Still have bubbles on the roll film

I thought I'd ask this question again, as I've never really resolved
it, and there might be something I'm still unaware of.

Despite a two minute prewet, and a good hard tap of the tank after
every agitation I still will find minus density globs, on the edges of
the film.
I've taken to putting the skies downward, as the globs usually are on
the up edge of the reel. These are Paterson, and it happens with any
developer.They are globs, not perfectly round bubbles, and occure not
the full length of the 120 film, but tend to the middle four or five
images. Exasperating indeed.

Ken Smith wrote:
I thought I'd ask this question again, as I've never really resolved
it, and there might be something I'm still unaware of.

Despite a two minute prewet, and a good hard tap of the tank after
every agitation I still will find minus density globs, on the edges of
the film.
I've taken to putting the skies downward, as the globs usually are on
the up edge of the reel. These are Paterson, and it happens with any
developer.They are globs, not perfectly round bubbles, and occure not
the full length of the 120 film, but tend to the middle four or five
images. Exasperating indeed.

Try _without_ the pre-soak. Atleast Ilford recommends not to presoak
because of anti-foaming coatings. Try without pre-soak and maybe you'll get
rid of the bubbles - and a useless step in processing

Severi S.

I have had the same problem in the past when I worked for a guy that had
Paterson equipment (could not load a ss reel to save his life). No amount
of inversion ever eliminated the problem.
And I broke a couple of tanks trying to bang them hard enough to dislodge
the bubbles.

Then when cleaning the pit he called a darkroom one day I found one of the
little agitator rods that twist the reels back and forth.

I put a piece of rubber tubing over the end of the "swizzle stick" to give
me a better grip and started twisting the reels in the tank. 30 seconds
continuous at the start of the cycle and 5 seconds every 30 after that. The
bubbles went away.

--
darkroommike

----------
"Ken Smith" wrote in message
om...
I thought I'd ask this question again, as I've never really resolved
it, and there might be something I'm still unaware of.

Despite a two minute prewet, and a good hard tap of the tank after
every agitation I still will find minus density globs, on the edges of
the film.
I've taken to putting the skies downward, as the globs usually are on
the up edge of the reel. These are Paterson, and it happens with any
developer.They are globs, not perfectly round bubbles, and occure not
the full length of the 120 film, but tend to the middle four or five
images. Exasperating indeed.

Mike King wrote:

I put a piece of rubber tubing over the end of the "swizzle stick" to give
me a better grip and started twisting the reels in the tank. 30 seconds
continuous at the start of the cycle and 5 seconds every 30 after that. The
bubbles went away.

If you do this, make sure you wont end up getting streaks. I agitated first
with a rod only and the results were horrible. Now I do everything
"normally" (ie. as Kodak or Ilford recommends) and I get no streaking or
bubbles or pinholes.

Severi

I've been using for deacades a Jobo plastic tank and never (well, almost)
had bublle problems.

Just a guess:
I invert and twist the tank at the same time.

Jorge


(Ken Smith) wrote in news:eb5d68c1.0402061032.52fb5bf2
@posting.google.com:

I thought I'd ask this question again, as I've never really resolved
it, and there might be something I'm still unaware of.

Despite a two minute prewet, and a good hard tap of the tank after
every agitation I still will find minus density globs, on the edges of
the film.
I've taken to putting the skies downward, as the globs usually are on
the up edge of the reel. These are Paterson, and it happens with any
developer.They are globs, not perfectly round bubbles, and occure not
the full length of the 120 film, but tend to the middle four or five
images. Exasperating indeed.

"Mike King" wrote in message ...
I have had the same problem in the past when I worked for a guy that had
Paterson equipment (could not load a ss reel to save his life). No amount
of inversion ever eliminated the problem.
And I broke a couple of tanks trying to bang them hard enough to dislodge
the bubbles.

Then when cleaning the pit he called a darkroom one day I found one of the
little agitator rods that twist the reels back and forth.

