Tijmendal
Young photog
Hi all,
I recently started developing color at home. I heard about how much harder it supposedly was than B/W and was a little anxious to start that whole chapter. My first roll turned out fine, which made me sigh in relief; too bad I've had very mixed results since then. This might have had something to do with the different kinds of shoddy films used, but still.
Anyway, I'd like to get a better understanding of the C41 chemical process. I'm using the C41 digibase kit (5 liter, from Maco); this kit doesn't have blix, but seperate bleach and fix. The technical data sheet can be found here.
My last couple rolls turned out a little milky/brown and upon reading the sheet it looks like my bleach/fix is starting to lose its strengt. Fair enough (even though they were supposed to last a couple rolls more). It might be worth adding that they only look milky/brown when looking from the emulsion side. When I look through the base of the film, they just seem a little dark.
After troubleshooting I went back and re-bleached and re-fixed a couple of rolls to see what this would do. It didn't seem to help much. Would this even ever do anything after stabilizing? (so bleach->fix->stabalize->bleach->fix->stabalize is what I did). I've also heard of people using a B/W stop-bath in between developing and bleaching.
This also made me think of cross-contamination and it made me realize I don't know much about what every chemical component does in the C41 process.
Develop: this is pretty self explanatory I think.
Bleach: No clue
Fix: the same as with B/W?
Stabalize: Stabalizing of the colors and wetting agent (is what I read in another thread).
What can spoil what and how fast?
Lastly, and for me most importantly, is getting a better understanding of how strict the times used in the technical sheet are. The developing part is of course very time-dependent (just like with B/W) and the times used here are very important. But what about bleaching, fixing and stabalizing? With B/W I tend to use a stop-bath from 1-5 minutes and I'll fix anywhere from 4-10 minutes; mostly because I'm always running around doing other things in the meantime. I've never had any problems with this because 'over-stopbathing' and 'overfixing' don't happen, unless you're really pushing it.
What about overbleaching, overfixing and overstabalizing with C41 chems? Is that even a thing. I don't like being anal about every little step and rather take it easy. I accidentaly bleached my film for 6 mins instead of 4 and it didn't really seem to matter in the results.
Any answer is appreciated. Thanks!
I recently started developing color at home. I heard about how much harder it supposedly was than B/W and was a little anxious to start that whole chapter. My first roll turned out fine, which made me sigh in relief; too bad I've had very mixed results since then. This might have had something to do with the different kinds of shoddy films used, but still.
Anyway, I'd like to get a better understanding of the C41 chemical process. I'm using the C41 digibase kit (5 liter, from Maco); this kit doesn't have blix, but seperate bleach and fix. The technical data sheet can be found here.
My last couple rolls turned out a little milky/brown and upon reading the sheet it looks like my bleach/fix is starting to lose its strengt. Fair enough (even though they were supposed to last a couple rolls more). It might be worth adding that they only look milky/brown when looking from the emulsion side. When I look through the base of the film, they just seem a little dark.
After troubleshooting I went back and re-bleached and re-fixed a couple of rolls to see what this would do. It didn't seem to help much. Would this even ever do anything after stabilizing? (so bleach->fix->stabalize->bleach->fix->stabalize is what I did). I've also heard of people using a B/W stop-bath in between developing and bleaching.
This also made me think of cross-contamination and it made me realize I don't know much about what every chemical component does in the C41 process.
Develop: this is pretty self explanatory I think.
Bleach: No clue
Fix: the same as with B/W?
Stabalize: Stabalizing of the colors and wetting agent (is what I read in another thread).
What can spoil what and how fast?
Lastly, and for me most importantly, is getting a better understanding of how strict the times used in the technical sheet are. The developing part is of course very time-dependent (just like with B/W) and the times used here are very important. But what about bleaching, fixing and stabalizing? With B/W I tend to use a stop-bath from 1-5 minutes and I'll fix anywhere from 4-10 minutes; mostly because I'm always running around doing other things in the meantime. I've never had any problems with this because 'over-stopbathing' and 'overfixing' don't happen, unless you're really pushing it.
What about overbleaching, overfixing and overstabalizing with C41 chems? Is that even a thing. I don't like being anal about every little step and rather take it easy. I accidentaly bleached my film for 6 mins instead of 4 and it didn't really seem to matter in the results.
Any answer is appreciated. Thanks!
Fotohuis
Well-known
To prevent cross contamination you have to flush with water between each steps and preferably use an Acetic Acid stop of 2%-3% between the C-41 developer and the Bleach.
If you're using it all as one shot it doesn't matter for the rest.
The Bleach and Fixer times are minimum times. If you have a temperature drop you have to prolong them. Only very long times can damage your film.
When re-generating the chemicals you have to omit the Starter because this minilab kit from Fuji Hunt, has been adapted for small tank development by adding a Starter in the first set up which is a chemical rippening of the C-41 developer.
When using a Jobo CPE/CPA/CPP you have to measure the temperature near the first bottle and set it to 38,5C there (strongly adviced by Jobo engineers, not my story) . A CPE is already not so suitable because it does not have a re-circulation pump. The best way for these C-41 (and E-6) home development is a CPA/CPP with elevator or an ATL autolab system.
For example you are using then a 2523 tank for two 135-36 or 120 roll films and use 300ml of chemicals (270ml is the absolute minimum) for each film development in rotary. After 6 films you are re-generating with 100ml fresh chemicals and valid every time for two new films. As already told omit then the Starter.
For the rest it is an easy kit. The life span is about 9-10 months when Part C of the C-41 developer, containing the para- Phenylene Diamine goes to Purple and that's the end!
The critical step is the C-41 developing time of 3:15 Minutes at 100F/37,8C +/- 0,5C. Hence the elevator on the Jobo processor.
If you're using it all as one shot it doesn't matter for the rest.
The Bleach and Fixer times are minimum times. If you have a temperature drop you have to prolong them. Only very long times can damage your film.
When re-generating the chemicals you have to omit the Starter because this minilab kit from Fuji Hunt, has been adapted for small tank development by adding a Starter in the first set up which is a chemical rippening of the C-41 developer.
When using a Jobo CPE/CPA/CPP you have to measure the temperature near the first bottle and set it to 38,5C there (strongly adviced by Jobo engineers, not my story) . A CPE is already not so suitable because it does not have a re-circulation pump. The best way for these C-41 (and E-6) home development is a CPA/CPP with elevator or an ATL autolab system.
For example you are using then a 2523 tank for two 135-36 or 120 roll films and use 300ml of chemicals (270ml is the absolute minimum) for each film development in rotary. After 6 films you are re-generating with 100ml fresh chemicals and valid every time for two new films. As already told omit then the Starter.
For the rest it is an easy kit. The life span is about 9-10 months when Part C of the C-41 developer, containing the para- Phenylene Diamine goes to Purple and that's the end!
The critical step is the C-41 developing time of 3:15 Minutes at 100F/37,8C +/- 0,5C. Hence the elevator on the Jobo processor.
valdas
Veteran
Maco gives too short times for Bleach and Fix. Start at 6min 30sec and then add with each film.
I found this quite useful for developing tips:
http://www.kodak.com/global/plugins/acrobat/en/service/chemicals/cis211.pdf
I found this quite useful for developing tips:
http://www.kodak.com/global/plugins/acrobat/en/service/chemicals/cis211.pdf
Ronald M
Veteran
Chems need to be fresh and have short shelf life after mixing. If you start removing liquids from a 5 liter bottle, air will spoil the remainder.
You need an accurate thermometer and something to check it against.
Temp soak the loaded tank and reel for 10 minutes to get it all up to temp. Cool tanks and reels will lower the developer temp which is critical.
Cross contamination is getting step 2 onto strp one or 3 into 2 or 1. Best practice is to have separate everything.
No hard, you just need to follow the rules.
You need an accurate thermometer and something to check it against.
Temp soak the loaded tank and reel for 10 minutes to get it all up to temp. Cool tanks and reels will lower the developer temp which is critical.
Cross contamination is getting step 2 onto strp one or 3 into 2 or 1. Best practice is to have separate everything.
No hard, you just need to follow the rules.
Fotohuis
Well-known
Well, a CPA-2 needs 1 1/2 hour to warm the 18-20 liter water up to 100/38C. During the last 5-10 minutes you can connect the film drum and I always pre-soak for 2 minutes. An acurate calibrated thermometer is necessary for color film development.