From: Ken Watson (watsok@frii.com)
Date: 12/02/02-09:30:00 AM Z
You are correct. In most cases this is always better as you have a
relatively high quality scan resident on your computer that you can then
reduce in size.
Most sensors today use staggered rows for each color inside the sensor. So
there are 2 rows each of red, green ,and blue. This has been the case from
about 1200 DPI up due to cost constraints. What is going on internally at
reduced resolutions is they are using only one row of the stagger and
dumping the other to speed things up. With today's consumers, the speed of
the scan has great weight to many users. So manufactures do what ever they
can to speed things up at lower resolutions. This does not always equate to
higher quality.
----- Original Message -----
From: "Sandy King" <sanking@clemson.edu>
To: <alt-photo-process-l@skyway.usask.ca>
Sent: Sunday, December 01, 2002 1:00 PM
Subject: Re: Warning: Digital Question
> Ken wrote:
>
> >
> >Perhaps there is information about how the software handles different
> >resolutions in the manual. A way to see for yourself is do a scan at
> >2400DPI resolution and another at 300. If the 300 DPI scan is faster (
> >takes less time )there is a good chance that there is a lot of info being
> >dumped. Try to determine if Epson specifically states they have an
> >additional set of color stripes / sensors for doing lower image
resolutions,
> >which I strongly suspect is not the case. If they do have additional
sets
> >of sensors then the above speed test is invalid.
>
>
> Nothing in the manual about any of this but I did the test you
> suggested and the scan was much faster at 300 dpi, after adjusting
> for re-sizing, than at 2400dpp at 100% ratio. So this would suggest
> that I would be better for scanning at 2400dpi and re-sizing later,
> right?
>
>
> Sandy King
>
>
>
>
> >
> >
> >----- Original Message -----
> >From: "Sandy King" <sanking@clemson.edu>
> >To: <alt-photo-process-l@skyway.usask.ca>
> >Sent: Sunday, December 01, 2002 10:57 AM
> >Subject: Warning: Digital Question
> >
> >
> >> I have a scanning resolution question.
> >>
> >> Situation is this. I am scanning a 4 X 6.5" section of a 5X7" color
> >> negative with the Epson 2450 flatbed scanner, which has optical
> >> resolution of 2400 dpi, using SilverFast scanning software as a
> >> plug-in to PhotoShop. The eventual purpose of the scans is to make
> >> color prints approximately 13X19" in size, or to make negatives for
> >> alternative printing. I understand that a maximum resolution of a
> >> little over 300 dpi at the printing size is needed for either purpose.
> >>
> >> My question is this. What are the pros and cons of of the two
> >> following scenarios: 1) scanning at 100% of the 4 X 6.5" negative
> >> size at the maximum optical resolution of 2450 dpi, re-sizing later
> >> in PhotoShop, or 2) scanning at the desired printing size of 13X19"
> >> 300dpi?
> >>
> >> Sandy King
> >>
> >>
> >>
> >>
> >>
>
>
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