Road ruts with Jobo

LABFIX 2 wrote:

2. If you are processing B&W, do not use a stop bath between dev and fix.

Why not?

I have seen the use of a stop bath cause a blotchy appearance. Most easily seen
with high key backgrounds.

O.K., but given (1) enough solution is used (and you can use as much stop as you
want so I'd use twice the minimum volume) and (2) the stop bath does the same
thing the fix initially does, namely stop development, I don't see how uneven
development could result. It should take the same amount of time for development
to cease via diffusion with either stop or fix steps, so exactly when fixing
begins should be irrelevant.

OTOH I could see uneven development perhaps resulting if either a plain water stop
or too weak a stop was used; or if too little solution was being used for either
development or stop. I generally use and recommend a somewhat stronger than normal
stop bath for Jobo processing. Personally I suspect "road ruts" is caused by
something people are doing with the processor or processing, not the processor
itself. So, I agree that with sheet film the expert film drums are best (I use a
3010.) In addition I'd presoak the film, make sure adjusted b&w development times
are long enough (several minutes), and make sure (duh...) the processor is
perfectly level and the drum rotates properly and consistently (reverse rotation,
not one directional.) With the 3000 series film drums it's also important to watch
the drum, since the original Jobo motors can stall with these heavy 3000 film
drums laden with solution.

Jean-David Beyer wrote:

LABFIX 2 wrote:

The volume listed on the tank only indicates the amount of chemistry needed to
cover the film. You may need to use more than indicated. (especially with b&w
diluted developers)

I am not convinced of that. I cannot imagine anyone used a developer
until the last few ions are depleted. So if the developer is "too
dilute" you just need to develop longer.

But there are minimum solution requirements for the drums, and I myself tend to use
a bit more than the minimum. Dilution of course is compensated for by time, and I
think Jobo has always recommend nothing shorter than 5 minutes for b&w.

My suggestions were for people who are having problems. If you get uniform
repeatable results, then keep doing what your doing. Cheers!

OK: I hope your suggestions are helpful. I have more trouble with people
who say you cannot get uniform repeatable results with a rotary
processor, or Jobo rotary processors in particular. Maybe they cannot.

Let's see: if it is not the earth's magnetic field, is it the phase of
the moon? the sign of the Zodiac? ... ;-)

Eureka, that's it! Lunar tidal action on the developer!

Brian Kosoff wrote:

However when the subject matter switches to large even white
backgrounds, the un evenness is very evident.

In regards to perception. I remember talking to the technicians from Sinar
about the fact that my expolux shutter was really only accurate in 1/3 stop
increments and not in the 1/4 stop increments that were stated in the Sinar
brochure. I was told that the motors needed to move a diapraghm
consistently to an opening as small as f32 or 45, could not be counted on
for that degree of accuracy in 1/4 stop increments. Fair enough. However
they went on to say that most people can not discern any differences greater
than 1/3 of a stop anyway. This last part blew me away. Every photographer I
knew in NYC, either bracketed in 1/4s or push/pulled in 1/4s and it was a
very obvious difference to all those I knew, In fact my own e-6 processing
was processed in 1/8 stop increments and that difference was clearly
discernible to me. Were the Sinar techs lying or in error? Or is it true
that most people can not discern differences smaller than 1/3 stop?

1/4 stop is visually evident in transparency films, but pragmatically I see no
difference between 1/3 and 1/4.

Maybe some of those reporting even processing, that have not used
densitometers, are simply not seeing the unevenness?

For a 0.05 density difference or less I don't consider it significant
regardless of the cause and simply ignore it. There are simply too many
variables in photography to pursure that sort of exactness IMO and experience.

Tom Phillips wrote

Wouldn't it need to be aligned with Polaris to be in perfect "magnetic
balance"? Accounting for declination, of course...

Our favorite two poles are disintegrating. A third pole has appeared
two or three thousand miles from the present South pole. Several other
polar regions have appeared. That from a recent Nova program on PBS.
Perhaps a celestial "balance" would be better. Dan

LABFIX 2 wrote:

Jean-David Beyer wrote;
I always use a stop bath. What is the reason for avoiding it?

LABFIX2 wrote;
I have seen it cause a blotchy appearance, mosy evident with high key
backgrounds.

Jean-David Beyer wrote;
That is very unlikely.

Maybe I should have my eyes checked. And the other 4 photographers that saw the
test.

What is being questioning isn't what you saw, but what may have caused it.
Chemcially, stop bath won't in and of itself cause "blotchy" anything. Using water
or too weak a stop, possibly, or some other unknown. I habitually use a somewhat
stronger stop with the Jobo.

You weren't too technically specific, thus people question. This is a discussion
group...

