Different than expected results with FP4 @ 125 in XTOL 1:1

[Doremus Scudder]

I just took a quick look at the characteristic curves for FP-4Plus and HP-5Plus in the Ilford literature; they don't look all that different to me except that HP-5 has a bit more of a shoulder. The curves in the Ilford tech sheets weren't all that detailed, however.

Medium speed films like FP-4 are inherently more contrasty than faster films. The usual initial challenge with these is finding a developing time that tames the overall contrast yet still gives you the local contrast/separation you want. The impression of "muddy" and simultaneously "too contrasty" is a bit of a contradiction in terms, but may relate to differences in curve shape, e.g., mid-tone separation is not what you want, but the highlights are right or even too high. Things like this are characteristics of particular films and can't be changed very easily. A staining developer might tame highlights somewhat in a case like this (not sure if that's really your actual situation) or you can just move on to a film you like better.

It may be interesting for you to make the same image with both films a time or two and really compare how the distribution of tonalities are. For me, it's a valuable exercise. When I'm learning a new film, I load holders back-to-back with an old favorite (usually 320Tri-X) and the new film and make two exposures of the same scene for a while. Sometimes I like the new film, sometimes I don't.

Best,

Doremus

[esearing]

I use a Sekonic 758 with LF. I was looking for generally an actual grey subject (e.g. a grey rock) that was roughly middle grey then look at values on either side, tending to side with a bit of overexposure when comparing multiple greys. I would also often compare that to the incident reading.

Use the meters Avg function having measured brightest and darkest areas with texture. It will visually show you the range of stops and relation to middle(Zone 5) and help you visualize where to place a mid-tone object. I read every scene in EVs and use a 3x5 card to determine where to place those EV values along with other exposure and processing notes. In a high contrast situation it helps me see what will be pure black or white based on where I choose to place the lowest EV values, so then I can expand or contract in development. If in doubt, I make two identical exposures at the scene, develop the first one evaluate it, and then make changes for the second.

[m00dawg]

Doremus you're right on the money with what I'll try next time. I probably won't be doing any backpacking trips soon but I have some spots I can take some landscapes that might be somewhat similar to what I shot last week so I can try various films. I kinda want to grab up some TMX to try but fairly expensive in sheet form. I already have HP5 and Delta so I will for sure compare those to FP4. I might also compare FP4 in different developers (XTOL and ID11) to see what those differences are.

Admittedly I forgot about the 758 could do averaging :P I've used it before but yeah sure didn't use it for the trip. Doh! A pre-made note card is also rather clever! I do that when filing my negatives (I wrote a webapp to help me make info sheets to file with my negatives, though it's mostly for roll film) but didn't think of that while on the go. Good idea!

All told, thanks for the advice everyone! Got a lot to think about and try for the next time I'm out and about with my 4x5 (hopefully soon)!

[Eric Woodbury]

Even with XTOL, it is hard to get full box speed from FP4+. For 35mm, where you may care about 'least grain', give it another 1/2 stop under normal conditions. With LF, unless you are going to enlarge something to wall size, absolute smallest grain doesn't really matter. Give LF extra light. Don't worry about placing Zone 2.5 exactly, but get Zone 4 set properly. Rate your film at 64 ISO for LF.

Ilford films tend to have more green sensitivity than the yellow box.

Finally, if you are in the mountains and at higher elevations on a nice clear day, you are getting a lot more blue light, especially in the shadows. Just because the atmosphere is thinner and allowing more blue to pass. This can fowl things up in several ways. Most light meters don't see blue light very well. This would cause over-exposure. The human eye doesn't see blue light very well, which leads to improper interpretation of values. Finally, B&W film sees blue light very well, further confusing exposure calculations. Adding any color filtration or polarizer, is further confusion in calculations (not necessarily good or bad). Bottom line is to make a couple extra exposures until you become fully calibrated to such light.

Happy snapping. EW

[m00dawg]

Oh man actually the altitude probably did play a factor. Trailhead was I think maybe 8500 and our max height was 11,000 if I'm not mistaken (I probably am). Definitely at altitude though and I should've realized that would have been a factor given how beautifully blue the sky was compared to sea level. Really good point!

I've also thought about pulling FP4 down a bit as well just to see what sort of look I get so yep I think that's worth a shot. Are you saying rate at 64 but develop normally or compensate in dev? (Massive Dev has pulled ISO ratings for XTOL I could use).

[Eric Woodbury]

Massive Dev chart I find pretty good.

I won't tell you what to do, but personally, I would rate at 64 ASA for normal contrast. Develop as per Massive Dev. For an exposure, I would measure and place zone IV. I do this because I don't usually care much about the zones lower and my eye is calibrated at Zone IV. That said, if I have a critical Zone I or II, then I'd measure there and place appropriately.