Hi,
I guess manufacturing differences must play in to the equation. My
100/2 is a great lens. I actually have two 50/1.8mrk1's. I should see
if there is a difference in them. The second one I just picked up and
have not even used it. You know what is funny???? My ef15/2.8 vignettes
very little. Go figure, but I'm no "glass scientist" :-0
-Dan
F. Craig Callahan wrote:
>
> 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
>
>
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