C41 Digibase kit issues

Dear all

 

I am having a real issue with my 35mm negs. An example of my issue is attached. I am using Digibase kit and developing at 30 degrees.

 

• The chemical mix is correct (results are fine with 120)
  
• my hygiene between processes is fine
  
• The temperature is constant 30 degrees
  
• I get the same issue with an in version every 30 seconds or when I use a constant slow rotation
  

Sprocket holes seem to be the focus of the issue but no idea how to stop this. When I first started C41 develping I had none of this issue!. Really starting to run out of options..

 

Any thoughts or help appreciated

 

Dear all

 

I am having a real issue with my 35mm negs. An example of my issue is attached. I am using Digibase kit and developing at 30 degrees.

 

• The chemical mix is correct (results are fine with 120)
  
• my hygiene between processes is fine
  
• The temperature is constant 30 degrees
  
• I get the same issue with an in version every 30 seconds or when I use a constant slow rotation
  

Sprocket holes seem to be the focus of the issue but no idea how to stop this. When I first started C41 develping I had none of this issue!. Really starting to run out of options..

 

Any thoughts or help appreciated

 

[ATTACH=full]1243641[/ATTACH]

 

Is the problem with any 35mm negs or just ones from a particular camera? Just asking since 120 seems to be fine. The only thing I've ever experienced that was similar was a light leak but it was just a single streak.

Since this is a negative film and you are displaying a positive image, the streak bands are plus density on the film. Additionally the streaks seem to be associated with the sprocket holes native to 35mm film. Further, the streaks start out narrow at the top of the image and then transverse the film getting wider as they go.

 

 

Looks to me like a light leak coming from bottom rear of the hinged film access door. Bottom because the camera lens inverts the image. It is inconclusive that this fogging occurred in the camera, or in the darkroom. The reverse side of film has an anti-halation coat. It is not completely opaque but it has enough density to protect the film from a feeble accidental light exposure. The sprocket holes provide no such protection, thus an accidental exposure from the rear appears as if the sprocket holes are the origin. I have seen similar fog patterns due to improper light proofing of the darkroom, light leaking into the developing tank, and/or X-ray exposure at the airport inspection.

 

 

I have also seen streaking induced by improper agitation of the film. The sprocket holes can encourage fluid turbulence that appears as streaking coming from the sprocket holes. The countermeasure is; initially continuous agitation for 30 seconds followed by 5 seconds of agitation every 30 seconds.

 

 

My bet is a camera seal leak. Procure a tiny keychain flashlight, one that stays lit when activated. Place this light inside the camera and close the camera back. Now withdraw to a totally dark room and sit for 15 or 20 minutes with the camera in your lap. It takes this long for your eyes to adapt. Now look at the camera from all viewpoints. If the seals are leaking you will see light leaking out. In other words, under normal conditions, the dark can leak out of your camera!

Thanks Alan - the images were shot with a recently serviced leica IIIc. I have use BW film through this camera many times with fine results and no light leaks. I have attached another shot (negative) from the same film that shows related marks

 

Either your agitation is too aggressive, or maybe your film is not wound quite right on the reel.