Digital BW, The Print

At 02:11 PM 1/8/2003, you wrote:
>Another wierd thing about digital cameras- camera processing software
>does have an impact of how the image looks. I have an associate at an
>in-house studio and he was
>photographing sinks on a grey laminate surface for a catalog. He was
>using a Nikon D1x with a manually set exposure of ƒ8 @ 1sec under
>studio lighting. A grey stainless sink
>looked perfect on the monitor and densitometer readings read ok. He
>swapped out to a white sink, (a common technique when doing high
>volume catalog work)did not change
>lights or exposures and the resulting photo of the white sink was
>darker. The grey backgrounds did not match. It appears that chips may
>be influenced in part by the subject
>matter, and the camera processing software seems to want to take hold
>of the image and fiddle with it even when exposing manually.
>
>John Luke

I had exactly the same thing happen to me this weekend and I've been 
wondering what caused it. I was photographing dental appliances on a 
plaster model of a lower jaw for a local orthodontic lab. Manual exposure 
settings and an umbrella flash with the model sitting on a light table. 
About half of the appliances were just swapped on and off the same jaw 
model, while the other half were on their own models. The exposures using 
the same model with different appliances were pretty consistent, but when 
swapping both appliance and model I sometimes had to open up or close down 
a stop to get the right exposure. I couldn't figure out what was going on, 
but now with your post I surmise that the models varied in their whiteness 
and this variation must have caused the camera to modify the capture 
parameters, even with manual exposure. I wonder if capturing in raw mode 
would have helped this?

Stan

================================
Photography by Stan McQueen
http://www.smcqueen.com