Focomat V35 split grade with color head (again)

I just got second-hand V35 with color head (in fact, with VC head too, but sadly it needs repair) and intend to do split grade BW printing with it. For the sake of first test I was projecting filter grades using adjustment table from Ilford (https://www.ilfordphoto.com/amfile/file/download/file_id/1933/product_id/733/). I also got a very old set of Ilford under-the-lens filters and was comparing the colors I get with under-the-lens filter vs color head at various grades. I notice substantial difference, especially at middle grades. Say, Grade 2.5 Ilford filter seems to have a lot more magenta than color head produces on corresponding table-based setting (see attached photos).

Would it be a valid method to "calibrate" and come up with my own table based on ILFORD under-the-lens filters? Any other practical suggestions, e.g. could it be that color head needs repair too? (although it looks to be in perfect condition)

Will appreciate any advice.

- Alex

- Alex

Are you using the single filter or the two filter tables from the Ilford datasheet?

When used with no filter, a tungsten bulb will print to roughly a grade #2. The two-filter tables along with filter sets are designed to keep the exposure the same when changing grades.

I also got a very old set of Ilford under-the-lens filters

The operative words here are "very old". To the best of my knowledge (and I may be wrong), filters, both under the lens and built-in, change colors over time.

Are you using the single filter or the two filter tables from the Ilford datasheet?

 

When used with no filter, a tungsten bulb will print to roughly a grade #2. The two-filter tables along with filter sets are designed to keep the exposure the same when changing grades.

I am using two filter table (single filter table appears to not contain the values for Focomat).

I was planning to try simple method explained in one of youtube videos - test strip of 5 exposures with 2 sec steps each (2,4, 6 ...) at grade 2.5, selected exposure, say 8 sec; divide by two => exposure 4 sec in low contrast and 4 sec in high contrast, then adjust exposure/grades as needed. Sounds logical, and exposure manipulations are straight-forward.

I was just confused with sheer difference in apparent color in middle grades as it almost seems as something is broken. Funny part is that lowest/highest contrast is a 1:1 match to Ilford filters in apparent color.

The operative words here are "very old". To the best of my knowledge (and I may be wrong), filters, both under the lens and built-in, change colors over time.

That could be too!

At this point, I guess I just need to give it a go and see what happens :)