Two Questions Regarding E6 Techniques and Equipment

[NortheastPhotographic]

I'm leaving NYC soon for Portland Maine, so my lab access is going to become more limited soon. I want to get back into developing my own color film (which I used to do in College) and I've gravitated toward chromes in the recent months... I'd like to start developing my own E6 at home in steel tanks using the available chemistry kits.

So, any advice on an affordable tempering bath solution that is reliable and accurate? I've seen one DIY solution that involved an aquarium heater, but I can't see how that would be very controllable or accurate. Is there a use laboratory machine I could scour ebay for?

Secondly, I've seen some low-temperature instructions out there, with extremely extended times. I think 26 minutes at about 80 degrees. Has anyone experimented with low temp E6 development?

Thanks folks!

 

[dE fENDER]

Secondly, I've seen some low-temperature instructions out there, with extremely extended times. I think 26 minutes at about 80 degrees. Has anyone experimented with low temp E6 development?

Using low temperature with standard e6 kit will give incorrect curves at any temperature, except 100F. To correct this you have to do chemical color correction, which is quite hard, so I'd like to hear the recipes of such successful experiments too (from people who own a densitometer) ...

If you are planning to use your slides only for scanning then, as well as in the C-41 case there is no such problem, cause you can correct curves as postprocessing.

 

[adelorenzo]

You may be able to find a Jobo for a reasonable price. A basic CPE2 or CPE2+ setup (without lift) can be had for a few hundred dollars based on recent sales here. I didn't pay much for mine and I've been getting good results using E-6 tetenal kits.

 

[701der]

You may be able to find a "water bath" on eBay. They are used to keep chemicals at a constant temperature. I got mine for $5 plus about $20 for shipping. It maintains a constant temperature within a degree or two F. I keep the e6 chemical bottles in it while processing, and I float my jobo tank in it while I hand rotate it. Works very well for not a lot of money.

 

[MattKing]

The Sous Vide cooking solutions are used by some: Dead Link Removed

 

[NortheastPhotographic]

Using low temperature with standard e6 kit will give incorrect curves at any temperature, except 100F. To correct this you have to do chemical color correction, which is quite hard, so I'd like to hear the recipes of such successful experiments too (from people who own a densitometer) ...

If you are planning to use your slides only for scanning then, as well as in the C-41 case there is no such problem, cause you can correct curves as postprocessing.

http://www.freestylephoto.biz/static/pdf/product_pdfs/arista/AristaE6.pdf

I got the recipe from the 2nd page of the Arista E6 kit. I figured, why include it at all if it doesn't work... Nobody has tried this?

 

[Rudeofus]

These professional setups cost an arm and a leg, so make 100% sure it's worth the effort with the volume you plan on processing. I preheat my E6 chems in a bucket filled with hot water, and as soon as the thermometer reads 38°C/100°F, I use them. Between FD and CD there is a wash step, which can be extended as long as it takes to get the CD to the correct temperature.

My basic procedure is get liquid to a few degrees above 38°C/100°F, fetch bottle out of water bucket, with thermometer in bottle wait until correct temperature is reached, then use immediately. Bathes after CD are not that temperature critical, so I use them at whatever temperature they have after sitting in the same water bucket.

 

[dE fENDER]

http://www.freestylephoto.biz/static/pdf/product_pdfs/arista/AristaE6.pdf

I got the recipe from the 2nd page of the Arista E6 kit. I figured, why include it at all if it doesn't work... Nobody has tried this?

The note here: At 70F temperature will show density and color shift.

But if you will use test strips with densitometer, you see, that even at 99F (with proportinaly longer processing time) there will be shifts beyond E6 tolerance limits. And again, as I said - if you purpose to scan - such procedure may be suitable. Otherwise, solutions for different temperatures must have different chemical composition.

 

[RPC]

Secondly, I've seen some low-temperature instructions out there, with extremely extended times. I think 26 minutes at about 80 degrees. Has anyone experimented with low temp E6 development?

Considering the extra time you spend processing at low temperature, and the resulting corrections you'd have to make in PS or other software, to me it would be easier just to process at the correct temperature to begin with, and have a proper slide to work with.

 

[Sirius Glass]

You much better off following the directions and processing at the proper temperature.

