Emulsion soft, wipes off

[ciaran_mcmenemy]

<p>hi! I developed a 120 reversal previously<br /> details: Shanghai GP3 (100 used as 400). I used a temperature of 25'C for 11min initial dev with FD10 1+9. Agitation as normal. Washed, then a H2SO4 and KMnO4 cool purple bleach for 5 min, again at the same temperature. Washed, then cleared with sodium meta. It was a pinky colour prior to this I think, it turned banana yellow afterwards. Washed again - meta smells quite noxious, if that's te word. After redevelopment with a fresh solution of FD10 in the same way as for first development (a bit longer just in case) I hung the film up after more washing. I didn't fix it.<br /> I noticed that the emulsion was very soft and wiped off easily. I poured cold tap water on it but it didn't help it - I had to wait for it to dry. Why?<br /><br />Not just for GP3, I noticed it with another film too - it was 35mm Foma or Pan 400<br /> ----<br /> the film is some 'problem' GP3 from 86daigou, i.e. shipped from China. {I bought a few boxes on eBay I while back, and they proved to be great. Easy to push, although development could get lengthy. } As for this one, development yielded some sort of sticky residue which had to be cleaned (must be the weird backing paper) and I saw frame numbers on the film. The frame numbers are quite interesting in their own right (just not for serious photos) because it makes you, hm, aware that it's a photograph - it's something that happened in real life, but it itself is not quite real.<strong>.</strong> It's the same feel as watching an 8mm film with the sprockets showing, I guess?</p>

[ciaran_mcmenemy]

<p>image</p>

[peterbcarter]

<p>The strong acids make the emulsion soft. Not much you can do but be careful until the emulsion dries again. FYI: It get's worse the higher temp you develop it with.</p>

<p> </p>

[glen_h]

<p>25C is getting on the high end for normal black and white films. </p>

<p>E6 and C41 films have hardened emulsion to survive the higher temperatures.</p>

<p>Some processes have a pre-hardener step to help against over soft emulsion, <br>

but harder emulsion also slows down diffusion of chemicals in and out.</p>

[ciaran_mcmenemy]

<p>Peter, that helps so much. I should have realised that acid would do that!! Thanks for the advice Glen - I'm surprised that 25'C is considered hot since it's quite a routine temperature I use, being only a few degrees higher..</p>

[peterbcarter]

<p>Depending on the thickness of the film (gp3 is thin), you can 1/2 strength the bleach, and leave it soaking a little more. I've been doing that for several years now.</p>

[ciaran_mcmenemy]

<p>great idea, so how long extra would you do it for? I'm guessing you examined the film until it had the right colour. <br>

Is it something to do with the pH?</p>

[ciaran_mcmenemy]

<p>I guess it's a little thin - tell you what, Lucky SHD (100) is <em>incredibly</em> thin. It's like comparing paper to cardboard. Wow.</p>

[peterbcarter]

<p>I've done both and they are equally good for reversals.</p>

<p>I generally bleach for 5 mins. But you can tell by looking at the 35mm leader; it should be completely clear. If you are doing 120, pop the lens off and shoot a frame....it should be completely clear. Not enough and you will see fog. Too much and it starts dissolving your image. It's not super critical, just check to make sure you have enough.</p>

[ciaran_mcmenemy]

<p>hey, thanks for the guidelines; really helpful. I'm doing more reversals today and used a slightly weaker bleach. After clearing I exposed it to light, and I noticed that the emulsion is actually fine. After second development it feels slippery and hey presto it wipes off. I'm suspicious of the developer... hmmm...</p>

[peterbcarter]

<p>It's really not the developer. You will never get this part out of the process completely. You just have to be careful how you handle the film.</p>