Digital BW, The Print

Just 'expose to the right' for maximum signal capture to constant noise
level.  Do your "placement" back at your desk.


> From: Truman Prevatt <tprevatt@...>
> Reply-To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Date: Thu, 07 Jul 2005 12:38:59 -0400
> To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Subject: Re: [Digital BW] Digital vs scan for BW Print
> 
> The difference between film and digital is (excause the abuse of the
> term) how the grain shows up. In film the grain tends to show up at
> higher light leves - zones 6 up. In digital the "grain" which is really
> noise shows up at the lower levels - zones 3 down. The difference comes
> from different physics producing the effects of grain. In the digital it
> is the preamp noise that would be there - even assuming the sensor was
> noise free. The signal levels are simply closer to the noise floor and
> as such the values are impacted more my the noise than the high level
> signals resulting from bright objects. In other words in the shadows the
> signal to noise ratio is low while in the midleves up it is high.
> 
> As long as you have a pre amp and ADC in the circuit there is no way to
> eliminate this fully. As Paul noted placement of values is extremely
> important because of this and I suspect for critical work no mater how
> good they are the in camera meters are not sufficient and a good old
> fashion spot meter would prove very helpful. When I am doing critical
> work - be it with my 4x5 field camera or my digital - I use my spot meter.
> 
> It is very interesting to think that Adams developed the Zone System in
> order to get proper placement of values on film so as to control the
> highlights (minimize blocking and grain). With a digitial camera it is
> just as useful except in this case it is to minimimize the impact of
> noise on the shadows.
> 
> Truman
> 
> Paul Roark wrote:
> 
>>> ... are you saying that if you had been using film, you could
>>> have gotten the same or better results with a single exposure? and
>>> less manipulation?
>>>    
>>> 
>> 
>> I'm not sure about the single exposure.  I didn't have my spot meter with me
>> for the digital shot -- a mistake I won't make in the future.  Given the
>> "slide-like" 7 stop dynamic range, I'm going back to carrying my Pentax spot
>> meter.
>> 
>> Medium format, Tech Pan film would probably have ended up making a better
>> image with less manipulation, however.  Also, I would have been able to
>> print larger than 16x20 with MF TP.
>> 
>> MF Tmax 100 would probably not have made as good an image, however.  The
>> grain in the foggy parts of the image would have shown.  With the Canon 8 mp
>> image, the foggy areas are totally smooth, and I really like that.
>> 
>> Paul
>> www.PaulRoark.com
>> 
>