FP4 vs HP5- when to use one over the other?

[Drew Wiley]

I have used both films in both 4x5 and 8x10 formats. I prefer HP5 in the larger camera
because of the extra speed and exquisite edge effect; but it starts getting a little mushy-looking with 4x5 (or potentially grainy if you use certain developers). Both films
have a moderate toe but less than Delta films, and have better acutance than Delta.
Since you have 5x7 in mind, both films are tempting. Lately I've been carrying both
films around with the the 8X10, since each has its advantages. I develop in Pyro.

[Steve Sherman]

First let me say that I believe strongly in one film one developer, learn them and stick with them.

That said, the two films you mention have distinctively different profiles (characteristics) I have both films but considerably more FP than HP5.

Very basically, the FP 4 has much more "built in contrast" shorter toe and sharper rise to the straight line. While the HP5 has a longer toe and longer shoulder, in other words the HP5 is capable of handling more contrasty scenes than the FP4.

If your concerns lie solely in film speed than we are decidedly photographers and therefore my preferences will not matter.

2 cents, Cheers

[Gem Singer]

Steve,

I look at the difference between HP-5+ and FP-4+ in a more simplistic way.

FP-4+ is a higher contrast film than HP-5+. Therefore, it adds contrast to a flatly lit scene (fog, or overcast conditions). However, has a lower sensitivity to light.

HP-5+ is a lower contrast film. Therefore, it reduces the contrast to a harshly lit scene (outdoors in bright sunlight). However, it has an increased sensitivity to light.

The problem is that on a dull overcast day (less light) I usually need a faster film, like HP-5+, to hold my exposures within reasonable bounds.

[Drew Wiley]

What Steve mentioned reminded me of another functional distinction. When you have the shorter toe of FP4 you get better separation of shadow details, PROVIDED
your exposure is sufficient to boost the shadow values onto the straighter section of
the characteristic curve. With HP5 you have better odds getting "something" in the
shadows with an exposure that is a bit off, but it won't be well distinguished. The
longer toe tends to lump shadows together. I don't really like either film for extreme lighting ratios, where a true straight-line film can do a better job. But for
general work, I like HP5 when I don't have to trust shadow values below Zone III.
Overexposing this film will blow out the highlights, unless you develop with certain
secret elixirs or print using a silver contrast mask. FP4 will tolerate a bit of overexp,
so I generally rate it as ASA 50 for "normal" pyro dev. Of course, you can always do
N-1 development or something equivalent, but then you lose that wonderful internal
contrast and excellent edge effect which these films are prized for.

[timbo10ca]

Thanks everybody for your responses. I never really seriously considered dropping FP4 entirely but was curious if HP5 could cover the majority of its application. It sounds like what I have read elsewhere has been confirmed, and that these 2 films are different enough to use in different applications (low contrast =FP4 and high contrast =HP5). Like I said previously and Gem reiterated, The low light scenes where you need the speed of HP5 don't seem to be its best application, so I wonder how to approach those situations- stick with FP4 and just use the longer shutter speeds like I have already been doing?

Steve- I'm glad you chimed in, as you've really helped me in the past. I'm wondering how you feel about semistand with HP5 in Pyrocat HD- I tried some tests using your article (1.5:1:150) and time adjustments from what I found doing FP4, but I haven't printed them yet to see the results. I'm wondering if semistand is the way to go with HP5 or just stick to Sandy King's recommendation of 2:2:100 tray processing for this film. I don't think I'll worry too much about dev past N+ with it, because if I had to go that far I'd be better off using FP4. I'm thinking tray shuffle for N and semistand for N+1 and various N-. Any thoughts/input?

Thanks.

[Kerik Kouklis]

I've used both of these films for many years in 14x17 and other sizes. In a nutshell, I use FP4 for soft light and HP5 for contrasty light (assuming other factors like shutter speed aren't important).

[Drew Wiley]

Kerik - you are no doubt contact printing? With enlargement the equation might
change, as it's easy to blow out the highlights with HP5, unless one knows some
advanced dev or printing techniques like masking. Contrary to some of the stereotypes above, I find HP5 at its best in softer lit situations, because when you apply expanded (plus) dev you also get the best internal contrast and edge effect.
But this is quite a versatile film if you spend the time to learn its options.

[Ken Lee]

I'm not a sensitometry expert, but looking at Sandy King's study of these films in Pyrocat HD, I gather that HP5+ is quite linear - in the visible spectrum - in its response to changes in development.

Correct me if I'm wrong, but HP5+ appears to be as linear as TMY - and superior in that regard, to FP4+.

Because TMY is unavailable in 5x7, I've been trying HP5+ lately. The combination of HP5+ and Pyrocat HD seems to do quite nicely, and hasn't blocked up in the high values.

[timbo10ca]

I'm not a sensitometry expert, but looking at Sandy King's study of these films in Pyrocat HD, I gather that HP5+ is quite linear - in the visible spectrum - in its response to changes in development.

Correct me if I'm wrong, but HP5+ seems as linear as TMY - and superior in that regard, to FP4+.

Because TMY is unavailable in 5x7, I've been trying HP5+ lately. The combination of HP5+ and Pyrocat HD seems to do quite nicely, and hasn't blocked up in the high values.

Ken- how are you using the P-HD (tray/etc, dilution,temp...etc)?

[Ken Lee]

I "tray-develop" my negatives in these Sterilite food containers. Pyrocat HD 1:1:100 for ~12 minutes at 70 degrees. I learned about affordable plastic containers from Carl Weese, who uses large ones instead of photo trays, when making Platinum/Palladium prints.

I perform development by inspection (using an Infra Red viewing device), and prefer the greater dilution because I prefer a longer development time. Because the Sterilite containers are deep rather than wide, I routinely develop up to 20 or more negatives at a time. Longer development time allows some latitude or "fudge factor". Greater dilution also saves developer - but Pyrocat HD is already so affordable, it hardly matters.

Speaking of saving money and other resources, you might find this interesting: how to make your own Dishrack Film Washer for a few bucks.

I shoot HP5+ at a speed of 200, just as I do for TMY. I shoot FP4+ at 50. Giving one extra f/stop is an old habit, left over from the 1970's, which I can't shake, but which seems to work OK.