Kindly help debug my negative (again)

RoboRepublic

Subscriber
Joined
Mar 25, 2020
Messages
614
Location
Boston
Format
Medium Format
What on earth is causing these circular patterns at the top of the frame?

I use Jobo 1540 tanks. This example here is TMY 400 ISO400 HC110 for 13 minutes at 68 degrees. I do a 1 minute anti-halation pre-wash. 2 gentle inversions at the top of the minute.

My notes say that this particular roll was in the *bottom* reel. Both rolls in the bottom and top exhibit this problem. This problem occurs in about 4/5s of all rolls I develop.

4th frame in a 6 frame sequence (6x12 camera).

Thanks!
 

Attachments

  • 22.05.06.SW612.90mm.TMY400.ISO400.HC110_H.Plustek.NB_Akira_03 1.jpg
    1.7 MB · Views: 131

AgX

Member
Joined
Apr 5, 2007
Messages
29,973
Location
Germany
Format
Multi Format
Debugging a negative would necessitate an insectiside.
 

foc

Subscriber
Joined
Jun 30, 2010
Messages
2,525
Location
Sligo, Ireland
Format
35mm
From what I can gather, you are developing 120 film, is that correct?
From a quick look at your image, I would think that the marks are from air bubbles.

Can you upload an image of your negative, please (the same as the positive image you have uploaded)
Something like this.
 

Attachments

  • IMG_48362.jpg
    24.8 KB · Views: 57

AgX

Member
Joined
Apr 5, 2007
Messages
29,973
Location
Germany
Format
Multi Format
Yes, air bubbles are the most likely cause.
 

Nicholas Lindan

Advertiser
Advertiser
Joined
Sep 2, 2006
Messages
4,249
Location
Cleveland, Ohio
Format
Multi Format
Follow Kodak's agitation instructions and the problem should go away. Rap the tank firmly several times after filling to dislodge the bubbles. 5 inversions in 5 seconds every 30 seconds for agitation.

When starting out in photography I followed the instructions to the letter and things turned out OK. Then I decided I knew better and pursued every developing protocol under the sun and things generally went downhill. Then I went back to following the instructions and things started turning out OK again.
 

Sirius Glass

Subscriber
Joined
Jan 18, 2007
Messages
50,411
Location
Southern California
Format
Multi Format
Air bells, you need to give the tank one or a few hard raps when each chemical is poured into the tank.
 

gone

Member
Joined
Jun 14, 2009
Messages
5,504
Location
gone
Format
Medium Format
What Sirius said. I bonk the tank now and then during all of the developing and fixing, no need to during the wash. I'm surprised I haven't cracked the tank, but I do try to mitigate that by knocking the bottom of the tank onto a piece of wood on the counter that has a few washcloths around it.

For a while I was having a spate of developing issues and finally went back to straining the chemicals through a couple of coffee filters. That fixed things. It doesn't take much time, and eliminates a big variable.
 

Patrick Robert James

Member
Joined
Jul 31, 2012
Messages
3,362
Format
35mm RF
JOBO reels are prone to this with 120 film and inversion processing. Bubbles get trapped between the film and the edge of the reel and there is no where for them to go. The best way to eliminate the bubbles is to use a drop or two of Edwal LFN in the developer. Prewetting will also help. When you fill the tank, fill it at an angle. It also will help to use aggressive agitation at first. The design of the JOBO 1500 system doesn't allow the reels to move on the stalk. Other plastic systems are like that too but the reel designs are different. You rarely see bubbles on metal reels because they easily move around in the tank which dislodges any bubbles that form. Whacking the tank with the JOBO doesn't work all that well. I'm an almost 30 year JOBO user so I just know from experience. You can whack all you want but the bubbles are trapped in there.

I just noticed you use HC110. You might not be able to use LFN with that. I've had issues with Pyrocat mixed in Propylene Glycol. The combination of the Glycol and the LFN turns the developer into a bubble bath. LFN works great with every other developer I've tried though.