 

[pbromaghin]

I have a PhotoTherm circulating water bath like this:

http://www.studiolighting.net/items...4-Constant-Temperature-Bath_301857448095.html

and it works great. Lots cheaper than a Jobo.

 

[destroya]

this, a large turkey roaster, is what i have used for many years to do e-6 and c41 films. works great and is cheap. the warm cycle keeps the bath at 102 which keeps the chems at 100. I use old 1.75 liter jack daniels glass bottles to store and warm the chems in.

https://www.walmart.com/ip/Mainstay...er-with-High-Dome-Lid-14-Quart-Black/53986439

if you arent gonna develop the film at 100, like you are supposed to, then i would not waste the film or effort to do it. you will be unhappy with the results. do it at 100 and be happy with what you see

 

[Rudeofus]

The further you get from 100F, the worse the color becomes. I did extensive testing of this with color negative film and posted the results on this site before.

But if you will use test strips with densitometer, you see, that even at 99F (with proportinaly longer processing time) there will be shifts beyond E6 tolerance limits.

I have spent considerable effort in finding a thermometer which would reliably and repeatably measure with 0.1°C accuracy. Note: accuracy, not resolution. Failing this, I looked for electronic parts to do this, after all I am engineer, give me a decent integrated circuit and I'll do the rest. But to no avail, such parts just don't really seem to exist as far as I can tell.

Next question, even if you had that perfectly accurate thermometer: how do you measure and control temperature of your FD/CD, while you process your film? There is a sizable temperature difference between water jacket and inside the film tank, and this temperature difference will strongly depend on ambient temperature and humidity.

I am therefore quite unsure how to treat these "If you're off by 0.5°C you're toast" claims. I guess successful home processing seems to depend in large part on the fact that our eyes are a lot less critical than these test strips.

 

[RPC]

I don't do E-6 but do C-41 and I have run repeated tests to determine just what the developer temperature should be before I begin processing and have measured what it is at the end to average within .5 degrees of 100F (Kodak says .25 but PE has said .5 is more realistic)-- the range of 99.5 to 100.5F. The temperature only has to average within this whole degree range. I would never just measure the water bath. I use a small tank and a large water bath and I don't believe ambient temperature has much of an effect. I measure with a digital thermometer (for quick results) that I have checked against a Kodak process thermometer. I am confident that it all works because I check for crossover with a gray scale and densitometer and get results in line with film manufacturers' literature. Tests show I do get crossover if I let the temperature drift too much. With a slide, one can simply photograph a gray scale and look at it after processing.

So developing at the correct temperature isn't that hard to do, but then again it could be affected by one's processing scheme. Mine works for me, YMMV.

 

[GRHazelton]

Back in the day I processed E-?, beginning with the process using a photoflood bulb for reversal. I don't remember the temperature, but it was the familiar +- .25 degrees tolerance. I used a Kodak process thermometer, and a water bath with water running from a kitchen tap to maintain the temp. A little nerve wracking, but worked fine. I recently scored an immersion heater for about $35.00, but I haven't tried it. It would certainly simplify matters.

 

[pukalo]

I use a Styrofoam cooler fill with water and chemical bottles at 110-115 degrees and let it slowly drift down. When the FD is 100 I start processing with the Paterson tank put in the water bath. The CD stays close enough to 100 during the 6:15 FD time, its still within the tolerances given in the Tetenal instructions. If cold out I sometimes add a small amount of hot water to the water bath during FD so the CD temp stays in spec.also, I spin the stick to agitate much easier and cleaner than investing the tank.
Its EASY, no need to buy expensive equipment. Ive done hundreds of rolls with great results. A Paterson hand tank, a cheap Styrofoam cooler, and a digital cooking thermometer are all you need.

 

[mshchem]

Occasionally these come up on Ebay. I have used these for years, Doran/Dev-Tec Processor Temperature Control Model TC-750 . These are neat little immersion heaters, adjustable, has a sensor that if dry it will shut off. 750 W so they heat up the water faster than a big Jobo. Cost is usually less than $50. Aquarium heaters work too.

Having said that, I have two Jobos that I have picked up cheap, and made minor repairs. Super neat machines. The new machines made by Jobo have MODERN electronics. They cost an arm and a leg. I suspect that these units will be running strong 50 years from now.

