Re: light source basics question

Hi Dwaine,
I just finished installing my 1000 watt metal halide lamp.
By the way, I installed on top of a trolley so I can move the lamp to use it
anywhere, on the bottom of the trolley (5 feet tall) I have two removable
trays to put the contact frames.
I am doing exactly as it is explained on Sandy article and using 30 inches
for a 14x11 print on canvas 16x20.
It works as when I print using sun exposure thru my window glass in my
apartment in NY.
So far very good and no problems but I have been working with it for two
days only.
Remember never touch the bulb.
I also follow most of the advices given on the Livick manual but I like
better to use cianotype for the cyan color.
Regards
Giovanni

----- Original Message -----
From: "Dwayne Sandall" <sandall@shaw.ca>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Tuesday, September 21, 2004 10:37 PM
Subject: light source basics question

> Hi all,
>
> I am in the midst of assembling the equipment I need for starting gum
> printing and I have a question about my choice of light. I have
> decided to go with a 1000 watt metal halide grow lamp, but I have two
> questions.
>
> 1. What is the optimal distance from the contact frame for this type
> of light? Somewhere I got the idea of 40 inches, but that might have
> been as a result of a certain amount of falloff and hence, making
> sure the hotspot of the light hit the contact frame. In my case, I
> plan on doing most of my gum prints smaller than 11 x 17, although I
> might do some longer panoramas, up to maybe 24 inches long and about
> 6-10 inches wide. I'm making a 16 x 30" contact frame, but I might
> also make a smaller one too, see how things go.
>
> 2. What is a good time range for starting exposure tests? I think it
> was in Sandy King's article on unblinking eye that I read exposure
> tests where for 5 minutes using this light type. Obviously the time
> is going to be related to the distance from the light to the
> negative, but I am just trying to establish a baseline for starting.
> I am using the chemicals recommended in Livick, so potassium
> bichromate.
>
> Thanks all for your help!
> Dwayne
>
> --
> Dwayne Sandall
> It is not because things are difficult that we do not dare; it is
> because we do not dare that they are difficult." -Seneca
>
Received on Wed Sep 22 16:22:26 2004