The last time I developed an HP5+ (the day before yesterday) I noticed that for the first time the pre-wetting water came out of the tank crystal-clear... where is the dark colour the Ilford films dyed the first bath with? It was fun, seeing all this dark water coming out of the tank, even though the water you poured in was clear... Is it a new emulsion, with a different anti-halo layer ? Am I doing a mistake ?
I have been using FP4+ in 120 and there is quite a dark color to the wash water when I dump it. In 35mm I use HP5 and there is basically no color. In fact, I also get no color from Agfa in 35mm and when I used APX 100 in 120, it was almost black.
I have been using FP4+ in 120 and there is quite a dark color to the wash water when I dump it. In 35mm I use HP5 and there is basically no color. In fact, I also get no color from Agfa in 35mm and when I used APX 100 in 120, it was almost black.
You may be right. I usually develop 120 (or sheet) films, and the colour of the water comes out grey-green. This time it was a student's film (35mm) and that is why there was no colour. So, this means that the Anti-Halo layer in 35mm is different that the one in 120 ?
Yes, there's a difference between 35mm and 120. If the anti-halo layer on a 35mm film were on the back like it is on 120, your camera would quickly be full of gunk as the layer scraped off. The 120 film is protected by the backing paper, so it doesn't rub off. Most 35mm film uses a tinted base material instead.
Yes, there's a difference between 35mm and 120. If the anti-halo layer on a 35mm film were on the back like it is on 120, your camera would quickly be full of gunk as the layer scraped off. The 120 film is protected by the backing paper, so it doesn't rub off. Most 35mm film uses a tinted base material instead.
I've been using hp5+ in 120 and 8x10 formats for many years. The anti halation backing always washes off as a purple black color. However, I have never seen it happen with hp5+ 35mm. I have noticed several difference between the 35mm and the larger roll and sheet formats:
1. the base in the 35mm is darker. This seems to support the notion that it is dyed
2. The development times are different for 35mm. I use PMK or Pyrocat and the 35mm have always required much less development time than the medium and large formats. I shoot all formats at 400 (unless I'm going to use stand development).
Development times for medium format and large format in PMK are 13 minutes. 35mm requires 8-9 minutes. Not sure why this is true, but if I run the 35mm more than 9 minutes, the negs will be overdeveloped and the grain will start to get excessive.