I have been shuffling between 4X5 HP5 and Tri-X hoping to see the difference and decide on what I want. I think I see the difference, but I don't know. Maybe I am just willing it. So I tried an experiment that could be called anecdotal. Same camera, same lens, same subject, almost the same exposure (320/400 +/- erratic shutter). Somehow HP5 is lighter? not as heavy? I don't know. The HP5 skintones looked (I know it's not a word) more marzipan-ish. The Tri-X looked, well, normal. I'm going with HP5, but I'd like to know if it just because I am stubborn and delusional, or if you can really see a difference. Something in my gut tells me that there can't be any difference.

Dean

-- Dean Lastoria (dvlastor@sfu.ca), June 08, 2000

Answers

I'm guess they differ in HD curve shape (pick a toe, any toe) and spectral sensitivity. These are things you can't make up for in exposure and development. It's OK, just use what looks best to you, we won't tell anyone...

-- Tim Brown (brownt@ase.com), June 08, 2000.

Try the same experiment using Diafine. Shoot the negs at the same time and process them in the same batch and then make the decision... Scott

-- Scott Walton (scotlynn@shore.net), June 08, 2000.

In 4x5, the shape of the H&D curve is different (4x5 Tri-X is TXP, not TX), so the films do produce different results. HP5+ is actually closer to regular medium format and 35mm Tri-X (TX) as opposed to Tri- X Pro (TXP).

Part of the confusion is that there are two very different films called "Tri-X." This dates back to before WWII when the original Tri- X was a sheet film, and smaller formats used Double-X as their highest speed film. When Kodak discontinued 35mm Double-X in the early 1950's, they called its replacement "Tri-X" but it wan't the same film as the sheet film version.

TXP (the sheet film version) is formulated for studio portrait use with hot lights. This is one reason why there is so much nostalgia among zone system types for the old double-X sheet film, which had a long straight line section of the H&D curve.

IMHO (as a TX user since the late 1950's), HP5+ is much better suited for landscape use than TXP. Of course, that's just another way of saying it behaves more like TX :-)

-- John Lehman (ffjal@uaf.edu), June 09, 2000.

Life was simpler when I thought speed was the only choice. Scott, I was waiting to decide on one film BEFORE I tried a new developer, but maybe I'll just go all out, try the Diafine, and heck, maybe DDX too then I'll make all my decisions at once from six possible outcomes. And then I'll stop experimenting for at least 3 years. And it makes life doubly dificult if Tri-x is so many differnt films -- I thought that I would standardize on sheet and roll too. Thanks for your help. Dean

-- Dean Lastoria (dvlastor@sfu.ca), June 09, 2000.

Dean, if you want a simpler life, being a serious photographer is NOT the answer! I get much better results with Ilford films than any other. Tri-X is the only Kodak film that I would use for personal work. Using my color densitometer, I have determined that HP-5+ has an EI of 200 (same as Tri-X) when developed in PMK. Xtol may get anywhere from 1/3 to 2/3 stop more 'speed' from most films, but it has a little more fog. You may want to try PMK (Pyro-Metol-Kodalk) developer. You can dramatically reduce the time it takes to make fine prints from negatives developed in this developer.

-- Michael D Fraser (mdfraser@earthlink.net), June 16, 2000.

Michael, PMK is on my goal sheet for 2 or 3 years from now. OK, I'm paranoid, but I will wait until I have a semi-dedicated darkroom, properly ventilated as I heard it is deadly poison. I don't want life REAL simple; I just don't want to make it harder than it has to be. Thanks, Dean

-- Dean Lastoria (dvlastor@sfu.ca), June 19, 2000.

Dean, I'm continually amazed at how many people are frightened of pyro! There are MUCH more toxic chemicals used in household cleaning. If you follow the safety precautions outlined in the instructions (mix outdoors or under a 'ventilator'i.e. a range hood) and don't drink the 'A' solution, and don't soak your hands in the developer, you will be quite safe. Whatever you do, though, DO NOT mix amonia and bleach! The fumes will kill you in less than 30 seconds! There's no warning labels on either of those chemicals, is there?

-- Michael D Fraser (mdfraser@earthlink.net), June 21, 2000.

Oh, I know I'm irrational about the whole PMK thing, and I think the images I've seen using the stuff are amazing -- those 'wow, I'd like to do that' as opposed to an 'oh yea, that's nice' kind of photo. But I'm not quite there yet. I tried DDX this week, and I'll try the suggested Diafine next week (payday -- man is that stuff pricey). Though it is encouraging to know that PMK isn't as bad as it is rumored to be. Thanks for your ideas as I try to take the next developmental (get it?) step.

Dean

-- Dean Lastoria (dvlastor@sfu.ca), June 21, 2000.

Dean, you can buy PMK pre-mixed from Photographer's Formulary (http://www.photoformulary.com). I just got some. I'll use rubber gloves while I use it but aside from that I see no reason for precautions. The most dangerous thing about PMK is pyrogallol dust; using a liquid concentrate minimizes the risk of exposure.

-- Jim MacKenzie (photojim@yahoo.com), June 23, 2000.