Prewarming film emulsion
 

Recently, while inquiring about E-6 kits at my local camera store, one of
the co-owners (brothers) described one of the kits, Tetenal, I think.
Reading from a product description, he said that particular kit required one
to "prewarm" the emulsion, presumably using warm water at 104 degress
Fahrenheit.

This got me to thinking: Could one use a similar approach with B&W? While
I'm not sure how it would affect development times, softening the emulsion
may enable the developer to do its work. (However, I should note that it's
been some time since I developed ANY film.)

Dieter Zakas
--
Good, better, best; never let it rest, until your good is better and your
better is best. (Billy Cox)

Prewarming film emulsion
 

On Fri, 25 Nov 2005 21:06:15 -0600, Dieter Zakas
wrote:

Recently, while inquiring about E-6 kits at my local camera store, one of
the co-owners (brothers) described one of the kits, Tetenal, I think.
Reading from a product description, he said that particular kit required
one
to "prewarm" the emulsion, presumably using warm water at 104 degress
Fahrenheit.
This got me to thinking: Could one use a similar approach with B&W? While
I'm not sure how it would affect development times, softening the
emulsion may enable the developer to do its work. (However, I should
note that it's been some time since I developed ANY film.)

Most if not all manufacturers recommend that you do not "prewet" the films
prior to development as the water in the emulsion may impede develoment
progress and uneven development is theoretically possible. Note that I've
never heard of such a case. The other reason that don't recommend the
practice is that the rinse tends to rinse out the wetting agent that is
included in the film.

--

Regards,

John S. Douglas, Photographer & Webmaster
http://www.puresilver.org - http://www.legacy-photo.com

Prewarming film emulsion
 

John spake thus:

On Fri, 25 Nov 2005 21:06:15 -0600, Dieter Zakas
wrote:

Recently, while inquiring about E-6 kits at my local camera store, one of
the co-owners (brothers) described one of the kits, Tetenal, I think.
Reading from a product description, he said that particular kit
required one
to "prewarm" the emulsion, presumably using warm water at 104 degress
Fahrenheit.
This got me to thinking: Could one use a similar approach with B&W?
While I'm not sure how it would affect development times, softening
the emulsion may enable the developer to do its work. (However, I
should note that it's been some time since I developed ANY film.)

Most if not all manufacturers recommend that you do not "prewet" the
films prior to development as the water in the emulsion may impede
develoment progress and uneven development is theoretically possible.
Note that I've never heard of such a case. The other reason that don't
recommend the practice is that the rinse tends to rinse out the wetting
agent that is included in the film.

So what difference would that make? Once the film is wet, why would you
need wetting agent?


--
.... asked to comment on Michigan governor George Romney's remark that
the army had "brainwashed" him in Vietnam—-a remark which knocked Romney
out of the running for the Republican nomination—-McCarthy quipped,
"I think in that case a light rinse would have been sufficient."

(Eugene McCarthy, onetime candidate for POTUS)

Prewarming film emulsion
 

Phototherm's black and white programs prewet the film and Jobo has in the
past (and may still) recommend a five minute prewash when processing black
and white. Since the temperature that black and white is normally processed
at is only a little above room temp the pre-wet is not so much for tempering
as it is for evenness of development. I currently use a Unicolor Film Drum
and motor base and use a five minute prewash. I have tried shorter presoaks
and with some combinations of film and developer got less than ideal
results. If you are going to use a presoak with black and white stick with
5 minutes. (At least until you can test and come up with a shorter standard
minimum time that works with all the combinations and permutations of film
type, developer type, temperature and agitation that you will use in your
own work!)

--
darkroommike

----------
"Dieter Zakas" wrote in message
...
Recently, while inquiring about E-6 kits at my local camera store, one of
the co-owners (brothers) described one of the kits, Tetenal, I think.
Reading from a product description, he said that particular kit required
one
to "prewarm" the emulsion, presumably using warm water at 104 degress
Fahrenheit.

This got me to thinking: Could one use a similar approach with B&W? While
I'm not sure how it would affect development times, softening the emulsion
may enable the developer to do its work. (However, I should note that it's
been some time since I developed ANY film.)

Dieter Zakas
--
Good, better, best; never let it rest, until your good is better and your
better is best. (Billy Cox)

Prewarming film emulsion
 

Dieter Zakas a écrit :
Recently, while inquiring about E-6 kits at my local camera store, one of
the co-owners (brothers) described one of the kits, Tetenal, I think.
Reading from a product description, he said that particular kit required one
to "prewarm" the emulsion, presumably using warm water at 104 degress
Fahrenheit.

This got me to thinking: Could one use a similar approach with B&W? While
I'm not sure how it would affect development times, softening the emulsion
may enable the developer to do its work. (However, I should note that it's
been some time since I developed ANY film.)

Dieter Zakas

E-6 pre-warming is usually done *without* water, often during 5' to warm
up the tank/reel/film before 1st developer in which temperature is critical.

