krishnananda <k@[EMAIL PROTECTED]
> wrote:
> For the past ten years or so I have been using HP5+ as my primary B/W
> emulsion, having found it to be contrastier than Tri-X, which I had used
> for the previous 20 years.
>
> Now I'm finding that Tri-X is more contrasty -- to my eye -- than HP5+.
> Has anyone else noticed this? Some variables are taken care of: same
> lab, same cameras/lenses, usually same developing batch, side-by-side
> comparison of the negs and contacts. Tri-X has a purple mask and HP5+
> doesn't, but I'm not sure what difference that makes.
Differences in developing-time or -temperature?
You can trim any film to any contrast index you like by developing
it longer or shorter (and adjusting exposure). If HP5+ is too contrasty,
shorten your development by 15%... (for a first approximation).
You typically can't adjust curve shape by changing developers and/or
times, a straight or s-type density curve is built into the emulsion. It
is possible (by a very low margin) to get a slight shoulder in a density
curve by using twobath-development, but I haven't found that too useful.
Martin
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