arista.edu ultra fb vc fiber inconsistency

[strangepics]

Hello.

I've been using this (arista.edu ultra fb vc) paper in 8x10 and 11x14 format, and noticed the following inconsistency between the 8x10 box paper and 11x14 while printing a very thin (but printable at grade five) negative:

8x10 takes about a third of the 11x14's exposure time longer to get the same density, but has much better contrast (at grade 5).

The 8x10 paper's contrast for this negative is great, it is the contrast I want for the 11x14 print from this negative. Very disappointing, needless to say.

Why such a difference, and should I expect this behavior to be consistent for this paper between formats?

What is, in your experience, a VC paper that gives greatest contrast at grade 5?

Thanks!

 

[pwitkop]

With an 11x14, the enlarger head is farther above the paper, and light falls off as an inverse square of the distance (inverse square law), so as you raise the head for a larger enlargement you need more light (longer exposure, or bigger aperture). A bigger enlargement can affect the contrast of the negative, in my experience it's not a big change, but there is an effect. Also different emulsion batches can vary slightly in contrast an sensativity, again not a big change, but a few small changes in the same direction can add up.

Peter

 

[dpurdy]

It is possible that 11x14 ultra doesn't sell nearly as well as the 8x10 and the batches are very far apart in time they were made and the 11x14 might even be getting old enough to lose some contrast. You could ask them at Freestyle though I don't know if Freestyle reveals all that or not.

I use Arista and often go from 8x10 to 16x20 and I generally need to boost the contrast 2 tenths of a grade on my Aristo VC head.

 

[strangepics]

With an 11x14, the enlarger head is farther above the paper, and light falls off as an inverse square of the distance (inverse square law), so as you raise the head

That's not the problem - I am aware of the inverse square law. I specifically did not raise the head. What really happened is I assumed the 8x10 will be exactly the same, and used it as a test strip for the 11x14 print.

Could someone please recommend great contrasty VC paper so I know what to buy for grade 5 printing of thin negatives?

 

[strangepics]

It is possible that 11x14 ultra doesn't sell nearly as well as the 8x10 and the batches are very far apart in time they were made and the 11x14 might even be getting old enough to lose some contrast. You could ask them at Freestyle though I don't know if Freestyle reveals all that or not.

I use Arista and often go from 8x10 to 16x20 and I generally need to boost the contrast 2 tenths of a grade on my Aristo VC head.

The change I saw is more like 2/3 of a stop, also the 11x14 needs _less_ exposure to reach the density for the black than the 8x10! Doesn't this mean that the 11x14 is faster than then 8x10?? AFAIK paper slows down and loses contrast as it ages, not the other way around. Perhaps the 8x10 is a whole different paper, or there is a strong manufacturing difference batch-to-batch? These former SU companies aren't known for great quality control.

I also compared the 11x14 with Kentmere fineprint 11x14, and that is even faster paper and not contrasty either.

 

[fschifano]

Could be that there is a large batch to batch variation. Who knows what the QC is like? After a few boxes of the stuff, I've seen some differences myself. It's no big deal, I just test each box and note the characteristics. The price is right. I can live with the discrepancies.

 

[dancqu]

... but has much better contrast (at grade 5).

Grade 2 Slavich will just make grade 4 using
a condenser enlarger and high contrast developer.

I think Grade 4 Slavich with a diffusion enlarger and
Dektol or the more contrasty Beer's 7 developer will
make Grade 5 or better. Freestyle has Grade 4
Slavich GL or Matte, SW and FB, 11x14,
in 10 sheet packs. Dan

 

[strangepics]

Grade 2 Slavich will just make grade 4 using
a condenser enlarger and high contrast developer.

I think Grade 4 Slavich with a diffusion enlarger and
Dektol or the more contrasty Beer's 7 developer will
make Grade 5 or better. Freestyle has Grade 4
Slavich GL or Matte, SW and FB, 11x14,
in 10 sheet packs. Dan

Great, thanks. Have you tried Fotokemika EMAKS? Is it very similar?

 

[dancqu]

Great, thanks. Have you tried Fotokemika EMAKS?
Is it very similar?

Slavich is very contrasty for it's Grade. Not so with
Emaks. While a Grade 2 Slavich in a soft developer
starts out Grade 3, a Grade 2 Emaks in the same
soft developer prints Grade 1.

Currently I'm using Emaks with a roll of overly
contrasty negatives. Lays flatter out of the box
than any other FB paper I've used. Dan