year a couple of weeks ago and got around to developing some of the film from a recent trip on Sunday. I was pretty surprised to see that it has quite high base + fog. I developed a single roll along with a roll of Tri-X in the same tank using the same chemistry and the AP 400 base looked noticeably darker. I did some measurements with my DA Enlarger meter last night using it as a projection densitometer and here is what I found:
The Tri-X base + fog was 0.378. The AP 400 was 0.627. I measured some AP 400 from earlier last year and found that came in at 0.441.
I then tried developing some unexpected film. From the same lot:
- Exposed AP 400 leader. This was right around 0.3.
- Unexposed AP 400. This was right around 0.24.
From a different lot of AP 400.
- Unexposed AP 400. ~0.24.
I then measured some unexposed Tri-X. It measured ~0.21.
I have 10 other tins of 100 foot AP 400 in my fridge that I just bought. I'll roll up a sample of that tomorrow and shoot & develop and see what I get.
What would be normal for the film? How harmful is this high fog?
At this point it looks like I have 2 entire tins which are not all that usable which is pretty disappointing.
The Tri-X base + fog was 0.378. The AP 400 was 0.627. I measured some AP 400 from earlier last year and found that came in at 0.441.
I then tried developing some unexpected film. From the same lot:
- Exposed AP 400 leader. This was right around 0.3.
- Unexposed AP 400. This was right around 0.24.
From a different lot of AP 400.
- Unexposed AP 400. ~0.24.
I then measured some unexposed Tri-X. It measured ~0.21.
I have 10 other tins of 100 foot AP 400 in my fridge that I just bought. I'll roll up a sample of that tomorrow and shoot & develop and see what I get.
What would be normal for the film? How harmful is this high fog?
At this point it looks like I have 2 entire tins which are not all that usable which is pretty disappointing.
Also, I later spooled up some double X & Tri-X and it has no fogging. Furthermore, if my darkroom had a leak you'd expect all of the film I developed at the same time as the AP 400 (I spooled up and prepared a roll of Legacy Pro 100, three rolls of Double X, one roll of Tri-X and 2 rolls of AP 400 at the same time) to all be similarly fogged and they are not.
I developed a separate roll of film from the same bulk roll by itself in a tank and it had exactly the same issue.