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Toe speed of TMAX 400 (was fridge and heat problems)



 
 
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  #11  
Old July 15th 04, 03:40 PM
jjs
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Default Toe speed of TMAX 400 (was fridge and heat problems)

Be careful when comparing manufacturer's curves. A visual glance at the
chart can give misimpressions. You have to plot each film using the same X,Y
metrics. Further, you do not know what kind of light was used. And finally,
some charts go off the scale of usable density.


  #12  
Old July 15th 04, 05:47 PM
Peter De Smidt
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Default Toe speed of TMAX 400 (was fridge and heat problems)

jjs wrote:
Be careful when comparing manufacturer's curves. A visual glance at the
chart can give misimpressions. You have to plot each film using the same X,Y
metrics. Further, you do not know what kind of light was used. And finally,
some charts go off the scale of usable density.



That's good advice, and I'll add that curves that I produce myself give
me better information than ones produced by manufacturers, since I know
the conditions of the test, and it takes into consideration my
photographic system (exposure, development,...)

I'll add that a number of enlarging papers from major manufacturers have
reduced highlight contrast. Using a film/development combo with reduced
highlight contrast (i.e. a shoulder) can result in overly flat high
print values. I had that problem with PMK. It's a fine developer, but
it didn't give me what I wanted with the film and paper that I wanted to
use.

As usual, Mikey doesn't know what he's talking about. At best, he's
overgeneralizing tremendously, and no amount of name-calling is going to
change that. Sure, if you want do reportage style photos in full sun of
a polar bar at the zoo while guessing at exposure, Mikey's forte, then
TMY might not be the best choice. The best choice would be for Mikey to
stay home and take his meds.

-Peter
  #13  
Old July 15th 04, 06:07 PM
jjs
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Default Toe speed of TMAX 400 (was fridge and heat problems)

"Peter De Smidt" pdesmidt*no*spam*@tds.*net* wrote in message
...

That's good advice, and I'll add that curves that I produce myself give
me better information than ones produced by manufacturers, since I know
the conditions of the test, and it takes into consideration my
photographic system (exposure, development,...)


I would dearly like to learn how to measure and plot B&W film color response
myself. Does anyone have pointers to _good_ articles? Please, no Zone System
tutorials. I'm cool with the ZS but for now I'd just like to learn the
metrics of doing my own plots of color response for B&W film.

It would be so very cool to know how Agfa B&W film responds in the light we
actually _use_ (Daylight).

As usual, Mikey doesn't know what he's talking about. At best, he's
overgeneralizing tremendously [...]


I suspect he doesn't shoot large format. It really is a different world than
35mm.


  #14  
Old July 15th 04, 06:07 PM
jjs
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Default Toe speed of TMAX 400 (was fridge and heat problems)

"Peter De Smidt" pdesmidt*no*spam*@tds.*net* wrote in message
...

That's good advice, and I'll add that curves that I produce myself give
me better information than ones produced by manufacturers, since I know
the conditions of the test, and it takes into consideration my
photographic system (exposure, development,...)


I would dearly like to learn how to measure and plot B&W film color response
myself. Does anyone have pointers to _good_ articles? Please, no Zone System
tutorials. I'm cool with the ZS but for now I'd just like to learn the
metrics of doing my own plots of color response for B&W film.

It would be so very cool to know how Agfa B&W film responds in the light we
actually _use_ (Daylight).

As usual, Mikey doesn't know what he's talking about. At best, he's
overgeneralizing tremendously [...]


I suspect he doesn't shoot large format. It really is a different world than
35mm.


  #15  
Old July 15th 04, 07:11 PM
Peter De Smidt
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Default Toe speed of TMAX 400 (was fridge and heat problems)

jjs wrote:

I would dearly like to learn how to measure and plot B&W film color response
myself. Does anyone have pointers to _good_ articles? Please, no Zone System
tutorials. I'm cool with the ZS but for now I'd just like to learn the
metrics of doing my own plots of color response for B&W film.


Couldn't you use a MacBeth Color Checker, along with transmission and
reflection densitometers, to do this? I just bought the book "Way
Beyond Monochrome." I'll check if it has any useful information on this.

-Peter
  #16  
Old July 15th 04, 07:31 PM
Severi Salminen
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Default Toe speed of TMAX 400 (was fridge and heat problems)

When film is developed to a
lower CI, for instance for use in condenser enalarger, it
must be developed less and the speed will be lower than that
give by the ISO test. For most film an adjustment to a one
paper grade lower contrast will require an increase in
exposure of about 3/4 to 1 stop. The difference in printing
contrast between a diffusion enlarger and a common partly
diffuse condenser enlarger is about one paper grade.


This puzzles me. I allways thought that condenser enlargers only
increase the contrast of the final print - nothing more, nothing less.
If we first decrease contrast (developing less, agitating less etc.)and
then increase the contrast back to normal using a condenser enlarger,
why would one have to expose at different EI? Shound't the decrease in
development negate the effect of using condenser and thus not call for
any change in EI?

