🚀 go-pugleaf

David J. Littleboy wrote:

> "Chris" <Chris@swift.com.au> wrote:
> 
> 
>>When the Epson ???? was released they quoted something like 800x1600 
>>resolution the resolution in which the 1600 was double stepped to appear 
>>like a 1600 scanner. But still the true resolution was still 800 dpi. 
>>(There must be an explanation somewhere on the web how they come to these 
>>figures.)
>>
>>I always only accept the smaller number as being the true optical 
>>resolution.  Still 4800dpi is more than enough resolution for 35mm film.
> 
> 
> The smaller number is still a funny number. Epson uses an "offset" CCD that 
> consists of two half-resolution CCDs offset by 1/2 the pixel pitch. The 
> result is that instead of the theoretically optimal point sample, it samples 
> each pixel with an area much larger than the pixel size for the nominal 
> resolution. The good news is that this should reduce grain aliasing, the bad 
> news is that the resolution MTF is abysmally low above 1/2 the nominal 
> resolution, so the appearance is a lot more like what you'd expect from a 
> point sampling scanner with 1/2 (or less) the resolution.
> 
> The new Epson scanner appears to be playing the same game.
> 
> http://photo-i.co.uk/News/Feb06/Epson_V700_scanner.htm
> 
> (I almost always find that those guys get much better results from Epson 
> scanners than anyone else does. Still, it looks pretty good.)
> 
> Also, the 6400 dpi is good through 4x5, so maybe 4x5 users with 64-bit PCs, 
> tens of GB of DRAM, and a lot of time will be amuzed...
> 
> David J. Littleboy
> Tokyo, Japan
> 
> 

Yep that could be correct with the quoted resolution. Just knew they 
played with the figures to make them look better than the actual 
straight optical resolution. (Not taking away quality but its the 
consumer deception of how the figures are calculated)