[alt-photo] Re: New Platinum Prints

[David Hatton]

Etienne,
Thanks for replying. Just so I understand what you're saying. The
curve I apply to my digital negative is actually destroying some of
the image content of the scanned negative? If so, why do we apply a
curve at all? Why can we not merely print the negative as it is
scanned? Assuming of course that the original negative is correctly
developed for platinum? I'm sorry if I sound stupid but I find this
very confusing at the moment :)
Regards
Davidh


On Sat, Apr 10, 2010 at 11:09 PM, etienne garbaux
<photographeur at nerdshack.com> wrote:
> Davidh wrote:
>
>> This is something that's been concerning me lately. I've been
>> preparing my negs for palladium digitally using Mike Wares method. The
>> reason for this is that my printer (Epson 1400) won't allow me to use
>> any other method as the inks are not very dense. I manage to get
>> satisfactory gum prints but I'm thinking I could be missing out on
>> something in my palladium experiments. My exposure time using BL tubes
>> is 60 seconds. The prints look ok but nothing special. Could this lack
>> of negative density have something to do with the way they look? If so
>> why?
>
> Be aware that I'm not familiar with Mike Ware's method (although I have seen
> prints attributed to it) and I do not use digital negatives.
>
> There are two things at work here: (i) matching the negative density range
> ("DR") to the printing exposure scale ("ES"); and (ii) the character of the
> exposure scale, however long or short it is.  If the DR of your negs is too
> short to match the printing ES, you'll get low-contrast prints with murky
> (but not very deep) shadows and/or fogged-looking highlights.  But even if
> the negs have the right DR for the process, the characteristic curve of the
> printing process may be ugly.
>
> The standard long-scale Pt process has a very, very long linear scale with
> symmetrical, gently rounded toe and shoulder, typically printing the whole
> step wedge with some scale left over.  Therefore, you need to use negatives
> with a very high DR to obtain all of the available print zones with this
> process.  Photographers have not typically made negatives this "bulletproof"
> since the late 19th Century, so folks have tried a number of different
> methods to shorten the Pt exposure scale (adding dichromates, hydrogen
> peroxide, etc., etc.).  These tricks shorten the exposure scale by raising
> the threshold exposure -- not really a very promising way to go about it.
>  Anybody who has done serious sensitometry with the process has seen the
> ugly characteristic curves the short-scale versions of the Pt process
> produce.  I have yet to see prints made using any short-scale Pt process
> that came close to the look of "real" (long-scale) Pt prints.
>  Unfortunately, so many workers are using the short-scale processes now that
> many people don't even know what a good Pt print is supposed to look like.
>
> I commend to you an experiment:  Make some in-camera negatives with a DR
> above 2.1 (try to hit 2.4 for starters), and print them using the standard
> full-scale Pt process.  I bet you never go back to digi-neg Pt printing
> again, and depending on how big you think prints need to be, that you
> acquire one or more LARGE format cameras or learn to make good enlarged
> negatives in the darkroom (not so easy now that slow, blue-sensitive copy
> films are long gone).  If you have no option besides digital, have a service
> bureau make some 2.4 DR negatives with an imagesetter using your files.
>
> Best regards,
>
> etienne
>
>
>
>
> _______________________________________________
> Alt-photo-process-list | http://altphotolist.org/listinfo
>