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Ilford processing times (Pan F)



 
 
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  #1  
Old July 21st 10, 10:42 PM posted to rec.photo.darkroom
David Nebenzahl
external usenet poster
 
Posts: 1,353
Default Ilford processing times (Pan F)

After my recent success with TMX, I delved into my freezerful of film
and pulled out a roll of Pan F I want to shoot. But I'm a bit mystified
by the enclosed processing instructions.

Was thinking of using D-76, and they have times for both this and ID-11
(same times, since the same developer, except that they list ID-11 at
1+1 but not D-76, though I assume I can also dilute it). But they show
the same times for both ISO 25 and 50 exposure. Can this be correct?
Other developers show different times for the two speeds.

They also show times for Perceptol, but not Microdol-X. Richard K., you
said these developers were equivalent: would you use the same times for
both of these? The Humumgous Massive Really Really Big Dev Chart
(http://www.digitaltruth.com/devchart.php) shows different times for
these (9 min. for Perceptol vs 12 min. for Microdol; should I just use
their recommendations?


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)
  #2  
Old July 22nd 10, 12:45 PM
IanG IanG is offline
Junior Member
 
First recorded activity by PhotoBanter: Dec 2009
Posts: 7
Default

The MDC is not as reliable as the Manufacturers own data because we don't know who or how the poster reached their figures.

Ilford's Data is here and a far better starting point.

http://www.ilfordphoto.com/Webfiles/...6115811391.pdf

Ian

Quote:
Originally Posted by David Nebenzahl View Post
After my recent success with TMX, I dTHe MDC is unfortunately not elved into my freezerful of film
and pulled out a roll of Pan F I want to shoot. But I'm a bit mystified
by the enclosed processing instructions.

Was thinking of using D-76, and they have times for both this and ID-11
(same times, since the same developer, except that they list ID-11 at
1+1 but not D-76, though I assume I can also dilute it). But they show
the same times for both ISO 25 and 50 exposure. Can this be correct?
Other developers show different times for the two speeds.

They also show times for Perceptol, but not Microdol-X. Richard K., you
said these developers were equivalent: would you use the same times for
both of these? The Humumgous Massive Really Really Big Dev Chart
(http://www.digitaltruth.com/devchart.php) shows different times for
these (9 min. for Perceptol vs 12 min. for Microdol; should I just use
their recommendations?


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)
  #3  
Old July 22nd 10, 07:32 PM posted to rec.photo.darkroom
David Nebenzahl
external usenet poster
 
Posts: 1,353
Default Ilford processing times (Pan F)

On 7/22/2010 4:45 AM IanG spake thus:

[corrected for top-posting, and WTF happened to my quoted text?]

David Nebenzahl;884098 Wrote:

After my recent success with TMX, I dTHe MDC is unfortunately not elved
into my freezerful of film
and pulled out a roll of Pan F I want to shoot. But I'm a bit mystified
by the enclosed processing instructions.

Was thinking of using D-76, and they have times for both this and ID-11
(same times, since the same developer, except that they list ID-11 at
1+1 but not D-76, though I assume I can also dilute it). But they show
the same times for both ISO 25 and 50 exposure. Can this be correct?
Other developers show different times for the two speeds.

They also show times for Perceptol, but not Microdol-X. Richard K., you
said these developers were equivalent: would you use the same times for
both of these? The Humumgous Massive Really Really Big Dev Chart
(http://www.digitaltruth.com/devchart.php) shows different times for
these (9 min. for Perceptol vs 12 min. for Microdol; should I just use
their recommendations?


The MDC is not as reliable as the Manufacturers own data because we
don't know who or how the poster reached their figures.

Ilford's Data is here and a far better starting point.

http://www.ilfordphoto.com/Webfiles/...6115811391.pdf


Thanks; I should have checked that first. As it turns out, the Ilford
sheet agrees with the Massive Dev Chart.

What it doesn't agree with is some of Ilford's own printed information:
both the inside of the film carton and the large Ilford film processing
chart I have (came with a box of paper, I think) have the same times for
ISO 25 and 50 for three developers (ID-11, Microphen and D-76) which
can't be correct. The PDF you gave us a link to appears to have the
correct data. Must be typos, I guess.

So now my only dilemma is whether I should de-rate the film at 25 or go
for the extra stop (50) and develop longer (I plan on using Microdol-X).
Any opinions on this?


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)
  #4  
Old July 22nd 10, 07:44 PM posted to rec.photo.darkroom
David Nebenzahl
external usenet poster
 
Posts: 1,353
Default Ilford processing times (Pan F)

On 7/22/2010 11:39 AM Digitaltruth spake thus:

The Massive Dev Chart is more reliable than the published data sheets
released by manufacturers. Why? Because it incorporates the official
information that you will find in the manufacturer's data sheets, AND
it includes additional user submissions and amendments. I've spent 15
years collating and editing this data, which is a lot more time than
the manufacturers spend on it.

While some manufacturers, most notably Ilford and Fuji, provide
excellent data based on their own in-house analysis, many other
manufacturers are far less thorough. In fact, there are several
official data sheets currently being published which include data from
the Massive Dev Chart as the primary source, even though I doubt the
manufacturers have ever tested it themselves.


[snip]

Well, I for one very much appreciate, and have made much use of, your
Humungous Ginormous Dev Chart. My hat is off to you.

And as I pointed out in another post here, some of Ilford's own
documentation has obviously erroneous data: both the inside of the film
carton and the large Ilford Film Processing Chart that I have show
identical (and therefore obviously incorrect) times for ISO 25 & 50
times for three different developers for Pan F.

Your chart agrees perfectly with the Ilford PDF supplied elsewhere in
this thread, which appears to be correct.


