Unicolor C-41 kit instruction puzzlements & questions

The first head scratcher is why sub-102 degree temperature development times are listed only for the Unicolor drum processor, not small tank or the Jobo. Is there a logical reason that small tank can't be used at lower temps other than the boredom of agitation intervals for a longer period? I know nothing about drum processors, why would there be suggested differences between Unicolor and Jobo?

While there is a nice narrative on getting more use out of the developer, there are absolutely no guidelines such as increased development of 30 seconds for every two rolls or something. Not even for the initial suggested 8 rolls per liter. Just run all 8 rolls at the same time? Doesn't compute for me.

Since this is allegedly the same as Jobo, Beseler, and Tetenal kits, I've tried to find those instructions online but to no avail.

Your thoughts, experiences, and perhaps brand instructions, please!

Oh, yeah, and.....

No suggestions for push processing.

Usually small tank can be temperature maintained in a water bath. Jobo machines also keep the drum half submerged in a tempering water bath. Unicolur drums sit on a roller base, or are rolled on a counter, so they cool as the processing proceeds. You measure with a water run to see how much the stuff cools between start and end temp and then use the average as the temp it runs at for a given ambient temp.

Lower temp is not such a great idea; you want all the different exposed colour layers to do thier development thing at the specified temperature. With off specification temperature there is not as good a chance that all will happen correctly.

Usually for best result you save up and run full tanks. For me that is 4 rolls per litre at 3;15 at 38C, and then if right after the first run, I will run the next 4 rolls at the same time, or perhaps 3:30.

I'm using the Tetenal Press Kit. The little sheet does mention push processing. It is normally 3:30 dev at 39C but a 1 stop push is 4:40 and a 2 stop push is 5:50.

I have a 1L kit and I'm doing replenishment, i.e. I dump it all back in the 1L bottle after I'm done each session.

So far I've run almost all of it at about the same time, 3:30. For one batch I couldn't get the temp above 37C, both my kids had baths and the water heater was rejuving and I didn't feel like going up to the kitchen or getting out a hot plate to boil a pot so I looked at the drum times and guesstimated that 4:40 would work since the time given for 35C was the same as a 2 stop push so halfway from 35 to 39 made me think of the 1 stop push time at 39C. It came out fine.

I always blix for 6:30, again adding a little bit of time if the bath is getting cold.

I haven't added time for any rolls. So far I've put 2 Fuji Superia 800 135-24, 1 Fuji NPH400 120 and 4 Kodak Portra 400VC 120 rolls through it. The kit says normally you get 8 120 rolls or 12 135-24 rolls so I've got a 120 roll and a 126-24 roll to go before I hit the advertised capacity.

The sheet says you can exceed the number of expected rolls by 25%, 50% or 100% depending on your quality standards. So far I'm using fast film and there is visible grain but it doesn't seem to be getting any worse. The color doesn't seem to have shifted yet. Once I go above the capacity of the 1L kit I am going to do them one roll at a time in case it does go bad on me. I'd hate to ruin 2-4 rolls at once.

As soon as it goes bad I have another 1L kit to open though I am, again, going to wait until I have at least 8 rolls or so ready to go. I wish the stuff lasted as well as B&W chems so I could develop a roll or two any night.

Thirft store microwave ovens should be your friend. Mine is next door in the laundry on a shelf above the dryer.

Actually it used to be in the kitchen. It 'died' and my wife rushed out to replace it before I could look at it. Ireplaced a $2 fuse, and it has been 'mine' for a few years now. It is great for warming stored solutions quickly. My basement darkroom can go to 15C in the winter, if closed up for a day or more.

I use a water bath that is a small cooler that has a glass tube fish tank heater and water recirc pump from the 'pet superstore'. The mechanical bimetalic heat control has the stop tabs busted off to wind it up to 38C.

