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.

 

[Alex Benjamin]

those timers seem like they make life easier

At the risk of restarting the same old food fight, I'll just say that I have an f-stop timer and yes, in many ways, they do.

 

[Carnie Bob]

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.

When I worked at a mural lab in the 80's we had to make different sizes for lightbox or placement size and we used a Mag Formula to calculate the different sizes and worked very well, we did not use analyzers in this lab.

 

[Carnie Bob]

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.

OR -(please do not kill me hear) make digital negatives and make contact prints, then your time, contrast is the same no matter what the size...

 

[GregY]

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.

With the current cost of paper, i'd prefer to buy paper rather than spend $500 replacing a timer.

 

[Nicholas Lindan]

With the current cost of paper, i'd prefer to buy paper rather than spend $500 replacing a timer.

Ah, but spending $300 on an f-stop timer can result in less of the paper going straight into the trash.

DIY projects to make an f-stop timer are all over the web and youtube. One of them uses your smartphone and a blue-tooth enabled plug-in light switch; can't get much cheaper than that. Might want to put a sheet of red filter over the phone's screen - see Rosco lighting filters at B&H.

There is no one solution that works for everyone. Pays your money, takes your choice.

 

[GregY]

Ah, but spending $300 on an f-stop timer can result in less of the paper going straight into the trash.

DIY projects to make an f-stop timer are all over the web and youtube. One of them uses your smartphone and a blue-tooth enabled plug-in light switch; can't get much cheaper than that. Might want to put a sheet of red filter over the phone's screen - see Rosco lighting filters at B&H.

There is no one solution that works for everyone. Pays your money, takes your choice.

NL, Maybe if you don't have much experience in the darkroom, but buying a new timer isn't going to make up for the lack of 10,000 hrs. Perhaps if I were just outfitting a darkroom i'd look at an f stop timer....but those of us who have been printing for decades pretty much have things figured out. & there's not a ton of paper going into the trash... for starters using the same paper for small prints as large prints, or cutting up a sheet for test strips. IMO as always shortcuts aren't always shortcuts. As shown various formulae and reference to the inverse square law takes you a long way. And as mentioned, change in contrast over size increase needs to play into any equation.

 

[MattKing]

I use @RalphLambrecht 's handy f-stop timing table and a timer that isn't an f-stop timer to do f-stop printing - because I already have the timer.
I've wanted one of Nicholas' timer for a long time.

 

[DREW WILEY]

Get cheaper than that, Nicholas? What did the damn Bluetooth Smartphone cost, how often do people keep replacing those things, and what do you pay per month? And who needs something like that lighting up accidentally during a darkroom session?

Like I already said, I just go straight to test strips. But if I did want to use a meter, it would be the one I use for generating very precise enlarged negatives or dupes, internegatives, and color separation negatives, which is actually classified as an easel densitometer, whichis far more accurate at low light levels than a typical densitometer. I also have enlarging meters and a simple lux meter, which could also be used. So I not only know how to do it, meter-wise, but have exceptionally good tools to do so.

 

[MattKing]

I don't think @DREW WILEY is in @Nicholas Lindan's target market demographic

 

[GregY]

I don't think @DREW WILEY is in @Nicholas Lindan's target market demographic

On the other hand....in the world of commerce, if you're selling something....pretty much everyone is your target......