Re:Stouffer wedge (was VDB is "Brownprint" process?)

Susan,

One of the early issues of Post Factory Photography had an excellent
article, by Judy herself as best I recall, on the use of a step wedge
in alternative printing. You should try to get a copy of the article
as it really is great as a practical application of sensitometry.
Someone mentioned this article not long ago but you may have missed
it.

You can actually buy calibrated T2115 step wedges from Stouffer for
about $20 or so, but unless you are doing a lot of film testing and
need a lot of precision the calibrated steps are a waste of your
money. The steps do vary a bit, even from the same batch. I recently
bought four more of the T2115 step wedges and they are all slightly
different at Step 21, ranging from a low of 3.06 to a high of 3.09.

Calibration just means that someone with a calibrated densitometer
has read each of the 21 or 31 steps and you get that information.

Sandy

>>At 05:16 AM 2/23/06 -0800, Susan Huber wrote:
>>
>>>BTW; does one need a 21 step wedge for alternative processes and
>>>how does one use it?
>>>I went into the store yesterday and found out the Kodak step wedge
>>>costs $144. US and the Stouffer wedge costs $5.80 US- a big
>>>difference in price, any difference in quality?
>
>Kodak has (or had) a less expensive step tablet, about $18 in the
>US. The $144 tablet, whatever it costs in the US, is probaably
>*calibrated.* That is, minor variations in actual density, either
>from batch to batch or even from strip to strip, occur in the
>making. My understanding is that "calibrated" step tablets have
>actual density of each step read & recorded.
>
>AFAIK this matters in rocket science (possibly).
>
>J.
Received on Thu Feb 23 14:46:06 2006