Hp5 at ASA 141???

[Drew Wiley]

What on earth kind of developer are you using? I dev it in PMK, which is not exactly a high-ASA developer, and have been using full box speed (400) all along.

[StoneNYC]

I shoot it at 800 haha :-p

[Drew Wiley]

What I find so odd about this is that I routinely cut the box speed of every other Ilford film in half; it's only HP5 that I shoot at full speed. Same meters, same dev
strategy, same cameras.

[Harold_4074]

Drew, interesting observation. I also use PMK, metering FP4 at 80 but HP5 at 320. Back when I used Plus-X and Tri-X, they were also metered at half box speed, which seems to be typical for PMK. For some reason, HP5 doesn't mess up the upper mid tones when slightly underexposed the way the other films do.

Neil: you are comparing a calculated 140 versus 200, presumably based on instrumental data rather than the printing qualities of the resulting negatives, so the above comment may not be as relevant to you. But do you have a reference sample of film against which to confirm your processing? Kodak process control strips were carefully manufactured and handled for precisely the reason that it is not trivial to manage consistent development without some sort of reliable reference.

[Drew Wiley]

HP5 has a relatively long toe; so I don't particularly care for it in high-contrast situations to begin with. But it can work wonders in certain kinds of lighting, and I like
the speed for 8x10 use. Rarely shoot it in any format smaller than that. I should qualify this by stating that I like HP5 negs a bit "thick" in order to accentuate the
midtone microcontrast and edge effect this film renders so nicely. But a slight overdevelopment like this can render the highlights difficult to print. So the only way
I can have my cake and eat it too is to use a supplementary silver mask, even with today's excellent VC papers. Yet the net result of this extra effort can be something quite special. Otherwise I've standardized on TMY400, which I find more versatile; and it will dig way down into the shadows and resolve values there in
a way HP5 simply can't. Having this option, HP5 will still remain one of my favorite films for 8x10. It does have a special look.

[Jim Noel]

You are not exposing at ASA 141. You are exposing at ASA 400, with an EI of 141.
Something is off in your system. This could be your meter, your shutter speeds, or your processing.
This said, if it works for you , use it.

[Brian C. Miller]

But do you have a reference sample of film against which to confirm your processing? Kodak process control strips were carefully manufactured and handled for precisely the reason that it is not trivial to manage consistent development without some sort of reliable reference.

Unique Photo still carries color control strips (link), but did anyone ever make B&W control strips?

[dsphotog]

Thanks for using ASA, it's what my camera's & meter's have on them.

[Peter Gomena]

Kodak manufactured B&W film strips. We used them when I was a first-year student at Brooks Institute of Photography, which was more than 20 years ago.

[Bill Burk]

I thought that I would do a sanity check; mine!

But before you render an opinion, let me explain . . .

I just completed a speed test for Ilford's HP5, and determined that the speed of my box of film is ASA 141, which is a half-stop better than ASA 100, and of course a half-stop worse than ASA 200.

Is this consistent with the results that others have obtained? Normally, I come up with ASA 200, so I guess it isn't so far off of typical. But, I thought that I would check.

I've accurately taken into account bellows expansion and actual shutter speed. My FB+F was 0.08, and my target was 0.18. I checked my densitometer with a Stouffer's standard that I keep on hand, and it's accuracy appears to be satisfactory.

Do your tests include a measure of contrast? Just curious if you judge film speed at the same development time that reaches 0.62 contrast. Or do you develop to Zone System classic "N" time which gives you a certain Zone IX density calibrated to your printing paper.

And also curious if you are doing classic Zone System speed test, where you meter and then stop down to Zone I.

The answer to those two questions can easily account for a stop from Box Speed. Then all that would have to happen for you to "lose" another half stop, is some deviation like choice of developer, minor processing mistakes like time and temperature...

In other words you are sane, it's not uncommon to find personal speeds that are different than manufacturer rated speed.