Labfix2 wrote;

The volume listed on the tank only indicates the amount of chemistry needed to

cover the film. You may need to use more than indicated. (especially with b&w

diluted developers)

Jean-David Beyer wrote;
I am not convinced of that. I cannot imagine anyone used a developer
until the last few ions are depleted.

whatever...I'm not trying to convince you of anything.
It's been several years since trying to help folks with processing problems on
these newsgroups. Now I remember why I left. My suggestions were for people
having problems. If your processing methods work FOR YOU, don't change them.
Simple enough. I'll check back in a couple years.

You're both about half right. Yes, it's generally (I think) a good idea to use
more than the minimum. No, the developer dilution shouldn't matter since
regardless you develop to a specific CI using your own time.

2. If you are processing B&W, do not use a stop bath between dev and fix.

Why not?

I have seen the use of a stop bath cause a blotchy appearance. Most easily seen
with high key backgrounds.

Jean-David Beyer wrote;
2500 drums with 2509N reels work fine for me, and give even development.

Good for you!

I always use a stop bath. What is the reason for avoiding it?

I have seen it cause a blotchy appearance, mosy evident with high key
backgrounds.

I use fairly soft tap water for everything except mixing up PhotoFlo

If it ain't broke, don't fix it.

I am sure I have read those instructions. But they varied over time.

Yes they have. So have films and developers. JOBO has a excellent website that
will allow you to find out the most recent suggested procedures.

They recommend using enough
chemistry, and I use what they say on each tank.

The volume listed on the tank only indicates the amount of chemistry needed to
cover the film. You may need to use more than indicated. (especially with b&w
diluted developers)

I get uniform repeatable results with what I have.

My suggestions were for people who are having problems. If you get uniform
repeatable results, then keep doing what your doing. Cheers!

LABFIX 2 wrote:
Jean-David Beyer wrote;

2500 drums with 2509N reels work fine for me, and give even development.


Good for you!


I always use a stop bath. What is the reason for avoiding it?


I have seen it cause a blotchy appearance, mosy evident with high key
backgrounds.

That is very unlikely. It seems to me that, since an acid stop bath
stops development by neutralization of the developer much more rapidly
than a water bath would do it by dilution, that a stop bath is more
likely to be free of blotchy appearance than a water bath would be.

And if you skip the stop altogether and go direct from the developer to
the fixer, that is really no different from using a stop bath (if you
use an acid fix likd F5, F6, etc.) other than compromising the life of
the fixer and risking stains. But if you use the fix one-shot, you would
not care about the life.

I use fairly soft tap water for everything except mixing up PhotoFlo


If it ain't broke, don't fix it.


I am sure I have read those instructions. But they varied over time.


Yes they have. So have films and developers. JOBO has a excellent website that
will allow you to find out the most recent suggested procedures.


They recommend using enough
chemistry, and I use what they say on each tank.


The volume listed on the tank only indicates the amount of chemistry needed to
cover the film. You may need to use more than indicated. (especially with b&w
diluted developers)

I am not convinced of that. I cannot imagine anyone used a developer
until the last few ions are depleted. So if the developer is "too
dilute" you just need to develop longer. This should all come out in the
calibrations. In any case, except when I was testing someone's theory of
compensation (shown to be incorrect), I tried HC-110 1+31 from syrup,
1+63, and 1+127 and they all developped the film just fine if I
developped for the appropriate times. They did not diddle the shape of
the film curves (4147 and 4164 Kodak films) as suggested by that
someone's theory. I do not know if you consider HC-110 B diluted 1+3
with water to be all that dilute or not, but that is about as far as I go.

I get uniform repeatable results with what I have.


My suggestions were for people who are having problems. If you get uniform
repeatable results, then keep doing what your doing. Cheers!

OK: I hope your suggestions are helpful. I have more trouble with people
who say you cannot get uniform repeatable results with a rotary
processor, or Jobo rotary processors in particular. Maybe they cannot.

Let's see: if it is not the earth's magnetic field, is it the phase of
the moon? the sign of the Zodiac? ... ;-)

--
.~. Jean-David Beyer Registered Linux User 85642.
/V\ Registered Machine 73926.
/( )\ Shrewsbury, New Jersey http://counter.li.org
^^-^^ 8:15am up 19 days, 19:40, 2 users, load average: 2.30, 2.26, 2.19

I think the reason why many people here say that they have even development
is that they are either shooting and processing scenes with uneven,
irregular backgrounds which essentially camouflage any un evenness, or they
are not perceptive enough to see a difference.

Let me explain those statements. First, in most cases on my earlier
landscape work, I see very little un eveness except in the event of a very
even sky. However when the subject matter switches to large even white
backgrounds, the un evenness is very evident.

