[pure-silver] Re: Test of Efke Direct Positive Paper

I would say so ...

The common sunny 16 rule being f/16 1/100 100ISO, then you exposed 200 times 
more, that should make a 0.5 ISO for your paper.

Claudio Bonavolta
http://www.bonavolta.ch

----- Message d'origine -----
De: mmagid3005@xxxxxxx
Date: Tue, 19 Aug 2008 11:17:34 -0400
Sujet: [pure-silver] Test of Efke Direct Positive Paper
À: idcc@xxxxxxxxxxxxxx, pure-silver@xxxxxxxxxxxxx

>I purchased a package of the Efke Direct Positive B & W Positive Paper from 
>Freestyle a couple of months ago.  Freestyle claimed the ISO was approximately 
>1 to 6.  To test the ISO I loaded the paper into film holders ands exposed 
>them in a Miniature Speed Graphic, which has a pretty accurate Supermatic 
>shutter.  The day measured to be a perfect Sunny 16 on my Gossen Luna Pro 
>meter.  I made a series of exposures at f/16  starting at 1/2 second, then 
>doubling the time for each successive photo.  I developed the prints in Ilford 
>developer, 1:14, for 1.5 minutes.  I scanned them on my Epson 1680 at 96 dpi, 
>with no manipulation.  The results are shown at this Flickr site :
>
>
>
>http://www.flickr.com/photos/29332295@N03/?saved=1
>
>
>
>
>It appears the 2 second exposure is the best, though a finer test from 1.5 to 
>2.5 sec. would be useful.  But assuming the 2 second exposure is right-on, 
>then the reciprocal of 2 should be the ISO, or 1/2, for an ISO of 0.5.  Am I 
>correct in this?  The next project with this paper is to use it in my Gordon 
>Street Camera, sometime this fall.
>
>
>
>
>The other photo on the site is me in my darkroom with my Folmer & Schwing 4 X 
>5 aerial camera, circa WWI.
>
>
>
>
>Marty 
>
============================================================================================================To
 unsubscribe from this list, go to www.freelists.org and logon to your account 
(the same e-mail address and password you set-up when you subscribed,) and 
unsubscribe from there.

Other related posts: