RE: Resolution and Banding

["Laurie Solomon" <laurie@advancenet.net>]

>PS I suppose I could predict that someone will now tell me that a medium-
or
>large-format combo weighs less than my 35mm setup.

I won't tell you that nor will I attempt to argue that one should use medium
or large format in a hand held fashion when shooting. :-)

While I know plenty of professionals who use medium format (645,6x6, 6x7
Mamyia, Hasselblad, and Bronica, and other brand) cameras everyday and a few
who use large format (4x5 and 8x10 flatbed and monorail view) cameras more
than merely occasionally in my area (not only commercial photographers but
also wedding and portrait photographers) with most buying their film from
large professional vendors (like Calumet and B&H) and not the local camera
store, the point of my argument was not to convince you to switch to 35mm
but to suggest why some of those who use film scanners can wind up with
spare pixels above the 380ppi when scaling the image to 8x10 from the
original film format size.

>As for flatbeds used for scanning prints, I thought that there was no
>benefit in going beyond about 200ppi

Correct (I heard 300 ppi); but this is with respect to acquiring additional
sharpness, detail, etc.  It is not the case if one is talking about resizing
or rescaling of images to larger sizes without interpolation.  Thus, if you
scan a 4x5 inch print at 200 or 300 ppi and rescale or resize it to 8x10,
you will wind up with only an optical resolution of 100-150 ppi; but if you
scan it at 1200 ppi and rescale or resize it to 8x10, you will wind up with
an optical resolution of 600 ppi ( or 300-400 ppi to spare should you wish
to rescale the 4x5 to 16x20 at 200 or 300 ppi). In the case of flatbed
scanning of prints, the high optical resolutions of the scan are for
purposes of rescaling not for purposes of acquiring additional content
information or substantive data for sharpness, contrast range, or additional
detail in shadows and highlights.

-----Original Message-----
From: owner-epson-inkjet@leben.com
[mailto:owner-epson-inkjet@leben.com]On Behalf Of Bob Frost
Sent: Monday, June 03, 2002 3:39 PM
To: epson-inkjet@leben.com
Subject: Re: Resolution and Banding


Laurie,

I agree that if you are using medium- or large-format film you may have
surplus pixels. But from looking in the large refrigerators - full of
professional film at the photographic dealers that I buy film from - most of
it was 35mm. Of the photographers I know, two or three have larger format
cameras (Hasselblads or Bronicas) but they tend to remain tucked away in a
cupboard and only brought out for 'ceremonial' occasions! So I don't think
most of us have surplus pixels, unless we are printing at holiday-snap size.
Although I can see the benefits from the larger formats, my 60+ year-old
cervical vertebrae simply won't take any more weight than my F100 and AFS
80-200 zoom. I even had to buy a wider strap for that combo recently, to
reduce the pressure. So medium- or large-format might be OK for youngsters,
studio work, or those who have minions to carry their cameras around, but
not for oldies like me who have to carry their own gear, up and down dale.

As for flatbeds used for scanning prints, I thought that there was no
benefit in going beyond about 200ppi. I must confess that I haven't done any
detailed testing in this area, as it is something that I rarely do, but I
seem to remember arguments on this list where the 'winner' maintained that
his tests showed that there was no further detail to be gained from prints
above that resolution. So, if that is the case, using 1200 ppi is probably
just a waste of anybody's time and pixels.

Bob Frost.

PS I suppose I could predict that someone will now tell me that a medium- or
large-format combo weighs less than my 35mm setup. C'est la vie!

----- Original Message -----
From: "Laurie Solomon" <laurie@advancenet.net>

> Yes, but you are scanning a 35mm frame at the 4000 dpi optical and
resizing
> it around 8 times to 8x10 which gives and effective optical dpi of around
> what you suggest; however, some either are scanning larger formats at 2000
> plus optical dpi which are then resized by only 1/2 the amount you are
doing
> to get an 8x10 with an optical dpi of around 1000 plus effective dpi or
are
> scanining an 8x10 print on a flatbed at 1200 optical dpi or greater and
not
> resixing the image at all to get a 8x10 output to get an effective optical
> dpi of around 1200 plus.


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