Digital BW, The Print

Michael King wrote:
> You got me excited, but unfortunately they are only 12 bit backs.
> I think at least 14 ideally 16 bits is a must for good tonality.
>
> Mike
>   
I hate to be a contrarian, but I actually happen to own a Megavision E4 
monochrome (16 megapixel, 37mm square 4096x4096 Kodak sensor) which I 
use on my Bronica ETRS. I also have a Better Light Super-6K scan back 
(150 megapixel, colour, 8000x6000, trilinear array sensor). The Better 
Light has a 14 bit ADC, I think, whereas the Megavision has a 12-bit 
ADC. In both cases, the tonality is way beyond good enough, to the 
extent that I've been able to use HDR-style post processing on single 
shot captures to great effect. Basically, neither back is at all lacking 
for dynamic range or noise control. As for resolution, particularly when 
printed, despite the large difference in pixel count, there is little to 
choose between the two backs in terms of perceived resolution unless you 
go to a very big print. Bronica glass tends to be very sharp indeed, so 
with a little care it is possible with nearly any of their lenses to 
resolve down to single pixels. I've had particularly outstanding results 
from the 30mm fisheye, 40mm MC, 75mm PE, the 100mm MC macro, the 45-90 
zoom and the (awesome but extremely rare) 55mm PE shift/tilt, but this 
is probably because they tend to be my most often used lenses anyway.

Down at the pixel level, a well-focussed image from either back is very 
obviously superior to B&W conversions from a Bayer-pattern sensors, 
particularly when you are using contrast filters. In B&W, I usually end 
up using some kind of contrast filter, often a deep red or deep orange, 
or its RGB emulation. Neither the Megavision or the Better Light lose 
any resolution or signal to noise ratio as a consequence of this, so the 
difference in the resulting prints can be quite startling.

I've never once had anyone ding my prints as lacking tonality -- quite 
the reverse, actually! One particular print I made from a Megavision 
image won club and area competitions and ended up hanging in a gallery 
for a while, so what can I say? These things actually work!

Sarah