Compensating for Ilford contrast filters

[Alexandra]

So looking at Ilford's technical sheets for their contrast filters, I see they recommend no adjustment for filters 00-3.5, and double the normal exposure for 4-5.
Now, I can vouch for the latter part - double the normal exposure has been a reliable starting point for 4-5.
I haven't been using the lower grades much though. I usually develop my negatives to have higher than normal contrast to begin with.
But based on the times I did try them, I find there still needs to be some adjustment... The prints are overall too bright.

Has anyone come up with or come across a compensation system, or some rule of thumb for them?

Thanks,
Alex.

 

[amolitor]

I have actually found the recommendations to be pretty much spot on, using MG IV and a set of Ilford filters and an incandescent lamp.

Your mileage apparently varies!

Usually I don't shift grades very far, though. My first guess is usually within a grade, often half.

 

[Alexandra]

Could it be my negative density?
The very reason I need the filters is I tried a new developer and everything came out somewhat flatter than I'd like. So in that case I suppose the shadows could be affected more than they normally would be...

 

[amolitor]

I have to say I am a little confused. If you develop your negatives to greater contrast than normal, wouldn't you need a lower contrast grade when printing? And vice versa?

Anyways.

When I change grades, I always recheck and tweak the exposure a little. I find that contrast grade "mostly" leaves the highlights alone, and pushes the darks up and down, which I use as a guide, but it's definitive. My process is:

1) look at the negative, guess at the necessary contrast grade
2) dial in exposure pretty close with some tests
3) evaluate contrast and change the filter if necessary, this is usually 1/2 a grade or 1 grade at most (usually!)
4) think about what my new exposure ought to be, factoring in:

a) Ilford's 2x rule for grades 4-5​

b) my own understanding of how the highlights stay fixed and blacks change​

5) run a test with a quite narrow range of times, for example, I might go 10 seconds/12 seconds/14 seconds if my guess in step 4 was 12 seconds.
6) re-evaluate contrast and exposure

usually at this point I am pretty much where I want to be, maybe I decide that 13 seconds is right, and that the contrast grade is also right.

Now I start trying to pull final prints.

 

[timor]

I haven't been using the lower grades much though. I usually develop my negatives to have higher than normal contrast to begin with.

Hi Alex. First, what do you call "higher grade" and what "lower grade" ? Is this similar to lower and higher contrast ? If so I am not sure how do you develop your negatives. After that, all, what Amolitor said, but if you really want to avoid this a bit prolonged procedure get yourself some darkroom light meter for enlarger. You will avoid the compensation confusion and after some calibration (nothing complicated) you will be spot on or very close to it with the first print.
Anyway what is your usual developer and which one are you trying now ?

 

[Alexandra]

I usually shoot tri-x and develop in D-76 but I make it quite a few degrees hotter than it needs to be (usually around 30C).

This time around I tried Rodinal and decided not to take my usual liberties with something I don't know as well...

So if I do things my normal way, I'm usual pretty satisfied with the initial contrast of my negatives and don't need filters. I think until last week I've gone at least a year without them. (I should also say I like a straight print; I don't tend to overwork them) When I do need the filters, it's because the contrast is so flat it can only be salvaged with the #4-5, or extensive split-grading.

And I like stark contrast too, so I seldom wander into the #3.5 and below territory.

Now that I'm having to, I was simply curious if there was an unofficial set of compensation factors going around. After all everyone has their own recipe for developer, and their own rules of thumb for exposure; I figured maybe people don't use the contrast filters "out of the box" either

 

[webestang64]

I have not used those filters in years.

Back when I used those filters I was using the 2.5 3 3.5 filters the most, printing 8x10's only. This was with Ilford multi-grade papers (Kodak I used was graded). I shot a lot of Tri-x (ASA depended on a film speed test first) developed in D-76 normal temp/time, steel reels/can.
My enlarger was a Vivitar 35mm with a Nikon 50mm 5.6 lens. Mostly set at F11.

That was how I got the look I wanted as far as tonal range and blacks. At least I like them......:mrgreen:


But now I'm cold light muti-grade enlarger and loving it! Printing with blues and greens is a whole different look.