Weird surge marks / banding on C-41 film

[zen_zanon]

So I'm getting these weird streaks that are most apparent in the sky of my home-developed C-41 film. It has appeared on both expired Kodak Portra VC and fresh Fuji 160NS. It is apparent on the negatives and is visible both in and outside of the image frame. It doesn't seem to be consistent across the whole roll...as some images don't seem to have it at all. I haven't seen this on the 30+ rolls of E6 I've developed using my same setup.

Developing Details

• Paterson tank with plastic easy load reels
• Waterbath @ 38C maintained by a sous vide and monitored with a second thermometer
• Tetenal Colortech C-41 kit
• Developer and Blix agitation for first 30s and then 2 twists of the agitation stick every 15s
• Constant agitation during Stabalizer

Right now I'm thinking it could be one of two things:

1. Streaks caused by drying. If this is the case, can I rewash the film? If so, how do I do this and what should I use?
2. Streaks caused by agitation?

Any help would be greatly appreciated. Examples below from 6x4.5 120 film below.

 

[Kino]

Is the agitation totally via the agitation stick without any inversions? If so, I would think you need to add more random movement to the agitation. It could be directional effects from the developer waste products stratifying in the tank...

 

[zen_zanon]

Is the agitation totally via the agitation stick without any inversions? If so, I would think you need to add more random movement to the agitation. It could be directional effects from the developer waste products stratifying in the tank...

Thanks for your thoughts! Yes all agitation is done via the agitation stick. I would think that you're on to something, but as you can tell in my examples, the streaks seem to be happening 90 degrees to eachother. My first example is a landscape orientation 6x4.5 frame with vertical streaks while my second example is a portrait orientation 6x4.5, also with vertical streaks.

 

[Kino]

Forget that last comment; I'll bet its scanning artifacts...

Check the negs with a loupe.

 

[Kino]

Density streaks or water marks in the negs should be visible.

What scanner are you using? Any glass involved in the holders? Does the glass have any hint of fogginess on the scanner bed?

I ask because my Epson 4990 suffers from out gassing of the plastic and it forms a very similar pattern of light haze on the inside surface of the platten glass that must be cleaned at least once a year.

 

[zen_zanon]

Forget that last comment; I'll bet its scanning artifacts...

Check the negs with a loupe.

It's on the negs and I'm scanning with my Sony A7 and macro lens. Haven't had scanning artifacts yet with this method. No glass surfaces involved as the negs are floating in a holder about ~2" above a light source.

 

[Kino]

Are the two opposing direction streak shots on the same roll? Grasping at straws here...

 

[Kino]

You can rewash the film by simply redeveloping the film at the standard time/temp, using fresh chemistry.

 

[WilmarcoImaging]

Two ideas. First, artifacts or residue from chemical carryover between baths, or chemicals that are not full strength for whatever reason (exhaustion, carryover). Do you use a rinse between baths? Can you describe your pouring regimen? Exactly how fresh are the chemicals for the images shown?

Second is a pouring artifact from developer streaking down the film as it is poured in the tank. How is the developer poured into the tank? There are ways to control the flow of liquid smoothly into the tank.

Do you use a pre-wet bath?

 

[zen_zanon]

Are the two opposing direction streak shots on the same roll? Grasping at straws here...

Yes they are from the same roll.

Two ideas. First, artifacts or residue from chemical carryover between baths, or chemicals that are not full strength for whatever reason (exhaustion, carryover). Do you use a rinse between baths? Can you describe your pouring regimen? Exactly how fresh are the chemicals for the images shown?

Second is a pouring artifact from developer streaking down the film as it is poured in the tank. How is the developer poured into the tank? There are ways to control the flow of liquid smoothly into the tank.

Do you use a pre-wet bath?

