H&D curves of different films

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Jytzel - 23 Sep 2003 14:47 GMT

I'd appreciate if somebody can comment on the characteristics curves
of the following films:

APX 100
APX 400
FP4 125
Pan F plus 50
HP5 400
Acros
Delta 400

thanks

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Martin Jangowski - 23 Sep 2003 15:14 GMT

In rec.photo.darkroom Jytzel <jytzel@netscape.net> wrote:

> I'd appreciate if somebody can comment on the characteristics curves
> of the following films:

> APX 100
> APX 400
[quoted text clipped - 3 lines]
> Acros
> Delta 400

What characteristic curves? Every developer and every development
time will give different curves...

Martin

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Richard Knoppow - 23 Sep 2003 16:47 GMT

> In rec.photo.darkroom Jytzel <jytzel@netscape.net> wrote:
> > I'd appreciate if somebody can comment on the characteristics curves
[quoted text clipped - 12 lines]
>
> Martin

The developer will have some effect on the curve but its
mainly determined by the distribution of sensitivity of the
silver halide particals in the emulsion. This is turn is
controlled by the exact method by which the emulsion is
made.
Two extremes are the recently discontinued Plus-X Pan
sheet film compared to T-Max 100. Plus-X Pan sheet film (the
roll film is different)has a curve which is constantly swept
upward. In other words the contrast increases continuously
with density. T-Max 100, OTHO, has a fairly straight
characteristic. The two will be different regardless of the
developer used although some will give a slightly straighter
curve with both than others.
The difference results in a difference in the tonal
rendition. When the same shadow and highlight points are
chosen the upswept type film will reproduce mid-gray tones
darker than the straight line film. Kodak intended this to
be used for studio photography where it was desired to
exagerate highlights. Tri-X sheet film is similar to Plus-X
but not quite so steeply rising.
You will find a number of characteristic curves for
popular films in several developers at:
http://www.fotoimport.no/pg02/PG02-1-1.htm#tab

Most of these look reasonably correct.
The site is in Norwegian but one can navigate it pretty
well.

Signature

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com

--

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com

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Jytzel - 24 Sep 2003 14:02 GMT

> > In rec.photo.darkroom Jytzel <jytzel@netscape.net> wrote:
> > > I'd appreciate if somebody can comment on the
[quoted text clipped - 42 lines]
> The site is in Norwegian but one can navigate it pretty
> well.

Thanks Richard,
I know about tri-x, PX and TMX, but what about Verichrome pan? To my
eye it seems that it has an upsept curve to a certain degree (I tried
it with D-76, HC110, DK-50, and Rodinal) It was my favourite film. So
bad it was discontinued. I'm looking for a replacement (PX is not an
option). HP4+ seems to have an S-shaped curve. APX 100 seems to have a
unique curve - long toe round shoulder (?)- I'm not sure. Can anybody
help me interpret them?

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Richard Knoppow - 26 Sep 2003 23:45 GMT

> "Richard Knoppow" <dickburk@ix.netcom.com> wrote in message

news:<aWZbb.503$NX3.443@newsread3.news.pas.earthlink.net>...

> > > In rec.photo.darkroom Jytzel <jytzel@netscape.net> wrote:
> > > > I'd appreciate if somebody can comment on the
[quoted text clipped - 51 lines]
> unique curve - long toe round shoulder (?)- I'm not sure. Can anybody
> help me interpret them?

V-Pan was also a favorite of mine. I finished off the two
bricks I had and haven't seen any more. Probably the closest
is Plus-X Pan roll film. This has a similar (but not
identical) sort of curve and is also a very fine grain
relativly high resolution film. I think it gets short shrift
because people think its the same as the now discontinued
Plus-X sheet film. Its a very different emulsion. APX-100 is
very good film but grainier than Plus-X. FP-4 is also
similar but has somewhat different tonal rendition. Kodak's
published curves are pretty reliable. Agfa and Ilford tend
to publish idealized curves which makes them harder to
compare.
About the only way to really tell how a film responds
tonaly is to try some.
As pointed out elswhere in this thread developers have
some, but not a lot, of effect on curve shape, with the
exception of compensating developers, which create a
shoulder. i.e., they reduce the contrast of the highlights.
This is sometimes desirable but can also result in rather
distorted tonal rendition.

Signature

Richard Knoppow
Los Angeles, CA, USA

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Jytzel - 30 Sep 2003 12:15 GMT

"Richard Knoppow" <dickburk@ix.netcom.com> wrote in message news:<fk3db.4510>

> V-Pan was also a favorite of mine. I finished off the two
> bricks I had and haven't seen any more. Probably the closest
[quoted text clipped - 10 lines]
> About the only way to really tell how a film responds
> tonaly is to try some.

