Multiple grades in LED-based enlarger

[albada]

I'm wondering whether folks would like this proposed feature in the controller of a LED-based enlarger.

Instead of telling the controller what grade to expose for the main, dodge, or burn exposures, you would tell it the grades you want on the print and not grades used during exposure. For example:

You could tell the controller (via buttons and knobs) that you want the overall print to be grade 2, and a dodged-area to be grade 3. That's grades 2 and 3 on the print.​

During the dodge, it would expose at grade 1. So everything outside the dodged area is grade 1 at this point.​

For the remaining (non-dodged) time, the controller would expose everything at grade 3 (base exposure), making the dodged-area grade 3, and everything else grades 1 and 3, combining to be grade 2, which is what was specified.​

Basically, the controller would calculate and perform split-grade maneuvers behind your back with the LEDs to obtain the print grades you specified.
You would tell the controller the grades you want on the print, and it would figure out how to get them.

Note that you often want to dodge/burn areas to the highest and lowest possible grades, so the controller could let you specify "max" and "min" as the grade, in addition to a number. And also "base" (the default) when you don't want to change grade.

This feature lets you specify grades-on-print and the controller figures out how. Would you find that helpful?

 

[koraks]

Would you find that helpful?

Personally, no. It sounds overly convoluted and unintuitive to me. But that's entirely personal.

 

[pentaxuser]

You could tell the controller (via buttons and knobs) that you want the overall print to be grade 2, and a dodged-area to be grade 3. That's grades 2 and 3 on the print.​

During the dodge, it would expose at grade 1. So everything outside the dodged area is grade 1 at this point.​

For the remaining (non-dodged) time, the controller would expose everything at grade 3 (base exposure), making the dodged-area grade 3, and everything else grades 1 and 3, combining to be grade 2, which is what was specified.​

Basically, the controller would calculate and perform split-grade maneuvers behind your back with the LEDs to obtain the print grades you specified.

It sounds very complicated and a Herculean task for anything except the very best of AI programming but just as a humorous remark which is not meant to denigrate your idea, it struck me that if you say that part of the quote above quickly, it sounds like Lou Costello trying to sum up what Bud Abbott has told him at about the halfway point in the "Hu's on first base" conversation

pentaxuser

 

[cowanw]

Instead of telling the controller what grade to expose for the main, dodge, or burn exposures, you would tell it the grades you want on the print and not grades used during exposure

One prints a negative with a grade of light to result a print. I am stumbling on whether there is such a thing a grade on the appearance of a print.
Perhaps you can define what " a grade on a print" is so that we are all imagining the same thing.
I imagine you refer to a certain range of tones, but the appearance of a print and it's tones (Ansel Adams term) relies on the negative to start with and the negatives are never the same as perfect Stouffer test negatives. Even as one prints a Stouffer test neg with increasing contrast there is mostly a full range of tones; even while more of the image is just black and white.
While we do speak of a grade X negative for example; what we really mean is a negative that requires a grade Y light to print to our preference.

 

[DREW WILEY]

You're making an easy problem complicated. First of all, graded papers are almost extinct; and when there were around, the precise grade spacing differed between different products. Then you'd have to also factor in potentially different developers, development times, on and on. And endless abyss.

There are far less complicated ways to differentially change the contrast on different portions of the negative that don't require any kind of electronics at all.

Just how is this thing supposed to read a "map" of the negative to program the head to do what you want? Are you going to scan a neg and then fill in all that information?

If you just want to be able to control the relative dominance of blue versus green LED's mixed together, that's already been done. You can already buy something like that, for a hefty price at least, or else make it yourself.

But how you specified all this is mystifying. For example, you speak as if Grade 3 is high contrast. It isn't, or wasn't.
Many practitioners of graded paper printing thought of Grade 3 as the midpoint. But grade spacings were never identical anyway.

 

[albada]

These responses show the value of having folks review a UI.
How about having an LED controller offer a "Type" option for a dodge which has three possible settings that avoid the concept of grade:

Normal - Your everyday, rotgut, dodge.​

Green-only - A split-grade dodge that removes only green.​

Blue-only - A split-grade dodge that removes only blue.​

Is that clearer?
BTW, the same "Type" choices would apply to burns.

 

[DREW WILEY]

Yes, that's a better description. But again, that kind of technology already exists.

 

[koraks]

These responses show the value of having folks review a UI.

Sure, but at least what I'm saying here is highly personal, so I'm not sure if it's all that valuable to you, per se. So please bear this in mind in the remarks below.

Normal - Your everyday, rotgut, dodge.Green-only - A split-grade dodge that removes only green.Blue-only - A split-grade dodge that removes only blue.

I see what you mean, but personally, I've never experienced the need for this. My approach to burning & dodging is caveman-simple, and consists of 2.5 rules:
Rule 1: I only burn, don't dodge. Instead of dodging a part of the frame, I usually end up burning much of the remainder. The end result maybe almost the same. The thinking is different, and the practical requirements on a controller are also different.
Rule 2: I virtually always burn at the grade I've made the main exposure on. I burn to get more punch in a certain area and this means I virtually always want to bring out contrast in that area, too. Even (especially) if it's a sky.
Rule 2.5: on the odd occasion I want to burn at something other than the grade I've already set the controller to, it's virtually always the highest grade, and never the lowest grade.

So a controller that would allow me to set more than two grades for a single print is something I wouldn't particularly value. As long as it doesn't get in the way of some straightforward printing, I wouldn't mind the option being there. I'd just never use it. Heck, I extremely rare use the split-grade functionality on my enlarger controller; let alone a system that would let me set more grades than that.

 

[DREW WILEY]

All of it is straightforward once one gets accustomed to these particular approaches, and as long as their equipment itself functions reliably. But fancy push-button electronic controllers can introduce their own issues in that respect. Sometimes,
the simpler, the better. Just like cameras, the more bells n' whistles an enlarger has, the more problems it can potentially develop.

 

[albada]

Here are two examples from my own work:

• Wood support-structure (in deep shade) under a water tank lit by sun. I dodged green out of the understructure, leaving it lighter and contrastier.
• Burning white sky down to mid-tone. Instead of burning with blue (grade 5) to make the clouds more dramatic, I burned with green (grade 00) to avoid leaving burn-lines in trees protruding into the sky.

In both of these cases, I burned/dodged at the extremes. But with the trees in the second example, I might have wanted to try burning with higher grades to determine at which point burn-lines became visible. Such a case suggests the controller should let the user set the grade to burn with (like the conventional way), instead of what to burn to as I proposed in the OP.

Mark