HP5 Plus & Pyrocat-HD shadow separation

[Tom Kershaw]

While my standard medium format films are the ILFORD DELTA series I've been using 10"x8" HP5 Plus for my limited large format work so far. Having processed four sheets in Pyrocat-HD using rotary processing I subjectively noticed a distinct difference in the way the HP5 film dealt with shadow separation, - there seems to be less, at least in comparison with a film I'm very familiar with, Delta 100. The increased contrast effect of Pyrocat-HD was also in evidence printing on Kentmere Kentona; achieving approximately the same contrast as grade 4 on Kentmere Fineprint.

I realise HP5 Plus and Delta 100 have different characteristic curves, but my thoughts were more towards how Pyrocat-HD affects the reproduction of shadow areas. I was exposing with reciprocity in mind by tapping out 240 seconds, evidently providing another variable.

Development data (which produced good results in general):

23ºC, 11 minutes, 50 r.p.m, 1+1+100 dilution

Tom.

 

[Thomas Bertilsson]

If you feel you don't have enough shadow separation from HP5, perhaps you need to expose it differently?

And if you get too much contrast while printing, your negative has too much contrast, meaning you need to shorten your development time or change your agitation scheme to softer/less agitation. Do you process in tray or rotary or other method?

There is no reason you couldn't get shadow detail with any film out there, if you expose enough.

- Thomas

 

[Tom Kershaw]

Thomas,

The film probably needed more exposure. However, films do respond differently in terms of tone reproduction. I don't have too much contrast as such, I was commenting more on the distribution of tones.

Tom.

 

[sanking]

What do you mean by shadow separation? Do you mean that there is less texture or detail in the shadows or that the shadow values are compressed?

Sandy Kingf

Having processed four sheets in Pyrocat-HD using rotary processing I subjectively noticed a distinct difference in the way the HP5 film dealt with shadow separation, - there seems to be less, at least in comparison with a film I'm very familiar with, Delta 100.

Tom.

 

[Tom Kershaw]

The shadow values seem compressed. There is detail.

 

[Ian Grant]

HP5 isn't my favourite film but it's all Ilford offer in 400 ISO LF, I far prefer Delat 100 & 400..

I have to frequently shoot hand-held 5x4 so bought 2 100 sheet boxes of short-dated HP5+ from the US, I used some again on Sunday to shoot quite a contrasty scene with deep shadows and the film coped exceptionally well, I do use it at 200 EI though, in Pyrocat HD 1+1+100 15 mins @ 20ºC, inversion agitation.

However it sounds more like a reciprocity problem with your negs, 4 minutes is quite a long exposure, last time I was anywhere near that I was deep inside a canal tunnel with Tmax100

Reciprocity can affect the shadow contrasts, and it sounds like this may have happened, choice of developer won't have made a significant difference here.

Ian

 

[Andrew Moxom]

Tom, printing these negs is the only way to know for sure. I have played with HP5+ and Pyrocat for pinhole shots and the negs are quite punchy from what I have seen. I've not tried a comparison with Delta 100, but they are totally different film emulsions at any rate, why would they respond the same?