Daniel Flather wrote:
> >In short, vignetting in the three lenses in
> >question is close to that of Canon's
> >best lenses rather than to the worst.
>
> These are the best (or near)? My 50/1.8 at 1.8 vignettes fairly bad.
> looking a contact sheet I know what frame was shot wide open in
> bright daylight. I would hate a own a lens that vignettes on
> the "worse" side
In that case you probably wouldn't like the 50/1.0L:
f/1: 1.2 stops
f/1.4: 0.8 stop
f/2: 0.5 stop
f/2.8: 0.3 stops
f/4: negligible
The 35/1.4L tests a little worse than the 35/2 (for vignetting)
The 24/1.4L tests as follows:
f/1.4: 1 stop
f/2: 0.6 stop
f/2.8: 0.4 stop
Zoom lenses with a minimum focal length less than 50 mm tend to show the most
vignetting wide open at the short end, with typical values being 0.7 stop to 1
full stop; the longer zooms tend to show the most vignetting at the long end,
with values typically in the 0.6-0.8 - stop range. One of the best-performing
zooms (for vignetting) is the 70-200/4L:
70 mm--
f/4: 0.3 stop
f/5.6: negligible
135 mm--
f/4: 0.4 stop
f/5.6: negligible
200 mm--
f/4: 0.5 stop
f/5.6: 0.3 stop
f/8: negligible
The various 24-85 and 28-80 lenses are among the worst for vignetting, losing as
much as a full stop when wide open at the short end.
> fcc how do you find your 100/2 perform wide open?
> I find my 50/1.8 vignettes more than my 100/2
The first thing to say is that we must take account of unit-to-unit variations.
For example, although Canon says the to versions of the 28-105/3.5~4.5 are
optically identical, the Mk. II version tested by CdI did not test as well as
their example of the earlier version, in terms of resolution and distortion.
Similarly, the example of the 100/2 tested by Photodo was one of the
highest-scoring non-L EF lenses they've tested, with performance essentially
identical to that of the 85/1.8 (4.2 for the 100, 4.1 for the 85). However, in
CdI's tests, their example of the 85/1.8 scored significantly better than their
100/2. Rather than say that one or the other of these tests was flawed, I think
it more likely that the differences are due to normal manufacturing
variations--these are mass-produced items, after all.
That said, I don't see any significant vignetting in my 100/2. I must say,
however, that I've never noticed significant vignetting in any Canon lens I've
ever owned, going back to 1974. This doesn't mean it's not there; just that what
vignetting I do get doesn't affect my photos in a way that matters. Also, I
don't shoot wide on very often, at least not with shorter lenses. Perhaps it
would be more of an issue if I were doing product shots or technical
photography--but then I probably wouldn't be using 35 mm equipment anyway. Of
course, these remarks don't include vignetting due to a filter ring intruding on
the image area, like when I put a polarizer on my 20-35/3.5~4.5 without noticing
it was already wearing a warming filter. :-)
FYI, CdI's vignetting figures for the 100/2 are:
f/2: 0.6 stop
f/2.8: 0.3 stop
f/4: negligible
These figures are virtually identical to those for the 50/1.8 lenses.
Hope this helps.
BTW, CdI sells complete sets of their lens-test pages ("Fiche Technique"), in a
binder, for a very reasonable price. Included is an explanation of their test
procedures and samples of the image quality represented by their
"moyen"-"bon"-"tr�s bon"-"Excellent" rating system for MTF results. I ordered
mine through their web page, along with several magazine storage cases and a
couple back issues. Exchange rates vary, of course, but for the moment the US
dollar is fairly strong in relation to the French Franc and the Deutsche Mark
(and probably others as well), making prices attractive.
http://www.photim.net/Accueil/MenuBoutique.htm
*
****
*******
***********************************************************
* For list instructions, including unsubscribe, see:
* http://www.a1.nl/phomepag/markerink/eos_list.htm
***********************************************************
