Long/short toe film for low key effect?

[Miha]

What sort of film would be most appropriate for achieving low key effect portraiture? TXP (not TX) was a long toe film intended for studio use where highlight separation plays the most important role. Somehow I always thought that the situation is reversed; long toe should give good separation of lower tones. What's the truth here?

The photo below was taken on PanF, enlarged on Fomatone 542. I like the result very much, but the film (exposed ar E.I. 32) is slow and I often wish for something faster. What fast film have similar characteristic curve to PanF?



This is the PanF characteristic curve - is this a short or long toe film?



I know that Low / High key are more related to the composition of tones, than to a specific curves but at this point I'm interested in matching the two.

Thanks.

[PavelDerka]

I'm not an expert but I would say that the graph there shows a very long toe curve with no shoulder and I would think that it is the opposite that such a characteristic is the opposite of what one would want for low key.

[Miha]

Thanks Pavel, I see the same, however PanF developed in ID11 did a remarkable job here, so I wonder

a) does the shoulder play a role in achieving low key
b) if so, in what way

[PavelDerka]

Now, keep in mind the emphasis on "I'm no expert"!

my thought was that less toe would separate out the print shadows well. I hope someone else chimes in because I'd like to understand material application better myself.

[Trevor Crone]

http://www.ilfordphoto.com/Webfiles/...1054152313.pdf

If you scroll to page 5 you will see the characteristic film curve for HP5 where you can see the toe is quite short and requires relatively less exposure to register equivalent negative density. By exposure log1 the curve has started to rise whereas Pan F requires approx. exposure log2. You can also see that the straight line section is not as steep as Pan F indicating that it is not as contrasty.

My experience with Pan F was if I wanted shadow detail I could never use it at the box speed and rated it at 25 iso, it does need a bit of a 'kick' to get it started

Miha I would have thought Pan F would be ideal for low-key work. You can control highlights by development time just keep shadows (exposure) down at the toe and they will show very little detail.

You could try the newly formulated TriX which may have a steeper film curve then HP5 but I've not researched it.

[Miha]

Thanks Trevor, TriX is my most used film in 35mm as it is the cheapest here.

It seem I need more reading on this:

http://micro.magnet.fsu.edu/primer/p...mexposure.html

and
http://www.sprawls.org/ppmi2/FILMCON/

[Martin Aislabie]

Originally Posted by Trevor Crone

http://www.ilfordphoto.com/Webfiles/...1054152313.pdf
You could try the newly formulated TriX which may have a steeper film curve then HP5 but I've not researched it.

A steeper film curve can be achieved simply by extending development time.

The 320asa version of Tri-X has an upswinging shoulder to increase seperation in the highlights - which would give great high key shots

Films like FP4 have a very rounded shoulder so high key details are compressed towards single tones.

Martin

[SteveBenskin]

One thing to consider when comparing films is how they will be affected by flare. Flare is lower under studio conditions than in exterior scenes. When you compare the resulting densities from a subject shot with a long toed curve under studio conditions and a normal toed film under exterior conditions, they will be similar.

[cliveh]

Originally Posted by SteveBenskin

One thing to consider when comparing films is how they will be affected by flare. Flare is lower under studio conditions than in exterior scenes. When you compare the resulting densities from a subject shot with a long toed curve under studio conditions and a normal toed film under exterior conditions, they will be similar.

That depends on the lighting arrangement. I agree with Trevor, Pan F is probably ideal.