I have a microwave in my darkroom, I warm up the chemistry in a beaker to get it close, then put into a bottle and place in my bath. This saves about a hour.

The styrofoam cooler method works great. I did this for my first 10 years. Just keep a pitcher of HOT water to add a little heat if needed. 1st developer is the most critical to have spot on at 100F. Don't waste your time at low temperatures.
Don't hesitate, order a Tetenal kit and do it.
Best Mike

 

[RPC]

You are right, a small out-of-tolerance condition would probably not be noticible. But one should still try to be accurate, to eliminate as many factors as possible that could contribute to poor quality.

 

[Rudeofus]

There is considerable difference between a 1 degree variance and these instructions that claim processing temperatures of 80F or even 68F. While a 1 degree difference may show up with critical densitometric readings or strict control strip use, I doubt anyone would see a real difference in color or density. The really low temperatures given in some instruction sheets do, though. They are a big enough difference that I wonder why they are given at all.

This more or less confirms my thought, that one should stick as close to optimal parameters as feasible, but that the process can easily handle small variations. Note, that I never advocated room temperature processing for E6 or C-41.

The reason why these low temp instructions are given is likely because people are more inclined to buy these kits, if they think that room temperature processing could also work. I talked to a large photo materials dealer about potential needs for innovative products, and he told me plainly "make a single concentrate C-41 CD, because people hate mixing three concentrates into one liquid". He also told me "we tried development of C-41 film with RA-4 kit chems, and for us the results were indistinguishable from lab developed negatives". This shows to the kind of expectations of the amateur home processing market.

 

[Mr Bill]

I have spent considerable effort in finding a thermometer which would reliably and repeatably measure with 0.1°C accuracy.

Hi, I was involved in the same sort of thing early in my photo lab years, when I spent considerable time working in QC. We came to the conclusion that our best course of action was to rely on the Kodak Process Thermometer, the "best" they had to offer (at least to the general public). Kodak "Process Control Strips" would be the final arbiter of "correct" processing. (Since Kodak invented the C-41 process, they are the de facto authority on what "correct" processing is.) These strips are, in reality, the only way an outside processor can determine if they are within spec or not; the normal parameters - time, temperature, and agitation - are not enough for precise control. This is mainly due the difficulty of quantifying "agitation," but the temperature issues are another variable.

Anyway, when we needed to verify a processor temperature, someone would use a Process Thermometer held near that machine's temperature probe to confirm the digital readout, as best we could. After this, that machine's temperature controller would handle things. As a note, we kept three Process Thermometers in our chem lab (with restricted access) - if there was a disagreement, two out of three won the "argument."

I don't really want to advise others on how to proceed, but for a casual user, I'd say to buy the best thermometer that you are willing to pay for, then follow manufacturer instructions. If results are good enough for you, they're good enough. If you want to go a step farther, split a roll with a pro lab and compare their process results with yours (make sure you know how their control plots look, though). If you want to go farther yet, start working with control strips and a densitometer (a friendly lab might sell you some and read them for you).

I should say that I've never processed E-6, mainly color neg and printing. But if you had an "in control" (more properly said "in spec") C-41process as per control strips, then changed the developer temperature by 1/2 degree F, I'd bet a lot of money that your charts would be out of spec.

If we would have had a film processor that went an indicated 3/10 degree F off (on the digital readout), AND WE DIDN'T KNOW WHY (and didn't have assurances that it was coming right back), we would have put on a control strip and "leadered it down", meaning to shut down a production machine running 50 feet of film per minute. It was that serious to us. But we had specific needs with a finely tuned production system; most people would not be so finicky. Btw, it was a chain studio portrait lab, printing probably more paper volume than most people here could imagine.

 

[Mr Bill]

But if you will use test strips with densitometer, you see, that even at 99F (with proportinaly longer processing time) there will be shifts beyond E6 tolerance limits. And again, as I said - if you purpose to scan - such procedure may be suitable.

Yes, I'm pretty sure this right. No first-hand knowledge from me, but I'd bet money on it.

 

[Mr Bill]

I measure with a digital thermometer (for quick results) that I have checked against a Kodak process thermometer. I am confident that it all works because I check for crossover with a gray scale and densitometer and get results in line with film manufacturers' literature.