Keep in mind the JOBO system was designed for roller processing. I think the design of the reels isn't the greatest if you don't process that way. With roller processing the developer is always moving through the reels dislodging any bubbles that form. Not so with inversion processing.

Hope that helps you.
 

Sirius Glass

Subscriber
Joined
Jan 18, 2007
Messages
50,411
Location
Southern California
Format
Multi Format
Sirius Glass said:
Air bells, you need to give the tank one or a few hard raps when each chemical is poured into the tank.
Click to expand...

When I thunk the tank I thunk it on a block of rubber.

I think that Jobo tanks were designed for their rotary processors, not inversion.
 

MattKing

Moderator
Moderator
Joined
Apr 24, 2005
Messages
53,262
Location
Delta, BC Canada
Format
Medium Format
After the "thumps" recommended above, you might consider giving the film its first 30 seconds of agitation by rolling the tank continuously by hand on a flat surface or a roller agitator (which is what I do).
 

bernard_L

Member
Joined
Feb 17, 2008
Messages
2,055
Format
Multi Format
Been there. For decades, have been knocking the tank and all went well. Then, since maybe 2 years, started to have these air bells. Despite the knocking. A change in the water distribution maybe (I use de-mineralized water only for the final Photo-Flo rinse).
Following advice on Photrio, added 50cc to the dev volume, i.e. 500-->550cc for 120 film in a Paterson reel (YMMV). This cured the problem.
Also once I followed advice by (IIRC) Ian Grant: add a couple drops (less than for final rinse) Photo-Flo in the dev to promote wetting of the film surface. It worked, bu I feel uneasy about adding to the dev something that... promotes the formation of bubbles.
 

Sirius Glass

Subscriber
Joined
Jan 18, 2007
Messages
50,411
Location
Southern California
Format
Multi Format

In any type of tank, adding 50 cc can cure air bells.
 

Bill Burk

Subscriber
Joined
Feb 9, 2010
Messages
9,327
Format
4x5 Format
Paterson tank? Used the measure of chemicals embossed on the bottom? @Sirius Glass is right - fill that tank up.

Also you should rap the tank so hard that you think you might break it. (sincere)

You won’t break it because they are tough.

(snarky) But if you do, replace it with steel tank and reels.
 

NB23

Member
Joined
Jul 26, 2009
Messages
4,307
Format
35mm

I broke one, once. It split in two...
 

AgX

Member
Joined
Apr 5, 2007
Messages
29,973
Location
Germany
Format
Multi Format
bernard_L said:
Been there. For decades, have been knocking the tank and all went well. Then, since maybe 2 years, started to have these air bells. Despite the knocking.
Click to expand...


Seems enigmatic. The only idea that comes to my mind is change of developer composition. I do not see how a change from tap to demineralized water could have caused this.
 

bernard_L

Member
Joined
Feb 17, 2008
Messages
2,055
Format
Multi Format
AgX said:
I do not see how a change from tap to demineralized water could have caused this.
Click to expand...
bernard_L said:
I use de-mineralized water only for the final Photo-Flo rinse
Click to expand...
which means I use tap water for everything else, including mixing the developer. Whether that is Officially Approved may be debatable (the Kodak instructions for mixing clearly show a faucet), but is outside the scope of this thread.
 

AgX

Member
Joined
Apr 5, 2007
Messages
29,973
Location
Germany
Format
Multi Format
The industry standard for mixing developer and anything else is tap water.
 

foc

Subscriber
Joined
Jun 30, 2010
Messages
2,525
Location
Sligo, Ireland
Format
35mm
I have used tap water for mixing all my chemicals, both privately and when I worked professionally and I never had one film with air bubbles. I followed a few simple steps and it seemed to work for me.

  • Stir your mixing water in the graduated cylinder to dislodge any air bubbles in the water. Some taps/faucets can cause water to froth.
  • Mix more than the recommended tank volume. If the tank says 280ml then mix 300ml.
  • Pour in the developer quickly and gently tap the tank. I never used pre-wash
  • I have used "the wine swirl" form of agitation for the last 4 decades and it worked for me.
Hope this might be of some help.
 
You must log in or register to reply here.
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…