Hi Dawid, Moose and all,
Dawid Loubser wrote:
> .... Specifically, I am talking about my scratched, slightly busted 65mm
C-series wide angle lens, with an
> equivalent of 32mm FOV.
>
> Have a look at this recently scanned slide (Provia 100, Epson V700) shot
wide open (notice very shallow DOF,
> blurred foreground just to prove it's taken wide open :-) in very
demanding lighting conditions. This is a
> torture-test for any lens, with extremely bright highlights all over the
frame.
>
><
http://www.deviantart.com/download/141023473/Cubana_Full_Size_by_philosomatographer.jpg
>
From: Moose <olymoose@xxxxxxxxx>
>As image, separate from source, I rather like it.
So think I. However, I can see diffraction spikes at the brightest spots,
most likely caused by the diaphragm blades, thus not really wide open? The
DOF is relatively wide, having into account it's a medium format pic!
...but I may be wrong: it could be an artifact from the central shutter
(which is constructed very much like an aperture iris), or maybe the 65mm is
one of those lenses that do have a larger maximum aperture for viewing, and
will always stop down a bit until their maximum shooting aperture -- some
Zuikos do this, like the Macro 135/4.5 and... surprise! the old 35-70/3.6
(actually a 2.8-3.6 according to my testing)
>I have no dog in this fight,as I have never owned a Mamiya lens or body,
I had an RB67 setup including the 65mm lens (together with the 50, a 90 with
sluggish shutter, 127 and 180) but sold everything a few weeks ago -- I had
used it very little, it's too heavy! The Pentacon-Six would fulfill my
120-format needs ;-)
>The
>characteristic that immediately catches my attention is flare, and lots
>of it.
<snip>
>What I do see it bright light spilling over into dark spaces all over
>the place. Flare is when light that should be in one place as a
>consequence of the refractive process that creates the images, including
>its refractive aberrations, ends up in another due to scattering and
>internal reflections in the optics.
Well, a lens could be exceptionally well corrected from all aberrations and
still suffer from flare in certain conditions.
>I can't, of course say what effects in the image are due to film vs.
>processing, scanning and post processing. However, given its
>presentation as an example of lens quality, I assume it's all lens.
There are a lot of sources for flare, no only internal reflections in the
taking lens. In fact, the scanner does have some optics which may be (and
usually are, e.g. CoolScan 4000ED) causing flare _and_ aberrations.
>- The backlit "Ocean Buffet" sign on the right is almost unreadable.Faded
or
>flare? I don't know, but there is certainly flare evident in
>the left one, too.
Film may have some issues near overexposed zones, too. The left one shows a
remarkable contrast, though.
>- Look at the circular line of fluorescent light on the next windows
>down. Wherever it crosses the frames and closed umbrellas, it
>significantly cuts into the vertical lines.
Could be from the taking lens, the scanner lens or, most likely, film
halation.
>- They also are strongly affected further to the left, where the
thirdbright oval >sign and a spotlight and what appears to be a reflection
of
>it flare enough to completely obscure them.
Way too overexposed to judge the lens, IMHO.
>- The spotlights and chandeliers in the lower inside level are all blobs
>larger than the actual size.
Ditto.
>- In any case, at the size presented, the scan is at about 1000 lines
>per inch, not high enough to distinguish between even moderately good
>lenses. There's no info here about how much resolving power the lens has.
Agreed. To me, the main advantages or MF are:
-Less grain
-Less sensitive to lens' resolution -- not that much needed.
I have pics taken on Tech Pan with a Lubitel (a _very_ cheap Russian TLR
with a toy-like triplet lens) that enlarged to 12x16" look as good (if not
better) than those taken with a top-quality 35mm camera-lens.
>Now on to some issues about what makes a lens good. You prefer to shoot
>wide open for shallow DOF. That means is that you will almost never see
>image corners in focus, so corner sharpness isn't of much concern to
>you. Many photographers of landscapes and such subjects want lots of DOF
>and sharp corners.
Not necessarily antagonistic. If the lens is _really_ well corrected _and_
the subject is reasonably flat*, you may combine a shallow DOF with sharp
corners -- never as sharp as the centre, but to some extent that's also the
case when stopped down. Some aberrations simply don't increase at the widest
apertures.
*) Or shaped as required by the lens' field curvature ;^)
>Photographers of architecture want all that plus
>minimal linear distortion.
Not my case. Distortion won't affect the sharp definition of the picture.
>I can't tell anywhere near for sure, but I
>suspect from the sample that this lens has some classic bulgy center WA
>distortion.
Most likely. This is a retrofocus design -- a "very" retrofocus one, I dare
to say. But as you said, distortion isn't an issue for everyone.
>Show us some tree branch detail against bright sky in a corner of
>a frame if you want to sell that point.
But not _too_ bright, don't let other issues confuse us...
>> ... M.Zuiko 17mm, [stinks] ...
Yes, it does ;^) IME, the 35/2 offerings from Oly and Nikon are very poor
performers wide open; the older non-radiactive Canon SSC was nearly as bad,
but things got _much_ better with the newer, surprisingly lightweight and
compact FDn version. Haven't tried the EOS/EF type, I don't know if it
shares the optics with the FDn.
>> This may be ballsy, but I'd like to see if the Leica M Summicron 35mm (a
non-retrofocus design) can compare,
Non-retrofocus wide-angles do have a _big_ advantage. I'm _really_ happy
with my Cosina-Voigtlander wides (and lenses in general) in LTM and
M-bayonet mount.
>> ... Every time I lust after that OM Zuiko 35mm f/2.0 lens
I hated mine, and it was my only Zuiko for many years :-(
Cheers,
--
Carlos J. Santisteban Salinas
IES Turaniana (Roquetas de Mar, Almeria)
<http://cjss.sytes.net/>
--
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