Example, using diffusing enlarger, EI = (say) ISO/2 and we develop
"normally" and get:

Zone I at 0.10 above fb+f (so the used EI is "correct")
Zone X at 1.30 above fb+f

Let's assume that it prints very well. Let's also assume that condenser
enlarger increases contrast by a factor of 1.25.

So using condenser, EI = ISO/2 and we develop now a little less:

Zone I at 0.08 above fb+f (now the used EI seems to be too high)
Zone X at 1.04 above fb+f

Now using condenser the above "becomes" 0.10 and 1.30 above fb+f -
actually only the resulting densities at the print change but... So why
would I increase EI at the latter example? If I increase the EI to get
Zone I at 0.1, the result is that Zone I prints as 0.125 (1.25 x
(0.08+0.02)) and Zone X as 1.325 (1.25 x (1.04+0.02)). That would be
incorrect, right?

Regards,
Severi Salminen
  #17  
Old July 15th 04, 07:47 PM
jjs
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Default Toe speed of TMAX 400 (was fridge and heat problems)

"Peter De Smidt" pdesmidt*no*spam*@tds.*net* wrote in message
...
jjs wrote:

I would dearly like to learn how to measure and plot B&W film color

response
myself. Does anyone have pointers to _good_ articles? Please, no Zone

System
tutorials. I'm cool with the ZS but for now I'd just like to learn the
metrics of doing my own plots of color response for B&W film.



Couldn't you use a MacBeth Color Checker, along with transmission and
reflection densitometers, to do this? I just bought the book "Way
Beyond Monochrome." I'll check if it has any useful information on this.


Peter, I just ordered the book. Sounds interesting.


  #18  
Old July 16th 04, 04:47 AM
Peter De Smidt
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Default Toe speed of TMAX 400 (was fridge and heat problems)

Michael Scarpitti wrote:



Probably because you don't understand that it messes up VC paper by
lowering the contrast in the areas where the stain is heaviest
(highlights). If you use a staining developer, use GRADED paper only.

Duh. I just said that PMK lowers highlight contrast with vc paper. The
stain acts much like a green filter. About using PMK with VC paper, you
must know much more about it than Gordon Hutchings, who developed PMK,
wrote a carefully detailed book about it, and makes better prints than
Mikey can even dream of. Mikey, maybe you should try pouring syrup on
that polar bear. That'd be "high art", at least for you.

Oh, yeah, nice job completely ignoring the point which was that a film
with a pronounced S curve is not always the best choice for outdoor
work, contra your categorically stated position, especially with the
major Kodak and Ilford printing papers. These papers have been modified
to have lower highlight contrast since shortly after tabular and core
grained films were released. It's how the negative and paper curves
work together to make the print that's important, but you're clearly too
mentally disturbed to realize that. Let me guess, before photography,
glue sniffing was your main hobby, right?

-Peter

  #19  
Old July 16th 04, 04:47 AM
Peter De Smidt
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Posts: n/a
Default Toe speed of TMAX 400 (was fridge and heat problems)

Michael Scarpitti wrote:



Probably because you don't understand that it messes up VC paper by
lowering the contrast in the areas where the stain is heaviest
(highlights). If you use a staining developer, use GRADED paper only.

Duh. I just said that PMK lowers highlight contrast with vc paper. The
stain acts much like a green filter. About using PMK with VC paper, you
must know much more about it than Gordon Hutchings, who developed PMK,
wrote a carefully detailed book about it, and makes better prints than
Mikey can even dream of. Mikey, maybe you should try pouring syrup on
that polar bear. That'd be "high art", at least for you.

Oh, yeah, nice job completely ignoring the point which was that a film
with a pronounced S curve is not always the best choice for outdoor
work, contra your categorically stated position, especially with the
major Kodak and Ilford printing papers. These papers have been modified
to have lower highlight contrast since shortly after tabular and core
grained films were released. It's how the negative and paper curves
work together to make the print that's important, but you're clearly too
mentally disturbed to realize that. Let me guess, before photography,
glue sniffing was your main hobby, right?

-Peter

  #20  
Old July 16th 04, 07:25 AM
jjs
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Posts: n/a
Default Toe speed of TMAX 400 (was fridge and heat problems)


"Peter De Smidt" pdesmidt*no*spam*@tds.*net* wrote in message
...
[... speaking to MS...]
Oh, yeah, nice job completely ignoring the point which was that a film
with a pronounced S curve is not always the best choice for outdoor
work, contra your categorically stated position, especially with the
major Kodak and Ilford printing papers. These papers have been modified
to have lower highlight contrast since shortly after tabular and core
grained films were released. [...]


That's interesting. I wonder if that's the reason I'm so unhappy with their
papers. I don't use it for those films. (I grew up spoiled rotten with an
unlimited supply of Agfa graded papers and still haven't recovered from the
loss.)


 




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