Kodak's "Development Numbers" Vintage Darkroom Guide

[Paul Verizzo]

As one who has spent decades trying film and developers with no official suggestions for ideas that interest me, well, well, well.

I was cleaning up my shelf of photo books and literature came across this 1980 Kodak Darkroom Data Guide. I'm about to do another long run of tests/fun/frustrations and I immediately wondered if The Great Yellow Father had any thoughts on this matter, and sure enough, he does! The guide assigns a "Develop Number" to some films and developers, see the picture. Sadly. for this purpose, many of them have gone to that great Kodak graveyard leaving only nostalgia to tease us.

I've toyed around with the concept myself. The only one I can remember with certainly was wanting to develop Plus-X in DK-50. I can't remember if it was stock or 1:1. The DK-50 data sheet lists time for Tri-X, just like this guide, with PX Not Recommended, for what reason I can't fathom. Anyway, I used the D-76 times for PX and TX and then did a ratio to get a DK-50 time. It was perfect.

Anyone have any Development Number experiences or thoughts?

One thought I had about potential error is that hydroquinone has a very steep temperature reaction. That may not be the proper term. In other words for every degree of temperature change, it changes more than metol. Might there be a difference in accuracy with these DN's between a normal MQ developer with a lot of HQ compared to the much lesser amount in DK-50? I'm probably overthinking this......

 

[MattKing]

Looks good to me Paul.
I've been using one of those for just about forever.
T-Max 100 and T-Max 400 have a standard Development number of 38 in my working strength batch of replenished XTol.
The last couple of rolls I boosted the contrast slightly - used a Development number of 40.
The notes on each negative holder sheet in my developed negatives binders include the Development number I used. No need to seperately list time and temperature.

 

[Paul Verizzo]

Looks good to me Paul.
I've been using one of those for just about forever.
T-Max 100 and T-Max 400 have a standard Development number of 38 in my working strength batch of replenished XTol.
The last couple of rolls I boosted the contrast slightly - used a Development number of 40.
The notes on each negative holder sheet in my developed negatives binders include the Development number I used. No need to seperately list time and temperature.

I walk in the shadow of the master. Thanks! Since TMY is one of my top shelf films, thanks for those numbers.

 

[MattKing]

I walk in the shadow of the master. Thanks! Since TMY is one of my top shelf films, thanks for those numbers.

That working strength batch is an old one, so I'd suggest that as a starting point.
My guide has a few pasted in notes on the page where all the films are listed showing the numbers for film and developer combinations I've arrived at over time. I should probably make it prettier!