Archived posting to the Leica Users Group, 2003/06/30

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Subject: RE: [Leica] OT: Just went MF, need scanner advice
From: "Austin Franklin" <darkroom@ix.netcom.com>
Date: Mon, 30 Jun 2003 22:31:51 -0400

Hi Gilbert,

> Well, if I open a raw scan of a 35mm negative, full frame, I see 4560 X
> 6730 pixels, which sounds an awful lot like 4800 dpi to me. I'm no
> engineer, and I don't know if pixels = sensor elements, but the pixels
> are definitely there, and I haven't instructed the software to do any
> interpolation.

Sorry, you misunderstood my comment.  I am not disputing the purported
optical resolution, but that is only one part of the equation.  There are
other factors that can very well decrease the actual usable resolution, like
smear and bloom, and the optical path...so because a scanner has a
particular hardware "resolution", that doesn't mean it actually performs up
to it.

> When you say that a claimed 3200 dpi optical might only
> be 2400 are you saying that the file has fewer pixels, or is this
> something comparable to the lines per mm by which they test lens
> resolving power, and how DO you measure that?

It's measured by scanning, typically a slide, that has variable line
widths...just like when measuring film.

> > I'd love to see some full resolution scans from it!  Are there any
> > on-line
> > comparisons of it vs the Nikon vs the Polaroid?
>
> I don't know of any, but I do see more detail than I did with either
> the Nikon 4000ED that I owned very briefly or the Polaroid I had before
> that.

I was talking compared to the MF 4k scanners, which should be better than
the 35mm brethrens.

> If in the absence of a
> scientific comparison, you still want to see a full resolution scan
> from the Minolta I'll send you one, either by ftp if you have space on
> a server or on CD if you'll email me a postal address off-list.

I may be a scientist, but I believe the proof is in the pudding, and yes, I
would really like to get a hold of some decent full resolution scans to
check them out.  We can discuss that off list.

Regards,

Austin

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