Fine scratches in E6 sheet film processed in Jobo
Since my last nearby E6 lab closed down, I have begun processing my own E6 film in a 3010 Expert drum and a Jobo CPA2 processor. So far so good thanks to the great advice I have received in answer to my questions here. I developed some 4x5" Velvia 50 today and everything looks fine except for one thing and I wonder if anyone here has experienced it too. The film has many tiny scratches in it which can be seen when just held up to a light for viewing with a lupe. However, those scratches are not visible when I view them on a light table (diffused light source). For the most part, the scratches tend to go across the short dimension of the film, i.e. in the same direction that the chemicals would pass over the film while processing. Some of them do bend and turn, though, but the pattern is clear... the scratches are mostly across the 4" dimension. They can't be seen in detailed parts of the image but they are easily seen in large, uniform light areas - like the sky, etc.
For comparison, I took out some film that had been processed by my old lab in their dip & dunk line. There are some similar fine scratches on some of the lab processed film but not nearly as much as on the film that I processed. Also, the scratches on the lab-processed film seem more random in direction. I don't think the scratches I am getting will cause problems, though, because I did a couple fairly high-resolution scans and the scratches didn't show up in them. But I still would like to reduce or eliminate the scratches. I am not sure how they are getting there. I have been processing b&w sheet film in trays for four decades and have never seen this with b&w film. In fact, I can't remember the last time I had a defect in my b&w film at all. The reason I mention this is that I am obviously handling the b&w film much more when tray processing but I literally never get scratches with b&w film. Maybe E6 film is more delicate?
I load the film carefully (dry) into my 3010 drum. For this run, I used my regular tap water, which is good. The water passes through a 2 micron filter just before being used. My water is perfectly clear with no visible particulate matter in it. The reason I mention this is that, as I said, the scratches mostly go in the direction that the chemicals pass over the film in the drum and it almost looks as if there was a fine abrasive in the chemicals by the direction of the scratches.
Film from my previous test run had much fewer fine scratches on it. I just this minute thought of something that may explain the scratches I got today but I am going to post this question anyway.... With my last test batch, I did the stabilizer step (mixed in distilled water) one sheet at a time in a tray. This time I did eight sheets all at the same time, carefully shuffling through the stack as I would when tray processing. I did that simply to save time because these were just test shots that I will throw away. That type of agitation would not scratch b&w film but perhaps E5 films are much more delicate? Also, if they were scratched in the stabilizer, the scratches should have gone along the long dimension of the film because of the way I agitate.
I would appreciate any advice you may have, especially if you have had a similar problem yourself.
No, the E6 film - and especially the sheet kind of them - is virtually bulletproof. The scratches are coming, I think, definitely not from Jobo and your processing, but from some abrasive particles - either between the sheets of film in box, or more probably from your tap water. I never get any scratches alike on my E6 films in 35, 120 and sheet formats - so look for the potential source of the abrasives in your system. I am more than sure that it happens when the film is dry - in box, or somewhere else, Jobo is not guilty at all The moist E6 emulsion is VERY sturdy - multiple passages of drying squegee don't do any harm, so it's nearly impossible for fine particulate matter suspended in E6 chemistry to make such abrasions.
Thanks, eumenius. Knowing that the film is virtually bulletproof will help me diagnose the problem. I knew it wasn't the JOBO, of course. The JOBO never even entered my mind as being the culprit. The emulsion side of the film never even touches the tank although I'm not sure whether the scratches are on the emulsion side or the base side. I had assumed that they were on the emulsion side but it's possible that they are on the base side. I will see if I can determine which side they are on. I suppose I could coat a bit of each side with, say, a highlighting pen and see which side shows that the color has been absorbed into the scratches. I'll mess with that later today. If the scratches are on the base side, then I guess it would be possible that the scratches happened when the film was inserted into the drum but I doubt that as well. The drum was perfectly clean and the fine scratches are distributed evenly over the surface of the film and are directional across the short dimension. If they were caused when loading them into the drum, the scratches would run along the lengthwise dimension of the film since the film slides in that way. I left about an inch sticking out above the tubes until all the film is loaded.
Keep in mind that the scratches are not visible at all when the transparencies are viewed on a light table. If you only view your film on a light table, you would never see any scratches like this on your film even if they were there and you wouldn't see them in detailed or darker areas either. If I hadn't held them up to a light and viewed them with a lupe when I took them out of the drier, I would never have known the scratches were there. Normally, I just view them on a light table.
As for my tap water, I don't think that's the culprit. As I said, I have very finely filtered (2 micron) water. It is perfectly clear with absolutely no visible particulate matter in it at all. Besides, I have never had this problem with b&w film even when using my water without being filtered. I also have doubts that the scratches are occurring when the film is dry. If the film is bulletproof when it is wet, it is even more bulletproof when it is dry. All films are most vulnerable to scratches when they are wet, of course. I never squeegee film. I just hang it in my film dryer. Of course, it's possible that the film was defective as it came from Fuji, but that is highly unlikely as well. But I will keep that in mind and see if the problem persists with I use film from other boxes. Thanks for pointing out that possibility. My other boxes of film are from a different batch number.
My best guess at this point is that the scratches occurred during the stabilizer step. Although I used distilled water for that step, there is a possibility that there was something in the tray that became suspended in the stabilizer. But, again, that is unlikely as well because I always clean my trays very well after using them and I rinse them before using them just to make sure there is no dust, etc. in them. It's just a habit I have from over 40 years of processing film in trays. Also, even if there were particles in that tray, I don't rub the film together anyway. But I was not as careful when I agitated them in the stabilizer this time because they were just test shots that I was going to throw away anyway. That's the step I will change next time. I will stabilize each sheet separately and see what the results are. As I mentioned, the last batch that I processed (which was my first batch with the JOBO), did not have those scratches - well, they had a few but not nearly as many. The only difference between the way I processed the two batches was that I stabilized each sheet separately with the first batch.
Again, thanks for the info. I will keep it in mind as I try to diagnose the problem. Your suggestions helped me to think this though better. Sorry for rambling out loud here but, by doing so, someone may have additional suggestions since they will know my process better.
Last edited by ZoneIII; 04-15-2008 at 10:16 AM. Click to view previous post history.
One of the reasons for such scratches, when these are on the base side, can be some sand/enamel irregularities in film holder, but usually the scratches from this will run directionally across the longer side. The stabilizer is also not an option, for my taste - obviously both side of the film will be scratched if it happens in your tray (by the way, is the tray's bottom smooth enough?). I think that perhaps the film was scratched from the very beginning, maybe due to some friction in the box, but it's HIGHLY unlikely for Fuji's quality pro film.
I use the distilled water for all E6 solutions, and a well-filtered tap water for anything else like final washing of film before stabilization - and I never ever had a single scratch on my film. More, I always wonder how beautifully shiny are those E6 films when moist Try to understand which side is scratched - I think it's the base side. Try to light a laser pointer and hold it at a very acute angle to film's surface - that will help you to observe any irregularity easier.