RPC, this sounds like a good way to go. But just fyi, a set of densitometer readings doesn't guarantee that the paper will see things the same way. I remember once, lots of years ago, doing an extended trial with a n alternate manufacturer's materials. They wanted us to also run their control strips, which plotted very badly. Consequently they came back with a set of corrective "fudge factors" to match our densitometers to their materials. The narrow spectral-range densitometers were apparently reading off to the side of the dye absorbance peaks, so they estimated what the error would be at different densities. I know you have a pretty good handle on what you're doing, so I'm just passing on a little personal experience.

Also, lack of a visual color cross in a gray scale doesn't guaranteed the same in skin tones, and vice versa. We used to test for both whenever were evaluating new papers. We'd also do the same testing under a wide exposure range with a wide range of skin types. Most people don't have to be so finicky, but we were making decisions with respect to a lot of money being spent, and portrait work was our business.

 

[RPC]

RPC, this sounds like a good way to go. But just fyi, a set of densitometer readings doesn't guarantee that the paper will see things the same way. I remember once, lots of years ago, doing an extended trial with a n alternate manufacturer's materials. They wanted us to also run their control strips, which plotted very badly. Consequently they came back with a set of corrective "fudge factors" to match our densitometers to their materials. The narrow spectral-range densitometers were apparently reading off to the side of the dye absorbance peaks, so they estimated what the error would be at different densities. I know you have a pretty good handle on what you're doing, so I'm just passing on a little personal experience.

Also, lack of a visual color cross in a gray scale doesn't guaranteed the same in skin tones, and vice versa. We used to test for both whenever were evaluating new papers. We'd also do the same testing under a wide exposure range with a wide range of skin types. Most people don't have to be so finicky, but we were making decisions with respect to a lot of money being spent, and portrait work was our business.

Interesting story about the densitometer readings. You mentioned reading alternate materials, so the densitometer filters probably weren't suited for reading them as they would be for film?

In my case I used to do HD-LD readings, the kind control strips use, but I switched to actually plotting the curves of the gray scales to see actual curve shape since the HD-LD doesn't really tell you that, and I get a better indication of how parallel the curves are. It may not tell me everything, but it is the best I can do, and has really helped me when fine-tuning my C-41 process and experimenting.

 

[Rudeofus]

Let me sum this up:

1. You start with a process with standard chems and times and temperatures dialed in as accurately as possible
2. You then use process control strips from one specific vendor to fine tune your processing setup, which includes changes to chemical composition of the processing bathes and optional changes in timing and temperature.
3. Process strips from other vendors likely give completely off results.
   
4. Different densitometers give different readings with the same process control strip, too.
5. Typical test strips are not necessarily made by the maker of the process chems, and the densitometer maker is a completely separate company.

The more I think about this, the more I doubt, that such a procedure gives us a process that yields precise results across all film brands. A lot of these "properly dialed in" processes seem to strongly depend on the fact, that our eyes simply won't notice slight color cross over or other flaws.

 

[dE fENDER]

I have spent considerable effort in finding a thermometer which would reliably and repeatably measure with 0.1°C accuracy. Note: accuracy, not resolution. Failing this, I looked for electronic parts to do this, after all I am engineer, give me a decent integrated circuit and I'll do the rest. But to no avail, such parts just don't really seem to exist as far as I can tell.

Next question, even if you had that perfectly accurate thermometer: how do you measure and control temperature of your FD/CD, while you process your film? There is a sizable temperature difference between water jacket and inside the film tank, and this temperature difference will strongly depend on ambient temperature and humidity.

I am therefore quite unsure how to treat these "If you're off by 0.5°C you're toast" claims. I guess successful home processing seems to depend in large part on the fact that our eyes are a lot less critical than these test strips.

Unfortunately, I haven't got a densitometer, but the several people who has one and took some test with strips, told me the next: it's possible to debug your E-6 process using usual analog color thermometer, paterson, for example. But, for my expirience of color RA-4 printing - getting low by 1°C will give a visual color shift. It's just too much. Of course, there are many zones in tank/tray with different temperature, but with some practice, you will know when the temperature at the film/paper is in limit, even your thermometer shows that it's too cold/hot.