…Also known as “My Archimedes Moment“.
I wasn’t in my bathtub when it happened (I mean, who has time these days??)
But I may as well have been, ‘cuz that’s about what it boils down to.
So without further ado (as long promised…)
How I fixed my color development.
The issue at hand is a frustrating one: A tendency toward magenta casts in the shadows of self-developed Portra and Ektar.
I apologize in advance if some of these concepts seem overly elementary to you (there is actually nothing ground-breaking here…)
I am embarrassed to say that the solution is a little bit simple.
Given the effort I was undertaking, I am surprised I had not taken this step sooner.
Before I tell you the “how…” I feel I must tell you the “why…”
The first thing that needs to be understood, is that color film is basically arranged in four (relevant) layers. (There are more, but for our purposes today, just the ‘color’ ones matter).
Although these layers are simultaneously exposed (it’s a “speed of light” thing…) they actually develop at differential rates. That is: the film actually has depth.
The second thing is, we may in fact be talking about two separate issues. Namely:
- If your developed photographs have a diffuse color cast (too magenta, or too green) then your starting temperature is off. Your chemicals are either too hot (magenta) or too cold (green).
- If only certain areas are off (the shadows, for example…) then your temperature regulation is flawed.
Let me state it another way: There are two separate details that must be attended to for successful and satisfactory home developing: Precise temperatures, and temperature precision. These concepts sound similar, but they are actually quite different (…yet, uh, interrelated).
(There is a fair amount of misinformation circulating on the intarwebs, mainly because of the confusion regarding the above issues).
The first important point that I will make is this: The manufacturer of your chemicals has specified a certain development temperature and time. The fact is, you can actually use whatever temperature you want–you just have to vary the development time appropriately (just like B&W film!) The problem is, it is rather difficult to know in advance how to vary the time appropriately. (There is actually an equation for it based on the natural logarithm, but I am not going to get into that here). Fact is, many labs do it for a variety of reasons…
Your kit is designed to be used for 3:30 at 102ºF.
Plain and simple.
Therefore, you need to be as close to this starting temperature as possible, to avoid diffuse color casts.
Now for my magentas…
Problems with magenta casts in the shadows are due to differential over (or under-) development of the various layers of the film itself. This occurs for two reasons:
- Despite similar chemical composition, the layers themselves are actually differentially sensitive to the development process itself. They are arranged in a certain manner because of how they filter light. They do not develop in a similar manner.
- Given the “thickness” that I spoke about earlier, the layers themselves have different permeabilities and propensities to develop faster or slower, especially if the temperature changes over time!!
Put another way: Have you ever tried to print black on a three-color printer? (Cyan, Yellow, Magenta…)
It doesn’t look black.
Or rather: it won’t look close to black unless the relative ratios of each color are close to perfect.
So (if you aren’t bored and snoring already…) the short answer to my problem was this:
- Too much magenta in the shadows, means you have too much green in your negatives, which means that this layer was overdeveloped relative to the other two.
- The issue at hand was one of imprecise temperature regulation.
I had always assumed that because I was using an immersion circulator (with a precise starting temperature…) and because the development time was so short (only 3:30!!) that my temperature would be rock-solid stable…
Well my friends, I am here today to tell you exactly what happens when you ASSuME…
The problem is, I wasn’t actually keeping my tank in the bath the whole time…just the chemicals between steps!!
Fact is, from start to finish, the temperature of my developer had dropped by almost 2.5ºC over 3:30! (If “pushing” film, it was even more…)
This is completely unacceptable.
Based on the Kodak spec sheets, the temperature of the process is not designed to vary more than 1 degree Celcius total–this means 0.5ºC up or down!
So how did I solve my problem?
(Well, it’s not totally perfectly solved…see below).
Nothing comes out of the circulator for more than a few seconds of pouring. Then the tank itself goes right back in. This is why the closed systems like the Jobo work so well…the temperature of the whole apparatus is tightly controlled right from start to finish. It is not an insurmountable problem…it just requires close attention to detail.
Now here are the important caveats I have collected over time:
- Certain films are more sensitive to this problem than others, because of the manner in which their emulsions are formulated. Portra (and to a lesser extent, Ektar…) are especially bad because of their focus on preserving pinks and purples in skin tones, and maintaining vibrant colors. The Superia line is relatively insensitive.
- Exposure matters. This may appear self-evident, but again: certain films are more predisposed than others. The whole reason guys like Jose Villa have been so successful (well…that, and his obvious talent…) is that Portra doesn’t actually blow-out as you over-expose it; it just tends towards the pastels. You don’t want to be too far to the right, as you will tend to find these colors. On the other hand, underexposure means having to push the negatives in post, yielding similar issues in the shadows.
- You will still have to do some color correction. Automated processes like the Pakon are designed to take the guesswork out of this for you, by detecting shadow casts; but programs like SilverFast will also do the job. The aim is not a neutral negative, but rather a solid negative without localized issues.
- Old (or overused) chemicals will also cause similar variability. As a result, you may find yourself changing them over before completely spent.
- pH Matters. I’m not going to get into this at length right now, but suffice it to say that if your water supply has issues (Well water, or something…) you may want to consider actually mixing your chemicals up with distilled water.
- Pay attention to how your chemicals are mixed–some of them are hydrates (especially the Blix) and thus incompletely soluble. It is not “Add to 1L of water…” it is actually “Mix up in 500, then top up to 1L. Not a big deal at first, but makes a difference as your chemicals become exhausted.
Seriously though…I think that’s about it for now.
Hope this helps.
(…and don’t get discouraged. You can do this!!)
All the best,
(Oh yeah: The photos! They were shot on Portra 400 (pushed to 800) on the Mamiya, and developed for 4:45–A veritable torture-test for this sort of problem. Check out those blacks!)