Reversal film - re-exposure question

[James1]

HI folks,

I have been trying my hand with expired Agfacolor-syle reversal films, with good results (for expired film) so far

Qustion I have is regarding the re-exposure step - how long, and how intense should the light be?

The Orwo 9165 process states 2mins with a 500W bulb at 75cm, or bright daylight.

I used about 150Wish, quite 25cm-ish away, for about 8 mins. The positive images look good, although the space between frames, and the leader is still quite see-through. The re-exposure was uniform luckily.

Is this sufficient? Does the light have to be very intense? Can the second exposure be overdone?

Grateful for any pointers!

 

[Athiril]

Your exposure is likely more than sufficient, if your film base is too light, I'm probably guessing it's age related fogging of the film, adding a small amount of benzotriazole to first developer may help that somewhat. But you'd have to experiment.

 

[Europan]

Bright daylight is not recommended because you can risk to solarize the remaining silver halide. A frosted 60-W bulb at two feet for 30 to 60 seconds will suffice.

Clamp the bulb to a container from a white plastic and keep the film under water. Move the film, flip the spiral reel over. Second exposure cannot be overdone except for what I write above.

 

[James1]

Thanks Athiril, Europan!

There was definitely some fog on the film, which was a Svema reversal film that expired at the end of the 80s. I think next time I will cut the re-exposure time, but glad to know that it's relatively time-insensitive!

 

[polyglot]

Re-exposure is to completion, so you can't really go too long. In the worst case you're maybe wasting a couple minutes.