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pushing time shorter than normal time?



 
 
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  #1  
Old July 15th 06, 07:11 AM posted to rec.photo.darkroom
Steven Woody
external usenet poster
 
Posts: 164
Default pushing time shorter than normal time?

i noticed in Kodak's TMX data sheet, it says that normal development
time for D76 is 7 1/4 min, for pushing to EI200, it is 6 1/2 min. i
can not understand this.

  #2  
Old July 15th 06, 11:06 AM posted to rec.photo.darkroom
Richard Knoppow
external usenet poster
 
Posts: 751
Default pushing time shorter than normal time?


"Steven Woody" wrote in message
ps.com...
i noticed in Kodak's TMX data sheet, it says that normal
development
time for D76 is 7 1/4 min, for pushing to EI200, it is 6
1/2 min. i
can not understand this.

Which data sheet is this? I am looking at F-4016 January
2002 which is I think the current one. It gives 6-1/2
minutes for both speeds, small tank, 68F. This is in line
with Kodak's claim that T-Max films can be underexposed one
stop wtih no adjustment in developing time.
I see 7-1/4 minutes at 68F using D-76 for large tank
processing of T-Max 100 at normal speed but the push
processing charts for large tanks do not show D-76 at all.
Check the data sheet for its number and date, I have some
of the older ones too, and also tell me which charts you are
getting the data from.
Note that Kodak has made misprints in the past.


--
---
Richard Knoppow
Los Angeles, CA, USA



  #3  
Old July 16th 06, 12:29 AM posted to rec.photo.darkroom
Richard Knoppow
external usenet poster
 
Posts: 751
Default pushing time shorter than normal time?


"Steven Woody" wrote in message
oups.com...

Richard Knoppow wrote:
"Steven Woody" wrote in message
ps.com...
i noticed in Kodak's TMX data sheet, it says that normal
development
time for D76 is 7 1/4 min, for pushing to EI200, it is
6
1/2 min. i
can not understand this.

Which data sheet is this? I am looking at F-4016
January
2002 which is I think the current one. It gives 6-1/2
minutes for both speeds, small tank, 68F. This is in line
with Kodak's claim that T-Max films can be underexposed
one
stop wtih no adjustment in developing time.
I see 7-1/4 minutes at 68F using D-76 for large tank
processing of T-Max 100 at normal speed but the push
processing charts for large tanks do not show D-76 at
all.
Check the data sheet for its number and date, I have
some
of the older ones too, and also tell me which charts you
are
getting the data from.
Note that Kodak has made misprints in the past.


that doc i mentioned is in my office and i can not touch
it now. but i
just checked the F-4016 in my home computer, i found the
devlopment
time in the doc are all 9 mins for normal speed and EI200
pushing, it
still differ with what you said. this version is F-4016,
March 2002.

-
woody

Are you sure you have F-4016 and not F-32? The 9 minute
time is given in F-32, which is the data brochure for the
old T-Max, the web version is dated March 2002 because of a
notice of the discontinuance of the film. The latest edition
of F-4016 is dated February 2002. I am not sure what
revisions were made to the edition I had but the times for
the new T-Max are the same.
A change from 9 minutes to 6-1/2 minutes is substantial.
Rumor is that the overcoating of the film was changed. The
original T-Max 100 and T-Max 400 were designed to have very
similar development times so that they could be processed
together. This is not true of the current films. The
overcoating has an effect on the induction time, that is,
the time between immersion the film in the developer and the
first appearance of the image.
In any case, the times for one stop pushing are the same
as for normal processing.


--
---
Richard Knoppow
Los Angeles, CA, USA



  #4  
Old July 17th 06, 02:54 AM posted to rec.photo.darkroom
Richard Knoppow
external usenet poster
 
Posts: 751
Default pushing time shorter than normal time?


"Steven Woody" wrote in message
ups.com...

Richard Knoppow wrote:
"Steven Woody" wrote in message
oups.com...

Richard Knoppow wrote:
"Steven Woody" wrote in message
ps.com...
i noticed in Kodak's TMX data sheet, it says that
normal
development
time for D76 is 7 1/4 min, for pushing to EI200, it
is
6
1/2 min. i
can not understand this.

