Matt,

I'll try to explain. There are a couple of things here that are dynamic. The paper and paper developer combination has a certain range. It is s-shaped just like the negative tone curve, so it isn't linear. You want your negative to match that curve as closely as possible, except it will be mirrored, because we are working with negative materials.

Now, over-exposure raises the tones you record higher up on the film tone curve, but it does not change the shape of it.

Longer development stretches the shadows and highlights farther apart, increasing total contrast of the negative.
If you develop too long, the highlights will block up, meaning there is no tone shifts in the highest highlights where there ought to be tone shifts.
Note that blocking the negative up is NOT the same as having tones in the negative that fall outside the natural range of the paper, and this is the key to everything.

A shoulder in the negative tone curve simply means that your shadows and mid-tones are developed normally, but the highlights have been 'shrunk' or 'contracted' so that all of the tones fit in a shorter span of range. Because your shadows and midtones are virtually 'normal' you are challenged with addressing only the highlights in the print, and that is, in my experience, difficult.

Now, there is a shoulder in all films. At some point it shoulders off. It's a characteristic of the emulsion. How the film is developed (agitation and time) will affect the shape of the shoulder and where it is located. When you photograph something with higher contrast, the general advice is to expose more (to record the shadows) and then to develop less. That's all fine and dandy, but you may end up compromising the tone curve.

THe gist of it is that: Films have the capacity to record very long brightness ranges. Much longer than the paper. That's why paper negatives have such high contrast. If there is detail in the negative, i.e. 'not blocked up' - it can generally be put down on paper. It may require masking, preflashing, split grade printing, etc, and it may be a pain in the neck to do, but usually it can be done.

So when I say that my 'normal' negatives are calibrated in exposure and development to print well on Grade 2.5 filter in the enlarger, with my paper and my paper developer, it means I have a lot of wiggle room. When contrast is higher it's usually fine to develop normal, because it will still fit on the paper at maybe Grade 1.5 instead. And in the rare case that highlight negative density is so high that I can't make it work at Grade 1.5, it's easy enough to just burn it in. And the key here is that when it gets burned in, it has normal contrast. No trickery needed, just one simple operation.

Fit film curve to paper curve and you have lots of wiggle room. Get a step wedge and make contact prints of negs and the step wedge side by side to see how you're doing with film development. Adjust as necessary. If you can control that part of the process and make great negatives, compensating development will never be necessary.



Quote Originally Posted by MatthewDunn View Post
So again, apologies for what might seem like basic questions, but I am trying my best to learn and this has been a great resource so far. I think I might be confusing tonal compression, exposure density, and what actually happens on the shoulder of an emulsion. In the limited amount of printing I have done thus far, it's been easiest when there is clear tonal separation in the highlights that is present in the negative itself. When that has been the case, I find that a slight increase in the contrast filter (if even necessary) gets me the print that I am looking for without having to dodge and burn (as a general rule - again, the new kid on the block and just starting out). Based on what I have read and what I understand, which is what I am trying to confirm, this means that the range of exposure/development on the film falls more or less on the straight line of the curve. My understanding is that, had there been overexposure, the upper zones or highlights would have been pushed on to the shoulder, resulting in little to no separation in the various tones of things like clouds.

Am I generally on the right path here?

So, my question is then about the comment that compensating developers essentially force the film to shoulder off sooner and why that would be desirable? Again, based on my understanding at this point, that is likely to make life more difficult as you are likely to lose tonal separation in the highlights of the negative itself, making the printing process more difficult.

Guys, I really want to stress a couple of things: first, I can't tell you how much I appreciate all the help I get on these forums. Compared to certain other sites where the tone is much less friendly (no need to name some of the usual suspects), this just seems like a chat in a bar over a beer with a couple of buds; second, part of my confusion seems to stem from the fact that there is a ton of contradictory information on the internet and the information can be a little difficult to piece together from different sites, books, etc.

Thanks in advance for all your help.

-Matt