In regards to perception. I remember talking to the technicians from Sinar
about the fact that my expolux shutter was really only accurate in 1/3 stop
increments and not in the 1/4 stop increments that were stated in the Sinar
brochure. I was told that the motors needed to move a diapraghm
consistently to an opening as small as f32 or 45, could not be counted on
for that degree of accuracy in 1/4 stop increments. Fair enough. However
they went on to say that most people can not discern any differences greater
than 1/3 of a stop anyway. This last part blew me away. Every photographer I
knew in NYC, either bracketed in 1/4s or push/pulled in 1/4s and it was a
very obvious difference to all those I knew, In fact my own e-6 processing
was processed in 1/8 stop increments and that difference was clearly
discernible to me. Were the Sinar techs lying or in error? Or is it true
that most people can not discern differences smaller than 1/3 stop?

Maybe some of those reporting even processing, that have not used
densitometers, are simply not seeing the unevenness?

Brian Kosoff wrote:
I think the reason why many people here say that they have even
development is that they are either shooting and processing scenes
with uneven, irregular backgrounds which essentially camouflage any
un evenness, or they are not perceptive enough to see a difference.

I am not convinced. It is usually true that if I point a camera
somewhere, that what is photographed is not all that even, and the
unevenness of the subject matter can conceal unevenness of emulsion over
the size of the negative (I have never seen that, and imagine it does
not occur), unevenness of processing, etc. But the opposite is true,
too; some people photograph something like an "even" sky and see a
variation. I notice that the sky, even a clear blue sky, is not all that
even in practice; at least here in New Jersey. What appears even can
vary quite a bit if you actually measure it with a spot meter. It is
pretty obvious on the ground glass, too, if you use something like a
90mm lens on 4x5. So just as unevenness in processing can be obscured by
unevenness in subject matter, so also unnoticed unevenness in subject
matter can mistakenly appear to be the result of uneven processing.

I would never use actual negatives (or transparancies) of real subjects
to evaluate evenness in processing. For measuring uniformity of
processing, you need a means of making uniformly exposed negatives.
While not trivial, anyone who is processing his own films is probably
able to come up with a means of making such negatives.

When I used 6 sheets in the obsolete Jobo reels, the stripe down the
middle was about 1/2" or a little more wide and about one zone more
dense that the rest of the negative, it was obvious. It would take a
very complicated subject to mask that kind of thing.

Let me explain those statements. First, in most cases on my earlier
landscape work, I see very little un eveness except in the event of a
very even sky. However when the subject matter switches to large even
white backgrounds, the un evenness is very evident.

In regards to perception. I remember talking to the technicians from
Sinar about the fact that my expolux shutter was really only accurate
in 1/3 stop increments and not in the 1/4 stop increments that were
stated in the Sinar brochure. I was told that the motors needed to
move a diapraghm consistently to an opening as small as f32 or 45,
could not be counted on for that degree of accuracy in 1/4 stop
increments. Fair enough. However they went on to say that most people
can not discern any differences greater than 1/3 of a stop anyway.
This last part blew me away.

Not me. I think you and the technicians are talking about two different
things. The average user shoots negative film and generally a 1/4 stop
error in exposure is not that big a deal. If there were unevenness of
development in a single negative of 1/4 stop in an even subject, though,
that could be readily perceived.

Every photographer I knew in NYC, either
bracketed in 1/4s or push/pulled in 1/4s and it was a very obvious
difference to all those I knew,

Of course, with transparancy films, you do not get much chance to fix
exposure errors in the printing step since there is no printing step.

In fact my own e-6 processing was
processed in 1/8 stop increments and that difference was clearly
discernible to me. Were the Sinar techs lying or in error?

As I say, I suspect they were neither lying nor in error; they were not
talking about just what you thought they were. But you are neither lying
nor in error either.

Or is it
true that most people can not discern differences smaller than 1/3
stop?

When I was testing my E-6 processing, with an interest in re-using the
chemistry one time, I wanted to see the development time increase
required for the second run. The time specified by the processing
chemistry did not seem correct. I never finished that testing, but I did
notice some things. One is how bad the human eye is in evaluating
exposure (no kidding: that is why we use light meters). I made two runs,
the second using the manufacturer's recommended time increase. The two
transparancies (exposed one right after the other) looked the same to
the naked eye. Putting them on a densitometer revealed great difference
(part of the subject was a reflecting step wedge). I forget the amount,
but perhaps 0.2 density unit. Now IMAO that is really bad processing, I
would say. But looking at either transparancy by itself looked fine.

OTOH, presented with an image where one half receives 1/3 more exposure
than the other is clearly discernable with the naked eye. The eye is
very sensitive to differences, especially with respect to things right
next to each other, but not very sensitive to absolute values.

Maybe some of those reporting even processing, that have not used
densitometers, are simply not seeing the unevenness?

Possibly. But surely some of the users (e.g., John Sexton) would be
extremely sensitive to such problems and would have quit using their
Jobo equipment long since.


--
.~. Jean-David Beyer Registered Linux User 85642.
/V\ Registered Machine 73926.
/( )\ Shrewsbury, New Jersey http://counter.li.org
^^-^^ 9:10am up 19 days, 20:35, 2 users, load average: 2.26, 2.12, 2.10