Wayde, I hate to sound stupid in front of all these people, but I don't
understand what you're saying. If you change only one variable, and leave
everything else constant, then you see the effect of changing that
variable, no?
If you put dabs of pigment-in-gum on the paper without dichromate, and
then do the same pigment and gum *with* dichromate, you have changed one
variable. It's true you have to decide whether to increase the pigment so
that it's the same relative concentration, or cut the gum volume so you
stay with the same total volume of liquid. But those are NOT crucial
variables, as the absence of the dichromate is.
That first test I suppose would be still without exposure. To add
dichromate *and* exposure would be two variables. Of course as noted,
that's what you'd have to do in order to have a meaningful gum test in any
event.... so I'd suggest scrapping the nonsense of the gum and pigment
alone, and start fresh. That's NO variables for the first test, just pick
your amounts and times. Or am I missing something? I guess I am ;- (
Tho I'll mention that I've standardized gum tests at 100 units exposure on
the NuArc and one hour still development. Saves a lot of writing notes,
when exposure and development are not the variables being tested... if
they are, I do 3, 6, or 9 strips at a time, to get all the variables at
one shot.
> Actually I wasn't trying to ague that. In fact I think we're probably in
> fairly violent agreement. What I was trying to add is the observation
> that such failures in experimental design and interpretation are not
> uncommon.
As we see..... ;- (
,
,
>
> > Another issue that I didn't get into in my overly long post about the
> > "Ansel Adams" gum chapter was the assumption that there CAN be an "ideal"
> > emulsion. It totally depends on everything else, such as which layer
> > you're doing, one of many, or a single, what you want it to do, how you're
> > going to develop it and what's under it -- not to mention one of the most
> > important variables of all, namely what paper you're putting it on.
> > Different sizes and textures of paper take emulsion differently.
>
> No argument here.
>
> Oh, by the way. After reading your article on gum printing in your
> "Journal of Post Factory Photography" I was able to make a decent gum
> print. I liked it anyway. Thanks - I think <grin>.
And after making a "decent" gum print, you could bear to do anything ELSE?
Say not so...
cheers,
Judy