Creating a larger fiber print on different paper from a smaller RC print timings. Workflow options with split grade printing?

[Alex Benjamin]

Let's say I wanted to go from a Ilford 8X10 RC final print to a larger fiber Print (still Ilford) and I made the RC print using split grade filtering. What is/would be your preferred workflow?

This might help thinking about your workflow going from a small size to a larger one.

The maths is very simple, but you have to use the same paper on 8x10 that you'll be using in the larger size.



Should work regardless of whether you're doing "normal" or split-grade printing.

 

[DREW WILEY]

Sure the math is simple. Or you could just use a simple lux meter before and after adjusting enlarger height.
Doesn't mean you'll necessarily get the same "look" aesthetically, however. And it makes more sense to do a simple strip test than sacrifice a whole sheet of paper to find out.

And anytime you significantly increase the size, you're also inherently decreasing the contrast. So there's that factor to take into account too. That video doesn't say a word about that fact.

 

[Alex Benjamin]

Doesn't mean you'll necessarily get the same "look" aesthetically, however. And it makes more sense to do a simple strip test than sacrifice a whole sheet of paper to find out.

And anytime you significantly increase the size, you're also inherently decreasing the contrast. So there's that factor.

Agreed. The mathematic formula just helps to figure out your starting point, time-wise.

And this is also where an f-stop timer becomes practical, since burning or dodging 2/3 stops remains burning or dodging 2/3 stops no matter what size your printing.

Again, all this only works if you're using the same paper on all sizes.

 

[DREW WILEY]

One more reason I don't like to be straightjacketed by a set development time. Give the bigger version a little longer development, and it might allow you to keep the same filter settings.

 

[GregY]

I think you may be attributing different things to a split grade approach than I do.
Split grade does two things for me:
1) it allows me to choose any "grade" of contrast within the wide range of contrasts available from the paper and your light source, including what might be described as "fractional" grades; and
2) most importantly, it permits printing different parts of the negative with differing amounts of contrast.
Neither of those is particularly applicable to the issue you raise in this thread, although I guess the ability to make fractional grade adjustments is probably of some use when trying to respond to the different responses of the two types of paper.

I agree Matt.... the question of split grade printing (or not) is a question apart from trying to make a large FB print based on data from a small print on RC paper.

 

[ChrisArslain]

Agreed. The mathematic formula just helps to figure out your starting point, time-wise.

And this is also where an f-stop timer becomes practical, since burning or dodging 2/3 stops remains burning or dodging 2/3 stops no matter what size your printing.

Again, all this only works if you're using the same paper on all sizes.

this exactly explains why I’m interested in getting an Fstop timer. Once you have a base exposure you can always calculate on your own but those timers seem like they make life easier.