Digital BW, The Print

I've shot and examined Velvia under a microscope with both MF and 35mm
lenses, and both lenses reached the resolution limits of the film.  So while
MF lenses might not be as sharp, they still seem to be sharp enough for most
films most of the time.

----- Original Message -----
From: "Paul Roark" <paul.roark@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Wednesday, May 21, 2003 18:02
Subject: RE: [Digital BW] Digest Number 1514 -- Medium format resolution


> >...
> >Keep in mind that as you go up in format lens quality tends to go
> >down, just 'cause it's really hard to make a good lens to cover that
> >much film real estate.   ...
>
> I have tested a lot of 35mm and medium format (mf) lenses.  While it is
> certainly true that it is more expensive to make a medium format (or any
> wider-image-circle) lens with resolution equal to a good 35 mm lens, most
mf
> lenses are, indeed, more expensive.
>
> Bottom line -- most of the mf lenses I've used and tested are about "as
good
> as" the 35 mm lenses I have, which has included Canon "L" serious lenses.
> ("As good as" means to me equal central resolution, equal or better
> resolution at the 35 mm image size, but usually slightly lower resolution
at
> the edge of the mf frame -- where size of negative more than makes up the
> difference.)  The most consistent differences are that the mf lenses are
> more expensive and the 35 mm lenses have a larger maximum aperture.
>
> The major problem I've had with most mf cameras that decreases their
on-film
> performance is the lack of film flatness.  The curls that most mf backs
put
> in the film cause the film to pop off the film plane (unless you have a
> Contax with 220 film and a vacuum back).  With my Rolleis, I overcame this
> problem by shooting only every other frame, so that I never used the film
> that had been bent around a roller.  Many newer, straight-film-path mf
> cameras are now as good as the 35 mm cameras in this regard.
>
> The only lens I ever tested that would resolve 100 lp/mm, on film, at the
> center and edge of a 35 mm frame, wide open, was my 150 mm Zeiss Sonnar
that
> I adapted to my Canon (so as to make a tilting 150 telephoto).
>
> Probably the softest lens I have in terms of edge performance at f8 is the
> 45mm Canon Tilt and Shift lens (58 mm image circle with radical retrofocus
> design required by TS mechanism).  The 24 TS mm was so bad I sent it
back --
> fun lens, but just not up to display print enlargements.
>
> The Bronica RF 645 that is now my favorite landscape camera will out-shoot
> my Canon on a light tripod and within the 35 mm frame with no problem --
due
> to both outstanding optics and -- often overlooked -- virtually
> vibration-free leaf shutter.  When I go to the full frame mf, of course,
> there is no contest at all.
>
> Given the importance of vibration from focal plane shutters and film
> flatness in mf cameras, I often think the focus on lens tests is
> over-emphasized.  These other problems, if ignored, wipe out the
advantages
> of our expensive glass.
>
> Paul
> http://www.PaulRoark.com
>
>
>
>
>
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--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Anthony 
Atkielski" <anthony@a...> wrote:
> I've shot and examined Velvia under a microscope with both MF and 
35mm
> lenses, and both lenses reached the resolution limits of the film.  
So while
> MF lenses might not be as sharp, they still seem to be sharp enough 
for most
> films most of the time.

I've never shot Velvia, but I've done this with Panatomic-X (back 
when it existed) using the standard Air Force test target and The 
Nikkor 105mm f/2.5 at it's optimum aperture was sharper than any lens 
I could find for an RB67.