For B/W, both schools exist: pre-wetting or not.
Pre-wetting can be useful for short development times and reduces the
risk of developer streaks with larger formats.
You have to adapt your development time.
Personally I don't feel the need to pre-wet ...

Best regards,
Claudio Bonavolta
http://www.bonavolta.ch

Prewarming film emulsion
 

In article op.s0t09xxpuvfup0@jd, John wrote:

The other reason that don't recommend the
practice is that the rinse tends to rinse out the wetting agent that is
included in the film.

If that's the case how would the other three solutions fail to wash out
the wetting agent/ or do you mean there is wetting agent incorporated
to make the initial developer evenly coat the film? Btw I have never
added wetting agent to any film prior to the final rinse.
--
"To announce that there must be no criticism of the President,
or that we are to stand by the President, right or wrong,
is not only unpatriotic and servile, but is morally treasonable
to the American public."--Theodore Roosevelt, May 7, 1918

www.gregblankphoto(dot)com

Prewarming film emulsion
 

In article ,
Dieter Zakas wrote:

Recently, while inquiring about E-6 kits at my local camera store, one of
the co-owners (brothers) described one of the kits, Tetenal, I think.
Reading from a product description, he said that particular kit required one
to "prewarm" the emulsion, presumably using warm water at 104 degress
Fahrenheit.

Well unless it states prewarming is done with water as a prewet, it is
an assumption. Not always good to assume!

This got me to thinking: Could one use a similar approach with B&W? While
I'm not sure how it would affect development times, softening the emulsion
may enable the developer to do its work. (However, I should note that it's
been some time since I developed ANY film.)

Here's my take: you'll get as many answers as practitioners, but
prewetting 5 minutes seems excessive, however 5 minutes prewarming is
probably correct, you do want to have the film-reel and tank at the
process temperature. By prewarming your insuring the times are accurate
for development, because times are established (hopefully) without lag
time factored as an unknown. Any time the film etc must come up to the
process temp -lag time exists.

I typically do prewash my large format film, ONE/TWO minutes
only....I feel it washes out the back anti reflection coating and does
warm the film up more quickly....I have never had problems but I
bidirectionally rotate or rock my drum drums during process.

I am quite sure there are many correct answers to your question as
the process can take a lot of variation and still yield VG results.
--
"To announce that there must be no criticism of the President,
or that we are to stand by the President, right or wrong,
is not only unpatriotic and servile, but is morally treasonable
to the American public."--Theodore Roosevelt, May 7, 1918

www.gregblankphoto(dot)com

Prewarming film emulsion
 

On Fri, 25 Nov 2005 23:23:47 -0600, John
wrote:

Most if not all manufacturers recommend that you do not "prewet" the films
prior to development as the water in the emulsion may impede develoment
progress and uneven development is theoretically possible. Note that I've
never heard of such a case. The other reason that don't recommend the
practice is that the rinse tends to rinse out the wetting agent that is
included in the film.


November 26, 2005, from Lloyd Erlick,

And here I've been pre-soaking my film before
the developer for lo these many years ... oh,
well, wrong again.

regards,
--le
________________________________
Lloyd Erlick Portraits, Toronto.
voice: 416-686-0326
email:
net: www.heylloyd.com
________________________________
--

Prewarming film emulsion
 

Lloyd Erlick spake thus:

On Fri, 25 Nov 2005 23:23:47 -0600, John
wrote:

Most if not all manufacturers recommend that you do not "prewet"
the films prior to development as the water in the emulsion may
impede develoment progress and uneven development is theoretically
possible. Note that I've never heard of such a case. The other
reason that don't recommend the practice is that the rinse tends to
rinse out the wetting agent that is included in the film.

And here I've been pre-soaking my film before the developer for lo
these many years ... oh, well, wrong again.

I wouldn't say "wrong"; it's hard to see how a presoak could have any
ill effects, like uneven development. Seems to me it would have quite
the opposite effect, as the emulsion is thoroughly wet and the chemistry
can more easily diffuse through it. Wonder what Richard K. has to say
about this.


--
.... asked to comment on Michigan governor George Romney's remark that
the army had "brainwashed" him in Vietnam—-a remark which knocked Romney
out of the running for the Republican nomination—-McCarthy quipped,
"I think in that case a light rinse would have been sufficient."

(Eugene McCarthy, onetime candidate for POTUS)

Prewarming film emulsion
 

On Sat, 26 Nov 2005 06:50:36 -0600, Gregory Blank
wrote:

In article op.s0t09xxpuvfup0@jd, John wrote:

The other reason that don't recommend the
practice is that the rinse tends to rinse out the wetting agent that is
included in the film.

If that's the case how would the other three solutions fail to wash out
the wetting agent/ or do you mean there is wetting agent incorporated
to make the initial developer evenly coat the film?

I believe that it is included in the emulsion during the coating.

--

Regards,

John S. Douglas, Photographer & Webmaster
http://www.puresilver.org - http://www.legacy-photo.com