I put a piece of rubber tubing over the end of the "swizzle stick" to give
me a better grip and started twisting the reels in the tank. 30 seconds
continuous at the start of the cycle and 5 seconds every 30 after that. The
bubbles went away.

--
darkroommike

----------

Wow, that's definitely never worked for me. Unless I invert it's
always been an uneven bonanza. I made up a bunch of PVC tubes with
caps at one time, and did everything in the dark. I still use them,
but have to keep the film in the Paterson tank for inversion. When
I go in the fix, I make sure to take the reels out, invert, and back
in again. I can't imagine a non-inversion film development not
producing streaks. Just goes to show you what kind of science THIS
is.

No system is perfect. However, I prefer Metal Reels and Tanks. The more
experienced photographer gurus that use Metal Reels & Tanks will still get an
occasional bubble every now and then.

Shaking the developing tank like a milk shake will obviously create new bubbles.

Are you filling the tank up to the top? I find that is a good way to avoid
bubbles as well.

Plastic reels are thicker than metal reels and the result of this is, more air
is trapped under the outer rims of the plastic reels. I also noticed that I was
getting more bubbles and thinner densities on the outer edges of my developed
films in plastic reels. Dry plastic in my opinion likes to catch bubbles.
Also, the thickness & width of the outer rim of the plastic reels also
contribute to the catching of bubbles. Not to mention that the developer
doesn't get under the plastic tracks of the film reels to give even development.
Plastic seems to dry immediately when a bubble makes contact with it. Which is
why wrapping the tank hard on a flat surface is critical to getting the bubbles
loose from the film.

Because the Jobo system offers continues movement they get better results then
manual systems. Jobo also has a problem with sprocket hole Dev-flow marks
because of the constant movement of the development tank.

Plastic Reels may be easier to load than metal reels but metal reels are thinner
and if used correctly, offer better results than plastic reels.

Also; Metal Tanks offer better temperature control than plastic tanks do.
Especially when you are talking about short development times of 4 & 5 minutes.
Plastic doesn't conduct temperature quite like metal does and the temperature
control is more difficult with plastic Tanks.

I am a big proponent of Metal Reels and Tanks for the aforementioned reasons.




"Ken Smith" wrote in message
om...
| I thought I'd ask this question again, as I've never really resolved
| it, and there might be something I'm still unaware of.
|
| Despite a two minute prewet, and a good hard tap of the tank after
| every agitation I still will find minus density globs, on the edges of
| the film.
| I've taken to putting the skies downward, as the globs usually are on
| the up edge of the reel. These are Paterson, and it happens with any
| developer.They are globs, not perfectly round bubbles, and occure not
| the full length of the 120 film, but tend to the middle four or five
| images. Exasperating indeed.

pour the developer into the tank a bit slower.....
Pouring the developer in quickly allows air bubbles to be carried
into the reel.

You need to pour the liquid in fast so that the film at the top gets the
same time especially in the developer (as close as possible) as the film at
the bottom of the tank. I find pouring from a height of about 25 cm seems
to get a stream into the tank quickly. It takes me about 15 sec to fill a
three 120 size spool tank. A solid bang on the table should dislodge all
air bubbles.

regards
Malcolm
wrote in message
...
pour the developer into the tank a bit slower.....
Pouring the developer in quickly allows air bubbles to be carried
into the reel.

"Malcolm Smith" wrote in message ...
You need to pour the liquid in fast so that the film at the top gets the
same time especially in the developer (as close as possible) as the film at
the bottom of the tank. I find pouring from a height of about 25 cm seems
to get a stream into the tank quickly. It takes me about 15 sec to fill a
three 120 size spool tank. A solid bang on the table should dislodge all
air bubbles.

regards
Malcolm
wrote in message
...
pour the developer into the tank a bit slower.....
Pouring the developer in quickly allows air bubbles to be carried
into the reel.


Actually, I work in the dark. The tank is full to start. Prewet, pull
after two minutes, drop in film dev., give a few swishes, cap on and
start first minute agitation.

Ken Smith