Digital BW, The Print

Greg wrote:
> --- In 
> DigitalBlackandWhiteThePrint@yahoogroups.com, "scott_now_coming" 
> <scott_now_coming@...> wrote:
>> I think it comes down to price vs quality: value.
>>
>> For $800 for a scanner like the V-750 that will scan up to 8x10" 
>> films up to 6400 dpi, how can you go wrong?
>>
> 
> 
> All I know is that I'm in the market for a new flatbed scanner, and 
> I'm not doing anything until the v750 reviews come out, and maybe 
> some time after that. I still have to wonder if the 6400ppi is going 
> to be real or the normal over inflated value that Epson is pretty 
> well known for.

I expect that the Epson V750-M will have a true resolution 
somewhere between 3000 and 4000. probably closer to the 3000 
side. That isn't much lower than the 3600-3800 of the Nikons. 
The Dmax and dynamic range may proof to be equal to the Nikon 
8000-9000, the older Epson models already came close in German 
ISO tests. The tube light source may result in more flare + 
noise, on the other hand the oversampling + the tube light 
source may prove to be nicer for B&W grain. Signal/noise can 
only be measured in a good ISO test and there's a relation 
between S/N and available resolution / film size when printing 
big sizes. Noise doesn't always show in the print.

The focus issue is one thing to check. With wet mounting you 
can reasonably well keep the (larger) film flat and at the 
right focus distance from scan to scan. That focus finding 
should be better than the 3 choices Epson hardware gives. 
There's something I worry about more, if the scanner has done 
several scans and warmed up I would like to know what changed 
in the focus distance. The former models had a plastic shell 
and the engineering had the sensor, traction etc fastened to 
the bottom on a metal plate. The glass is at the top of the 
plastic shell. It wouldn't surprise me if the 8 cm height of 
the shell gives a focus shift of 0.5 mm after 20 scans. The 
V700 etc seems to have a metal shell which would make it 
better. There are some other ways to compensate temperature 
influences. Without active focusing this becomes a thing to 
control. I have seen some neat designs where the sensor 
carriage actually rides against the glass (springs for some 
pressure)  to keep the distance equal to the original. That 
was on a cheap reflective scanner.


Ernst

-- 

                    --
           Ernst Dinkla


www.pigment-print.com
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