[alt-photo] Re: Is this mailing list still active?

[sam wang]

Hello Kurt,

From my experience many years ago, the filter factor would be 3 stops. When you do it with pinhole and the films you mentioned, you might run into reciprocity problems even if you shoot in bright sun.

Since you haven't done much gum yet, I would suggest limiting your variable - try some monochrome gum first, then some multi-color gums with a single negative by varying exposures. Starting out with 3 in-camera pinhole separation negatives could end up with too many things going wrong and not knowing how to pinpoint the problems. I know, it sounds terribly slow going, but unfortunately, as the story goes, "there is no shortcut to Carnegie Hall."

On the other hand, even though digital negatives made printing a lot easier, some of my best gums were made with fogged in-camera negatives. 

Sam Wang


On Mar 27, 2011, at 7:38 PM, Kurt Nagy wrote:

> 
> Sorry, didn't see this Gordon.  Kinda hard to keep track of the responses when they come in quickly.  Is there a way to
> respond without keeping the original email and/or creating a new "thread"?
> 
> Yes, my ultimate goal for producing images will be tri-color seperations via pinhole using black and white negatives.  I have good luck
> with Ilford products and all my 4x5 images are shot using either Delta 100 or HP5 400.  
> 
> I initally decided to do gum because when I shoot color film I can develop it at home but I don't know how to make a C-print.  Wanting to stay away from printing my negatives digitally I found an article explaining how to make color images using black and white + photoshop, little bit more digging revealed the 19th century color photos by Sergei Mikhailovich Prokudin-Gorskii.  He didn't actually make prints but projected them together to form color but it got me interested.  I wanted to do dye transfer but that is
> all but impossible to find info and materials on, so gum bichromate it is :)
> 
> I already have my set of Lee color seperation filters, according to their materials they have a filter factor of 1-1 1/2.  I just haven't had a chance to run any tests.
> 
> Do you have any of your images posted online to see?  I'd love to see your results
>