I'd need a microwave that doesn't go "BEEP BEEP BEEP" at the end as I often do my processing in early morning or the wee hours. I'd need a restaurant model I guess or one I could tinker with.

hpulley said:

I'd need a microwave that doesn't go "BEEP BEEP BEEP" at the end as I often do my processing in early morning or the wee hours. I'd need a restaurant model I guess or one I could tinker with.

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Some just go "Bing!" once. I wouldn't own one that beeped at me, thank you very much!

Paul Verizzo said:

Some just go "Bing!" once. I wouldn't own one that beeped at me, thank you very much!

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Yeah, the old ones with a mechanical dial, I remember those. Still don't want to wake anyone and especially not the dog...

hpulley said:

Yeah, the old ones with a mechanical dial, I remember those. Still don't want to wake anyone and especially not the dog...

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Not to get sidetracked, but the one in my kitchen is digital and it only dings once.

I really prefer the old fashioned dials, the last unit I bought that was my decision maker. Much faster to use, close enough.

hpulley said:

I'm using the Tetenal Press Kit. The little sheet does mention push processing. It is normally 3:30 dev at 39C but a 1 stop push is 4:40 and a 2 stop push is 5:50.

Isn't that a lot of extra time? I though one stop was typically 30 seconds. No?

I have a 1L kit and I'm doing replenishment, i.e. I dump it all back in the 1L bottle after I'm done each session.

Not to pick nits, but to pick nits, that's "non-replenished." Replenishment requires adding unused developer.


I haven't added time for any rolls. So far I've put 2 Fuji Superia 800 135-24, 1 Fuji NPH400 120 and 4 Kodak Portra 400VC 120 rolls through it. The kit says normally you get 8 120 rolls or 12 135-24 rolls so I've got a 120 roll and a 126-24 roll to go before I hit the advertised capacity.

As the Unicolor narrative on getting more capacity says, there are so many unknowns, so the suggestions are conservative. I'm just surprised that there are no adjustments after two rolls or something. I know I've seen small tank instructions somewhere along the line and it was the order of adding 15 seconds for every two 36 exp. rolls. I mean, if you get good results after the suggested 8 rolls w/o adding time, there's obviously a LOT of capacity left.

Once I go above the capacity of the 1L kit I am going to do them one roll at a time in case it does go bad on me. I'd hate to ruin 2-4 rolls at once.

And start adding time?

As soon as it goes bad I have another 1L kit to open though I am, again, going to wait until I have at least 8 rolls or so ready to go. I wish the stuff lasted as well as B&W chems so I could develop a roll or two any night.

I think it lasts longer than you think! In this thread, the guy uses developers over a year old with "decent" results. Dead Link Removed The one old batch that didn't work, IIRC, had air in the bottle instead of either exclusion or inert gas. And this Shutterbug writer has been freezing his developer for years, as I've experimented with with B&W. Everyone shudders, but why not? http://shutterbug.com/columns/the_darkroom/0199sb_inthedark/ What I'll be trying is if I have a day or so between rolls, I'll refrigerate in an accordian bottle with all air excluded. If more than a couple of days, into the freezer it shall go. I've also made some leader snips tests developed in daylight that I can use as a reference......I hope.

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Mi dos centavos!

Paul Verizzo said:

Mi dos centavos!

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For the push processing times I'm just quoting the instructions, 4:40 for one stop, 5:50 for two. Seems like a lot of extra time but what do I know?

Sorry, replenishment, non-replenishment, I was confused. I was just saying that I wasn't using the developer one shot. I'm using non-replenished but without time adjustments. The sheet just says to check the quality, etc. it doesn't really tell you to start adding time. With B&W when I'm working from 1L of developer for 10 rolls I start adding time on the second roll and by the 10th the time is double but it seems the color stuff doesn't need that. Again, I don't know why.

I might try starting to add some time after I reach capacity. I don't have a densinomiter however so I'm not sure how to really check if I'm overdoing it or doing it just right. At the moment I just eyeball it and check to see the density of shadows and highlights, see if I'm still getting detail, not too much grain, no color shift.