Richard,

What do you mean by "different"?

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Jytzel - 23 Sep 2003 18:49 GMT

> In rec.photo.darkroom Jytzel <jytzel@netscape.net> wrote:
> > I'd appreciate if somebody can comment on the characteristics curves
[quoted text clipped - 12 lines]
>
> Martin

regarding developer-to a certain extent yes, but it's mainly a
property of the emulsion itself rather than the devloper . Development
times affects the steepness of the curve but not the shape.

thanks

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Martin Jangowski - 24 Sep 2003 09:12 GMT

In rec.photo.darkroom Jytzel <jytzel@netscape.net> wrote:

>> In rec.photo.darkroom Jytzel <jytzel@netscape.net> wrote:
>> > I'd appreciate if somebody can comment on the characteristics curves
[quoted text clipped - 12 lines]
>>
>> Martin

> regarding developer-to a certain extent yes, but it's mainly a
> property of the emulsion itself rather than the devloper . Development
> times affects the steepness of the curve but not the shape.

Time will (more or less) affect the steepness of the curve, but different
developers have al lot more influence on the curve form. I tested the
APX100, Delta 100 and 400 with several developers, including Xtol, ID11,
Microphen, D23, DS-1, Spur SLD and Stoeckler, using a homebuild
sensitometer and a Heiland TRD-2 densitometer.

Indeed, the "mainstream"-developers had nearly identical curves, it is
possible to get very similar results with Xtol, ID11, Microphen
etc. However, Spur SLD and Stoeckler were able to bend the curves very
strongly, to the extend to deliver a straight portion between toe and
about 1.4d and then making a more or less strong shoulder, going
asymptotic to a defined value or at least going up much more slowly.
So, the choice of developer _will_ have an effect on curves.

Martin

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Jorge Omar - 23 Sep 2003 19:35 GMT

See my earlier post: Compensating film dev - here!
There I've posted a small Norwegian-English glossary.

Jorge

> I'd appreciate if somebody can comment on the characteristics curves
> of the following films:
[quoted text clipped - 8 lines]
>
> thanks

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Michael Scarpitti - 23 Sep 2003 20:10 GMT

> I'd appreciate if somebody can comment on the characteristics curves
> of the following films:
[quoted text clipped - 8 lines]
>
> thanks

I'm not sure I or anyone here understands what you mean by 'comment'.
You can look at any H&D curve and see what we see. There's really not
much to comment about. Besides, each developer/film combination
produces a slightly different curve. If you want to ask something
specific.....

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Jytzel - 24 Sep 2003 13:49 GMT

> > I'd appreciate if somebody can comment on the characteristics curves
> > of the following films:
[quoted text clipped - 14 lines]
> produces a slightly different curve. If you want to ask something
> specific.....

Please refrain from answering any of my posts. I won't take it seriously anyway.

'comment' means 'comments'. Check out what Richard wrote.

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Martin Jangowski - 24 Sep 2003 16:43 GMT

In rec.photo.darkroom Jytzel <jytzel@netscape.net> wrote:

[...]

> Please refrain from answering any of my posts. I won't take it seriously anyway.

Easy. Just mark him for your killfile, and you won't see him any more... just like me.

Martin

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Michael Scarpitti - 24 Sep 2003 19:52 GMT

> > > I'd appreciate if somebody can comment on the characteristics curves
> > > of the following films:
[quoted text clipped - 18 lines]
>
> 'comment' means 'comments'. Check out what Richard wrote.

You'll forgive my impertinence, but the 'films' don't have curves by
themselves. A film/developer/dilution/agitation
pattern/temperature/time combination will have a curve. So you see I
would have to ask you for further specificity before answering your
question. As well, what particular aspect of the curve would be of
importance to you? Is it the suitability for ceratin kinds of work?
Speed? These are all necessary before 'comments' are even possible.

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Jytzel - 24 Sep 2003 23:17 GMT

> > > > I'd appreciate if somebody can comment on the characteristics curves
> > > > of the following films:
[quoted text clipped - 26 lines]
> importance to you? Is it the suitability for ceratin kinds of work?
> Speed? These are all necessary before 'comments' are even possible.

I don´t want you to answer my question. Don´t you understand idiot?!

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Michael Scarpitti - 25 Sep 2003 03:06 GMT

> > > > > I'd appreciate if somebody can comment on the characteristics curves
> > > > > of the following films:
[quoted text clipped - 28 lines]
>
> I don´t want you to answer my question. Don´t you understand idiot?!

Your question was poorly framed. I wished to point that out to you,

SIR!

If you need help even FRAMING THE QUESTION, which one of us is the idiot?

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