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)
  #5  
Old July 24th 10, 07:55 AM posted to rec.photo.darkroom
Richard Knoppow
external usenet poster
 
Posts: 751
Default Ilford processing times (Pan F)


"Digitaltruth" wrote in message
...
The Massive Dev Chart is more reliable than the published
data sheets
released by manufacturers. Why? Because it incorporates
the official
information that you will find in the manufacturer's data
sheets, AND
it includes additional user submissions and amendments.
I've spent 15
years collating and editing this data, which is a lot more
time than
the manufacturers spend on it.

While some manufacturers, most notably Ilford and Fuji,
provide
excellent data based on their own in-house analysis, many
other
manufacturers are far less thorough. In fact, there are
several
official data sheets currently being published which
include data from
the Massive Dev Chart as the primary source, even though I
doubt the
manufacturers have ever tested it themselves.

One of the recurrent questions about the Massive Dev Chart
is why
Ilford's published times for developing film in Kodak D-76
are only
included if they are the same as the published times for
ID-11. The
reason for this is because the chemical composition of
these two
developers is almost identical. In fact, the difference is
sufficiently small so as to be negligible for all intents
and
purposes. Ilford's data for its own products is highly
reliable, so
when there is a significant variance between times for
third-party
chemicals such as D-76, then it is safe to assume that the
testing
procedure was different and should not be relied on if it
does not
match that of ID-11.

Perceptol and Microdol-X are not the same developer,
although they
have similar characteristics. Different times are
required, so you
should use the data for each developer in The Massive Dev
Chart to
provide the required starting point.

If you study official data sheets you will notice that
manufacturers
often update the times even though no changes have been
made to their
products. Conversely, Kodak changed many times when they
modified the
film base on several products a few years back, but other
published
studies showed that the original times were more accurate.
You can
also see that, famously in the case of Agfa, they release
different
data in different countries. Trusting something just
because it is
printed by the manufacturer is does not offer any
guarantee of
accuracy.

The most important part of any issues regarding accuracy
of
development times is to understand that ALL times are
starting point
recommendations, regardless of the source, and it is up to
the
individual user to use these starting points to determine
the optimum
development in relation to subject contrast, print
contrast and
enlarging equipment.

--Jon Mided

http://www.digitaltruth.com

If you check the MSDS you will find that Microdol-X and
Perceptol are essentially identical. I say essentially
because both manuacturers probably have additions in the
form of sequestering agents that do not show up in MSDS.
Also, Kodak has patented method of preparing some of the
ingredients they use. The published formulas for D-76 and
ID-11 are the same but the packaged developers may be
different. The MSDS for D-76 shows it to be the buffered
formula similar to the published D-76d. Packaged ID-11 may
also be buffered but no buffering agent shows up in the
MSDS.
Manufacturers' data is generated by use of proper
sensitometry, at least its supposed to be and I think Kodak
and Ilford data are reliable. One difference between the two
is that some time ago Ilford stopped using the ISO method to
rate film. The ISO standard is correct for a contrast index
about right for diffusion enlarging and contact printing.
When lower contrast is desired for condenser enlargers the
development must be adjusted with a consequent change in
effective film speed. Ilford appears to use a contrast index
mid-way between condenser and diffusion values. This results
in a slight lowering of effective speed when the film is
developed to diffusion contrast and accounts for the
differnce in developing times for Ilford film given by
Ilford and some others.


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



  #6  
Old July 24th 10, 08:05 AM posted to rec.photo.darkroom
Richard Knoppow
external usenet poster
 
Posts: 751
Default Ilford processing times (Pan F)


"David Nebenzahl" wrote in message
.com...
After my recent success with TMX, I delved into my
freezerful of film and pulled out a roll of Pan F I want
to shoot. But I'm a bit mystified by the enclosed
processing instructions.

Was thinking of using D-76, and they have times for both
this and ID-11 (same times, since the same developer,
except that they list ID-11 at 1+1 but not D-76, though I
assume I can also dilute it). But they show the same times
for both ISO 25 and 50 exposure. Can this be correct?
Other developers show different times for the two speeds.

They also show times for Perceptol, but not Microdol-X.
Richard K., you said these developers were equivalent:
would you use the same times for both of these? The
Humumgous Massive Really Really Big Dev Chart
(http://www.digitaltruth.com/devchart.php) shows different
times for these (9 min. for Perceptol vs 12 min. for
Microdol; should I just use their recommendations?


You will notice that Kodak also rates T-Max 100 and 400
at double speed with normal development. The differece
between the two exposure indices is a difference in overall
density and in shadow detail, the contrast remains the same.
When the ASA system of speeds was introduced in 1943 it
included a safety factor of two so that all film speeds were
half the value actually determined by the test method. For
some reason this was thought to be a good idea even though
the research at Kodak from which the standard was adopted
was intended to find the _minimum_ exposure possible for
good tonal rendition. This was because film is somewhat less
grainy and somewhat sharper for thin images. Nontheless, the
lower speeds were recommended. I think the reason is that
Kodak, in particular, wanted to insure amateur users would
get a printable image and overexposure does less damage than
underexposure. In 1958 when the ASA adopted a modification
of the then new DIN standard, which was much easier to
measure than the minimum gradient method previously used,
they also dropped the fudge factor and all film speeds were
doubled! That put the manufacturers of "magic" speed
increasing developers out of business. They all knew and
counted on the fact that all films were actually double the
speed given by the ASA. Kodak actually talks about this in
the introduction to the film booklet included in the _Kodak
Reference Handbook_ but its obscured by recommending
increased speed only to essentially professionals.
In any case many photographers find that increasing
exposure from that given by the ISO speed often results in
better shadow rendition and, with modern thin-emulsion film
has little effect on grain or sharpness.


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



 




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