I certainly won't throw my chems out until they start to go off. I am refrigerating mine when not in use though that makes it take even longer to warm up for the first roll...

hpulley said:

For the push processing times I'm just quoting the instructions, 4:40 for one stop, 5:50 for two. Seems like a lot of extra time but what do I know? Ah, I see that now on the Arista instructions, there are no suggestions on the Unicolor. IIRC it's Kodak that suggests 30 seconds for a one stop push. I guess only an experiment will tell!

I might try starting to add some time after I reach capacity. That sounds logical. I'm still perplexed that with all of the alleged and real precision needed for color processing, there is no increase in time suggested.

I certainly won't throw my chems out until they start to go off. I am refrigerating mine when not in use though that makes it take even longer to warm up for the first roll...

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Don't forget, freezing is an option, too! As to warmup, that's what a microwave or just old fashioned time is for. Better that than tossed chemicals.

Mi tres centavos.

hpulley said:

I'm using the Tetenal Press Kit. The little sheet does mention push processing. It is normally 3:30 dev at 39C but a 1 stop push is 4:40 and a 2 stop push is 5:50.

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I checked the Kodak sheet on Flexicolor in small tanks, and it offers push processing times for 800 speed Portra only. Indeed, only 30 seconds for a one stop, 60 seconds for a two stop push.

While I understand different brands will have slight variations in suggested time and temp, these suggestions are anything BUT slight. Maybe the answer is "Try it and see what happens."

Paul Verizzo said:

I checked the Kodak sheet on Flexicolor in small tanks, and it offers push processing times for 800 speed Portra only. Indeed, only 30 seconds for a one stop, 60 seconds for a two stop push.

While I understand different brands will have slight variations in suggested time and temp, these suggestions are anything BUT slight. Maybe the answer is "Try it and see what happens."

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I don't know but you can click on the links someone already scanned from the Tetenal sheet here:
(there was a url link here which no longer exists)

2 stops under 4x normal ISO speed increase time 1.5x (i.e. 3.5min x 1.5 = 5.25min)
1 stop under 2x normal ISO speed increase time 1.25x (i.e. 3.5 min * 1.25 = 4.4min)

Oops, so I was actually not quite right. It is a decimal, not seconds so 2 stops is 5:15 and 1 stop is 4:24. Sorry about that... Both of those assume 39C, I dev'd at 37C for 4:40 and it came out fine so it may not be as critical as they say (which you said too).

And checking again it says even after a week it may not work so I wish I'd had time to soup my Solaris 200 last night... must soup it tonight! That is the last C41 roll I have finished though I have a pro pack of expired Portra 160NC 120 that I just opened and loaded a roll in a film holder so I was hoping to get through that as well so I really do hope the sheet is wrong about it going so dramatically downhill after just a week in working solutions.

hpulley said:

I don't know but you can click on the links someone already scanned from the Tetenal sheet here:
(there was a url link here which no longer exists) Exactly like the Arista kit! LOL!

2 stops under 4x normal ISO speed increase time 1.5x (i.e. 3.5min x 1.5 = 5.25min)
1 stop under 2x normal ISO speed increase time 1.25x (i.e. 3.5 min * 1.25 = 4.4min)

Oops, so I was actually not quite right. It is a decimal, not seconds so 2 stops is 5:15 and 1 stop is 4:24. Sorry about that... Both of those assume 39C, I dev'd at 37C for 4:40 and it came out fine so it may not be as critical as they say (which you said too). Now, I've never made a math misteak...... <roll eyes>

And checking again it says even after a week it may not work so I wish I'd had time to soup my Solaris 200 last night... must soup it tonight! That is the last C41 roll I have finished though I have a pro pack of expired Portra 160NC 120 that I just opened and loaded a roll in a film holder so I was hoping to get through that as well so I really do hope the sheet is wrong about it going so dramatically downhill after just a week in working solutions. Did you check out the link about the guy using year old developer? I think the shelf life is greatly under rated. Keep it cold, keep the air out, keep on using!

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Thanks for your replies.