1. I do wash rinse between the color developer and blix bath. I was already planning on changing to rinsing next time I mix up fresh chems. The instructions didn't say to so I didn't, though in retrospect I see why it's a good idea to do so. I can't remember off-hand how fresh the chems would've been for these rolls (I did a bulk developing day and got through upwards of 20 rolls). I can say that this issue seems to persist throughout the day so I'm not sure exhausted chemicals are the answer.

2.) This may be an issue. I pour all chemicals into the hole of the patterson tank as reasonably quick as I can without causing overflow. When it comes time to pouring the chemicals out, I'd say it takes no more than 10s to empty the tank. I'm open to hearing ideas of controlling the flow of liquid.

Yes, I pre-wash until the pre-wash stops being colored (Portra VC is dark forest green!). Pre-wash usually is a few minutes at 38C and takes a couple times of fully filling and emptying the tank.

 

[MattKing]

The instructions for the Paterson tanks state that the agitation stick should be used, at most, for the first 30 seconds of any process.

 

[zen_zanon]

The instructions for the Paterson tanks state that the agitation stick should be used, at most, for the first 30 seconds of any process.

Hmm, plenty of people seem to not have issues with this. I guess that could be it though?

God inverting every 15s while using a waterbath sounds terrible.

 

[Bob Carnie]

These are minis density marks on the negative, I have seen this issue in my own work ant that of others... Lack of Agitation in the first 15-20 seconds... We invert and twist when these things come up even on Jobo, Happens mostly in flat areas of Image, you will not see them in complex areas of an image, and this actually is a bigger problem than most people think.

 

[zen_zanon]

These are minis density marks on the negative, I have seen this issue in my own work ant that of others... Lack of Agitation in the first 15-20 seconds... We invert and twist when these things come up even on Jobo, Happens mostly in flat areas of Image, you will not see them in complex areas of an image, and this actually is a bigger problem than most people think.

Interesting! Could this be an issue that occurs while chemicals are still being poured? I'm pretty quick to get the initial 30s of agitation going with the agitation stick. Also, this is lack of agitation in what step? The developer or blix?

 

[michaelfoto]

Had similar problems only using Jobo tank instead of Paterson. Then i noticed that Jobo does not recommend prewash. Instead you heat the tank with film in it in the water bath for 5 to 10 minutes and proceed normally after that. That helped a lot, and i hardly see these artifacts anymore.
Worth a try, and the coloring of your chemicals will not be harmful.
Michael.

 

[georgegrosu]

The defect of negative you see like zZ6Yxqa NEG.jpeg (attached)?

Everyone's way of working differs (agitation and others).
Probably every work variant has advantages and disadvantages.
Perhaps it is important to choose the smallest evil.
Everyone is free to choose what he wants.
Prewash does not seem to do any harm to the film if it does not dilute the developer or change its temperature.
It's a simple opinion of mine.
I do not use C 41 or E 6 kits.
For the negative color I use the ECN 2 process, and for the color slide I have a process of mine, compatible with E 6.
For color processes (negative or slide), agitation in the Krokus tank is moderate and continuous.
Fill the Krokus tank with the developer, bring it to the required temperature and in the dark, place the roll of film in the developer.
Agitation makes it in the dark, without the tank cover.
Developer do not reuse them.
Removing the developer is quick.

You can see something theory here as well.
https://www.photrio.com/forum/threads/development-defects-that-may-appear-on-the-films.146152/

 

[Bob Carnie]

Interesting! Could this be an issue that occurs while chemicals are still being poured? I'm pretty quick to get the initial 30s of agitation going with the agitation stick. Also, this is lack of agitation in what step? The developer or blix?

Both

You have to be fast with your pour and you need to allocate all the chemicals across all the film surfaces evenly and as fast , what you are seeing is gaps where the film is being less developed and therefore printing darker . This drove my lab nuts for a month until we initiated a manual pour , twist and inversion on film with any large nuetral areas like sky or grey backdrops in scene. Landscapes within a tree line are so complicated for example you would never see these marks, only in open flat areas.