I have been getting streaks or marks on my Holga negatives which are sometimes yellow or magenta. They look like they are the result of uneven development, or sometimes I think that not all the CD or Blix has been washed off the negatives- though that would leave a residue on the negative which is absent.
I noticed last night that I only get streaks or discolouration on films shot with my holgas. Films shot with my Mamiya 6 come out fine with no marks at all and all the films are processed together, so I do not think that the marks have anything to do with agitation or temperature etc. I agitate properly (30s continuous and 5s every 30s) and maintain the temperature constant at 38C.
Interestingly, I processed a batch of b&w films with Dixactol for the first time over the week end. Those films shot with the Mamiya 6 are perfect, but the films shot with a holga have drag marks on them. Again, these films were processed together, so I don't think the difference is due to my processing technique because if it was I'd get the same marks on all the negatives.
Negatives shot with the holga will be underexposed (f11 at 1/100 approx.) compared to the Mamiya negs which will be properly exposed so I am wondering if I shouldn't manipulate either the colour developer or blix times to compensate.
I have read that increasing the development times of the CD will cause colour shifts and I am not sure whether or not increasing the blix time will do anything.
Does anyone have any suggestions or has had a similar experience. Is there a way to change the C41 process that will produce flawless negatives from my holgas?