Ilford FP4+ users: what ISO?

[Harley Goldman]

I am curious what you rate this film at for general use and normal development. I have done a bit of research and I have seen it range from 50 to 400.

[Drew Wiley]

I have always used 50, both with ordinary developers and pyro. This seems to kick the
film off the toe onto the straight-line section while still leaving plenty of room at the
other end of the curve.

[BrianShaw]

Believe it or not... 125.

[eddie]

Believe it or not... 125.

yup

[Derek Kennedy]

yup

Me three! (125)

[John Bowen]

Harley,

The variables that impact an individual's film speed rating include, but are certainly not limited to:

Shutter speed (Is your shutter accurate?)
Exposure Meter (is your meter accurate/linear?)
Lens flare
Temperature of developer
contaminates in your H2O (like iron)

The only way to really know what YOUR speed for FP4+ is, is with a film speed test.

Bruce Barlow's CD Book "Finely Focused" outlines the tests and provides the tools so you won't need a densitometer to determine your personal film speed.

www.circleofthesunproductions.com

My personal film speed for FP4+ is 365,438 but then my shutter speed for 1/15 is actually something like 5 minutes :-) :-) :-) I wouldn't suggest anyone use my film speed!

[Michael Alpert]

In 5x7, I usually rate it at 60. This way I never miss shadow detail; and I still have room to rate it at a slightly higher speed, if needed.

I switch to HP-5 (rated at 240 or 320) when a faster film is called for.

[Kevin Crisp]

125 from testing.

[Lenny Eiger]

That someone tested it at 125 or anything else for their purposes is entirely meaningless. I also tested it and use the film at 80. Altho' I chose Delta lately instead - for my needs.

Here's how you know. You look at the film and see how much detail you have in the shadows. Then you decide if that's plenty or you need a little more. I like a bit more than the manufacturers' usually come up with. that's why my number is lower. Looking at your images on your site you let things go to black much more than I would so I think you might be just fine at the 125.

If it makes the kind of print you want, then its right.

Lenny

[phil sweeney]

50 for ABC pyro, 100 for pyrocat HD, 80 HC110

[Bill Kumpf]

I used Bruce Barlow's "Finely Focused" method and, for me, FP-4 tested 125 with PMK. Buy his CD. It covers a lot more than film speed.

[Sal Santamaura]

That someone tested it at 125 or anything else for their purposes is entirely meaningless...Only if that someone didn't completely specify all aspects of their test and/or the reader doesn't want to use the same protocol. :)

My rating for sheets of FP4 Plus, metered with a Zone VI-modified Pentax digital spot meter, exposed using a calibrated shutter, developed in a Jobo 3005 Expert Drum on a CPP-2 at approximately 46 rpm ("F" setting with the latest rotation motor), after a 5-minute distilled water prewash, for 8 minutes 30 seconds in Perceptol 1:1 -- 250ml stock per 80 square inches of film -- at 75 degrees F, then measuring 0.1 above film base + fog using a calibrated densitometer, is EI 160. This results in a Contrast Index of 0.50.

I shoot it at EI 125. :) :)

[mandoman7]

I'll 2nd what Lenny suggests. That other people's dev times are a starting point only.

Sure, you can get close to what you want, but you won't really know if you're getting the best results, or the ones that suit your tastes better, without establishing a testing routine. Its part of developing your craft; getting to know the differences in the appearance that different treatments will produce.

You might want to guarantee shadow density as Lenny advises, or you might prefer to let the blacks go a little more and kind of feather those density edges because you are intrigued by shadows. If you have a handle on how it works, you can use the tools to support your vision. Preachy, I guess, but I'm feeling a little old today...

[Jim Fitzgerald]

Pyrocat-HD and shot at box speed. Great neg's.

Jim

[Lenny Eiger]

Only if that someone didn't completely specify all aspects of their test and/or the reader doesn't want to use the same protocol. :)


Sal,

Nicely done. However, you failed to include the most important point. What kind of shadow detail do you like in your prints. Of course, you also have to specify what kind of printing, the paper, developer or inkjet and what set of inks. Then again, even after all that, there is no standard for comparing shadow detail on a print. It's very subjective. Did Ansel have shadow detail? All he wanted of course, but how does it compare to Caponigro, or Frederick Evans? It depends on how you look at it, and what's important to you.

Lenny

[Kevin Crisp]

To amplify on what Lenny said, do a proper test with your meter and your developing method. Then you know. My 125 probably isn't going to be your 125 unless you steal my meter. Unless two people are using the same model meter and both were just calibrated by the same person "what iso are you using?" isn't particularly useful. That doesn't stop people from asking the question all the time, of course.

[Sal Santamaura]

...Nicely done. However, you failed to include the most important point. What kind of shadow detail do you like in your prints...The kind of shadow detail obtainable from negatives made after establishing IE using the type of detailed testing protocol I described varies with shape of the characteristic curve's toe.

I did include that most important point. It was implicit in the last line (accompanied by :) :) ). Despite a tested EI of 160, "I shoot it at 125."

[EdWorkman]

I recall an article in Modern Photography [or another- hey it's my recall, right or wrong] that explained the then ASA standard for determining film speed.
BUT
Most folks throw ASA/ISO around as if it were the same as EI- exposure index, which is what really works for them, with all the YMMV that comes with what a person works with, not that everybody doesn't get the intended meaning. [ ISO is ISO is ISO, done ONLY per International Standard- if you don't follow the Standard- and why should you- it isn't ISO]
And from what I think I remember, here's how ASA speed was determined
A VERY SPECIFIC developer
Used to obtain a negative of "fairly high" [my weasel words] but VERY SPECIFIC contrast, and measure the speed at a VERY SPECIFIC point on the density curve.
That COULD mean speed at the expense of too much contrast and many folks use a personal EI that is below the officially obtained ASA/DIN/ISO printed on the box.
One obvious reason to use the above is it's the "only way" to compare films in an instrumented way. And "only way" probably means the "only way" a bunch of Standards folks could agree- there had been maybe 3 major speed ratings and probly a couple dozen others in use over the first half of the previous century.

Use the EI you want, adjust it after you see the results, change your developer [ but don't get crazy at first] , or adjust your EI until the film believes your techniques.
It can be rocket science or it can be shooting by starting with the box speed, bracketing and oops, adjusting, or being happy with the box speed, or higher.

Experience is the only way, in the end, that will lead to pictorial success- seeeee the film beeeeee the film.