[Leica] Clarification of "Lens Quality . . . "

[don.dory at gmail.com (Don Dory)]

Martin,
If your aim is to determine really fine detail in an image, that has been
digital for more than a generation.  The algorythyms to increase local
contrast, decrease noise, and improve edge delineation have been used for
quite a while now.  Back to inkjets, the joy of 1400 dpi is that it shows as
continuous tone to human vision, ie invisible to the unaided eye.  If you
want to check some small part of an image, blow that part up and print it at
whatever size you desire using whatever software aids will decrease noise
and increase detail resolution, you will still not see the dots.

I think that there is a sub play of lens improvement going on.  Leica has
just brought out a whole line of lenses that upped the ante for everyone
else; the 21 through 135 ASPH's, with the 70-180 APO, the 90 ASPH, the rare
35-70ASPH, and all the modular lenses.  Zeiss has responded with a line, and
Canon has redesigned all their telephotos to include Fluorite and IS
technology.  I sense that Nikon is working on their lenses to resolve much
finer detail.  Nikon has designed around the APS-C sensor size and the one
true benefit of that is a much finer pixel pitch.  Theoretically this could
translate into the ability to resolve much finer detail.

Then there is the revolution going on in medium and large format lens
design.  Rodenstock and Schneider have designed whole lines of lenses to
match up with the new 22 and 39 MP backs.  All reports indicate stunning
ability to resolve detail with little or no flare, distortion, astigmatism
and all the other banes of optical design.

This has been one of the best twenty years ever for improved lens design,
every bit as good as the period from the thirties to the fifties.  It just
makes technique that much more important.  In the days of the Sumar, a
little misfocus and a little hand shake could be disguised by the softness
at F2, but the new 50 ASPH will show you just how far you pushed to get the
image.

Thanks for asking.

Don
don.dory@gmail.com


On 5/28/06, Martin Krieger <krieger@usc.edu> wrote:
>
> 1. The reason I might use a loupe is that I have a print and I want to
> read some detail in that print. So the question becomes how much detail is
> available before it turns into grain or dots. Surely it matters about the
> enlarger, etc, vs. merely printing a digital file, and surely it matters 
> how
> many dpi are put out by the inkjet printer (and the resolution of that
> system... If you paper resolves 25lp/mm, that is 600+ lp/inch, I am not 
> sure
> what 1400dpi means in terms of resolution).
>
> 2. As for lenses, I find it interesting about the Canon L lenses being so
> good, and it only being revealed in digital systems. If someone could lead
> me to this work I would be most grateful.
>
> 3. Still, perhaps we have reached a plateau in lens quality for the price
> most of us would pay, and technological improvements are not on the 
> horizon.
> I don't know. Does anyone have insights about this.
>
> Thank you all for your comments,
> Martin Krieger
>
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information
>