U of S | Mailing List Archive | alt-photo-process-l | RE: Density Base OHP and Stouffer

RE: Density Base OHP and Stouffer



My measurement with a densitometer in UV mode gives the following.

Stouffer 21-step tablet, Step 1 = 0.10
Stouffer 31-step tablet, Step 1 = 0.10
Pictorico base, 0.18
Crystal Clear (PhotoWarehouse) base, 0.06

Sandy King





At 3:48 PM +0200 11/24/06, Loris Medici wrote:
I don't have a densitometer too but I clearly remember people reporting base
density of Pictorico as something like log 0.15, and most graphics films -
like the ones that Stouffer use - base density is something like 0.05.
Therefore there should be around 1/3 stop (0.15 - 0.05 = log 0.10) STP
difference between the two. I use Photowarehouse Ulfrafine Crystal Clear
transparency and I think its base density is something like 0.10 (0.05 less
than Pictorico) and this is completely consistent with the facts: a) My
printing times w/ Ultrafine are faster than w/ Pictorico b) When I put the
transparency material over the Stouffer step tablet (31-steps) so that half
of the tablet is covered (that way I can see the density difference between
the Stouffer tablet alone and Stouffer tablet + inket substrate - I think
this is covered in Mark's book, IIRC that was a trick that Sam Wang
suggested) I get exactly 1 step difference between the two. Just use the
trick mentioned in (b) and you'll see how many steps difference you get with
your material... From that point, its easy to calculate the necessary
exposure adjustment.

Regards,
Loris.

-----Original Message-----
From: Michael Koch-Schulte [mailto:mkochsch@shaw.ca]
Sent: 24 Kas×m 2006 Cuma 05:39
To: alt-photo-process-l@sask.usask.ca
Subject: Density Base OHP and Stouffer

I don't own an actual densitometer. My scanner coupled with VueScan puts
Pictorico OHP at either LogE of 0.08 or 0.10 and it puts my Stouffer
tablet's Step 1 (clear base) at between 0.04 and 0.06. Does this sound
close? Do most people use 0.04 or 0.05 (or something else) when calculating
the printing time between the two? 0.05 is a bit more convenient because
it's 1/6 of a stop. The resulting error is rather small but I'm just
wondering. Thx.