Which data sheet is this? I am looking at F-4016
January
2002 which is I think the current one. It gives 6-1/2
minutes for both speeds, small tank, 68F. This is in
line
with Kodak's claim that T-Max films can be
underexposed
one
stop wtih no adjustment in developing time.
I see 7-1/4 minutes at 68F using D-76 for large
tank
processing of T-Max 100 at normal speed but the push
processing charts for large tanks do not show D-76 at
all.
Check the data sheet for its number and date, I
have
some
of the older ones too, and also tell me which charts
you
are
getting the data from.
Note that Kodak has made misprints in the past.


that doc i mentioned is in my office and i can not
touch
it now. but i
just checked the F-4016 in my home computer, i found
the
devlopment
time in the doc are all 9 mins for normal speed and
EI200
pushing, it
still differ with what you said. this version is
F-4016,
March 2002.

-
woody

Are you sure you have F-4016 and not F-32? The 9
minute
time is given in F-32, which is the data brochure for the
old T-Max, the web version is dated March 2002 because of
a
notice of the discontinuance of the film. The latest
edition
of F-4016 is dated February 2002. I am not sure what
revisions were made to the edition I had but the times
for
the new T-Max are the same.
A change from 9 minutes to 6-1/2 minutes is
substantial.
Rumor is that the overcoating of the film was changed.
The
original T-Max 100 and T-Max 400 were designed to have
very
similar development times so that they could be processed
together. This is not true of the current films. The
overcoating has an effect on the induction time, that is,
the time between immersion the film in the developer and
the
first appearance of the image.
In any case, the times for one stop pushing are the
same
as for normal processing.


--
---
Richard Knoppow
Los Angeles, CA, USA


many thanks to you. i think i was using F-32 for
development of my
T-MAX. it is amazing the those nagatives still show
images :-)
actually, i've been using 12 mins in D-76 1:1, that should
be 9 1/2
instead.

another question is, Kodak not list pushing time for D-76
1:1, how can
i get know of it? i think, from EI100 to EI200, the time
is no change
for D-76, so do D-76 1:1 ( 9 1/2 mins ); from E1100 to
EI400, the time
changed to 8 1/4 mins which is 27% longer for D-76, so do
D-76 1:1 ( 9
1/2 * 1.27 = 12 mins ). am i right? thanks.

-
woody



I use D-76 1:1 for T-Max routinely because I prefer the
longer development times. I think for EI 200 I would follow
the instructions for other developers, that is, no change
from normal development. As a rule of thumb a one stop push
requires about 1.5 times the "normal" time but I've seen
Kodak instructions that suggest less. perhaps 30% increase.
Beware that increasing development time does not really
increase speed. It only increases contrast but the toe
region of the characteristic curve, where the low exposure
part of the image is, is also increased in contrast, which
may make the images easier to print. The downside is that
the contrast of the more normally exposed parts of the image
will become very contrasty. Where you must push film the
ideal lighting is pretty flat, however, one can not often
choose in available light situations.
Using a Phenidone developer will give you about 3/4 stop
greater speed for the same contrast. They are better push
developers than D-76. Among them are Kodak T-Max and T-Max
RS, Xtol, Ilford Microphen, formula ID-68, and DDX, and a
few others. With the exception of Xtol these all produce
slightly coarser grain than D-76.
Xtol is pretty close to being an optimum developer for
many purposes but has proven to be somewhat unreliable.
Ryuji Suzuki, a biological chemist, has done considerable
research into developers and emulsions. Some of it is
detailed on his web site at
http://www.silvergrain.org. He
has formulated a developer similar to Xtol but with some
attention to curing Xtol's short time failure problem. It is
now being put up commercially by Photographer's Formulary,
details are on his web site.


--
---
Richard Knoppow
Los Angeles, CA, USA



  #5  
Old July 17th 06, 02:56 AM posted to rec.photo.darkroom
Richard Knoppow
external usenet poster
 
Posts: 751
Default pushing time shorter than normal time?


"Steven Woody" wrote in message
ups.com...

Richard Knoppow wrote:
"Steven Woody" wrote in message
oups.com...

Richard Knoppow wrote:
"Steven Woody" wrote in message
ps.com...
i noticed in Kodak's TMX data sheet, it says that
normal
development
time for D76 is 7 1/4 min, for pushing to EI200, it
is
6
1/2 min. i
can not understand this.



A correction: I am not sure if Ryuji Suzuki's film
developer is available commercially yet. He has some paper
developers which are. The formula for his film developer is
on his web site. http://www.silvergrain.org You will have
to do some poking around to find it.


--
---
Richard Knoppow
Los Angeles, CA, USA



  #6  
Old July 17th 06, 09:23 AM posted to rec.photo.darkroom
Steven Woody
external usenet poster
 
Posts: 164
Default pushing time shorter than normal time?


Richard Knoppow wrote:
"Steven Woody" wrote in message
ups.com...

Richard Knoppow wrote:
"Steven Woody" wrote in message
oups.com...

Richard Knoppow wrote:
"Steven Woody" wrote in message
ps.com...
i noticed in Kodak's TMX data sheet, it says that
normal
development
time for D76 is 7 1/4 min, for pushing to EI200, it
is
6
1/2 min. i
can not understand this.

Which data sheet is this? I am looking at F-4016
January
2002 which is I think the current one. It gives 6-1/2
minutes for both speeds, small tank, 68F. This is in
line
with Kodak's claim that T-Max films can be
underexposed
one
stop wtih no adjustment in developing time.
I see 7-1/4 minutes at 68F using D-76 for large
tank
processing of T-Max 100 at normal speed but the push
processing charts for large tanks do not show D-76 at
all.
Check the data sheet for its number and date, I
have
some
of the older ones too, and also tell me which charts
you
are
getting the data from.
Note that Kodak has made misprints in the past.


that doc i mentioned is in my office and i can not
touch
it now. but i
just checked the F-4016 in my home computer, i found
the
devlopment
time in the doc are all 9 mins for normal speed and
EI200
pushing, it
still differ with what you said. this version is
F-4016,
March 2002.

-
woody

Are you sure you have F-4016 and not F-32? The 9
minute
time is given in F-32, which is the data brochure for the
old T-Max, the web version is dated March 2002 because of
a
notice of the discontinuance of the film. The latest
edition
of F-4016 is dated February 2002. I am not sure what
revisions were made to the edition I had but the times
for
the new T-Max are the same.
A change from 9 minutes to 6-1/2 minutes is
substantial.
Rumor is that the overcoating of the film was changed.
The
original T-Max 100 and T-Max 400 were designed to have
very
similar development times so that they could be processed
together. This is not true of the current films. The
overcoating has an effect on the induction time, that is,
the time between immersion the film in the developer and
the
first appearance of the image.
In any case, the times for one stop pushing are the
same
as for normal processing.


--
---
Richard Knoppow
Los Angeles, CA, USA


many thanks to you. i think i was using F-32 for
development of my
T-MAX. it is amazing the those nagatives still show
images :-)
actually, i've been using 12 mins in D-76 1:1, that should
be 9 1/2
instead.

another question is, Kodak not list pushing time for D-76
1:1, how can
i get know of it? i think, from EI100 to EI200, the time
is no change
for D-76, so do D-76 1:1 ( 9 1/2 mins ); from E1100 to
EI400, the time
changed to 8 1/4 mins which is 27% longer for D-76, so do
D-76 1:1 ( 9
1/2 * 1.27 = 12 mins ). am i right? thanks.

-
woody



I use D-76 1:1 for T-Max routinely because I prefer the
longer development times. I think for EI 200 I would follow
the instructions for other developers, that is, no change
from normal development. As a rule of thumb a one stop push
requires about 1.5 times the "normal" time but I've seen
Kodak instructions that suggest less. perhaps 30% increase.
Beware that increasing development time does not really
increase speed. It only increases contrast but the toe
region of the characteristic curve, where the low exposure
part of the image is, is also increased in contrast, which
may make the images easier to print. The downside is that
the contrast of the more normally exposed parts of the image
will become very contrasty. Where you must push film the
ideal lighting is pretty flat, however, one can not often
choose in available light situations.
Using a Phenidone developer will give you about 3/4 stop
greater speed for the same contrast. They are better push
developers than D-76. Among them are Kodak T-Max and T-Max
RS, Xtol, Ilford Microphen, formula ID-68, and DDX, and a
few others. With the exception of Xtol these all produce
slightly coarser grain than D-76.
Xtol is pretty close to being an optimum developer for
many purposes but has proven to be somewhat unreliable.
Ryuji Suzuki, a biological chemist, has done considerable
research into developers and emulsions. Some of it is
detailed on his web site at
http://www.silvergrain.org. He
has formulated a developer similar to Xtol but with some
attention to curing Xtol's short time failure problem. It is
now being put up commercially by Photographer's Formulary,
details are on his web site.


--
---
Richard Knoppow
Los Angeles, CA, USA


thanks for your information!

 




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