C41 failure - film, chemistry or user error?

[toni_nikkanen]

<p>I have processed some ~30 rolls of C41 film at home using Paterson Universal tanks and reels and the Tetenal C41 3-bath kits. Up to now I've had no problems whatsoever. Today I mixed a fresh set of Tetenal chemistry and developed one roll of Superia 800 as per the first time use - 3:15min 38C developing, 4:00min blixing, 3 minutes rinse. 1 minute in stab. I used one liter of each solution that fills my tank entirely.</p>

<p>Something about the film: I had shot it up to frame #26 using a Voigtländer Bessa R2A camera that has been working well before. Some frames were exposed manually, some with the builting TTL metering, some in bright outdoors, some in dim indoors and lots in between. Inside the film changing bag that I routinely use for getting the film on the reel I noticed already something weird - there was almost no curl in the film; it had no tendency of curling back into a roll. Also I fumbled something at first and then tried to get the film off the reel, but some of it got torn at around frame #22 - I cut the bad part away from the middle and successfully loaded the film parts on 2 reels. Thankfully I had two reels with me in the changing bag!</p>

<p>The problem: The film base is very thick and edge markings are hard to read as are the frames. I scanned two frames and in the scan the frame is very dark, just like underexposed or -developed. The odd part: At the end of the roll, somewhere around frame number #32 and until the end, the film appear perfectly normal, film base thickness looks like previous Superia 800 films I've developed and edge markings are easy to read. This does not make any sense to me at all since frames 1-31, even including the unexposed ones, have a very thick base with very hard to read edge markings.</p>

<p>So what is going on? The usual suspects are of course:<br>

a) user error (there definitely was some of this, but I don't see how it might have caused this problem)<br>

b) developer or blix is not working properly<br>

c) something wrong with the film - it might have been expired, though not by more than 2-3 years at most. It might have had a couple of x-rayings happen to it as well but still doesn't sound like a plausible explanation.<br>

Why the end of the film appears normal is what is confusing me the most here.</p>

<p>I tried re-blixing a piece of the film (for 10 minutes using the same blix as the first time) but it didn't seem to change anything.<br>

I might try to dip some of the film into Agefix next just for fun...</p>

<p> </p>

[toni_nikkanen]

<p>Agefixing didn't change anything either..</p>

<p>I guess I'll have to shoot a test roll of some safe unexpired not too expensive film on another camera and develop it to see if that works.</p>

[Alan Marcus]

<p > </p>

<p >I read your description of the problem carefully:</p>

<p > </p>

<p >1. You noticed a problem before developing the film. The film lacked the accustomed springiness. It did not display a tendency to rewind into a roll.<br /><br />I do not think this is relevant. The natural tendency for films to rewind is a variable based on the constituents of the base and moisture content. We are talking about cellulous acetate vs. Mylar and the gelatin contained in the emulsion and the over-coat and the flipside balance coat.<br /><br /><br>

You describe the processed film as being thick at the beginning and having normal thickness at the end. You couldn’t read the edge printing till well near the end of the roll.<br /><br />My diagnosis: Your observation is consistent with film that has been light fogged. While might be possible that the damage is due to X-ray or out-gassing. Out-gassing is exposure to fumes like moth balls, glues, and solvents. Film left in the glove compartment will suffer heat damage plus out-gassing damage. <br /><br />The damage you describe is seen on the front segments. The rear of the roll has little or no damage. 35mm film lacks the black opaque paper backing used in most all other sizes of roll film. This renders 35mm more susceptible to fogging. As a countermeasure the base of the 35mm film is made to be less transparent. Kodachrome and Cine films have a deep black backing that will be removed during process. 35mm black & white stock is deliberately gray. All 35mm films additionally have an antihalation coat that is darker than larger roll sizes. The idea is to prevent light piping and to protect against accidental light fogging. In the event of accidental exposure to fogging light, the outer winds receive more harmful exposure, the inter winds are somewhat protected by the opacity of the protective measures previously described. The edge printing is a photographically applied. If fogged, the edge printing is ruined.<br /><br />Likely the front end is ruined beyond repair. </p>

[toni_nikkanen]

<p>Alan, thanks, I'm sure the problem is that something ruined the film - it remains a mystery just exactly what. The strange thing is that the fogged part is very uniform all the way until it ends, and it ends very quickly at that point.</p>

<p>Anyway I also have now developed more film with the same chemicals and it came out really good.</p>

[wentbackward]

<p>Could be fixer polluted your developer. A very small drop of backwards contamination will ruin the developer.</p>