From: mikec@spider.co.uk (Mike Coren)
Newsgroups: rec.photo
Subject: Re: Vignetting with Canon EF 28-105mm USM
Date: 5 Jan 93 15:14:37 GMT
Organization: Spider Systems Limited, Edinburgh, UK.

In article <1993Jan4.103553.2024@sequent.com> blue@sequent.com (Gil Delavous) writes:
>In article <1992Dec29.162001.8038@spider.co.uk> mikec@spider.co.uk (Mike Coren) writes:
>>
>>About a week ago someone posted something here saying he had experienced
>>vignetting at 28mm with the Canon 28-105mm USM lens.  [ ... ]
>>
>>Anyway, I have owned this lens since the end of October, and I have probably
>>shot a dozen rolls of prints with it.  I looked at my negatives, scrutinizing
>>those I thought had been taken at 28mm, and I could see no vignetting.  All
>>I can think is perhaps you were seeing the effects of either an improper
>>hood, or a large filter.  I use a Hoya UV filter over mine, and still have
>>not had any problem.
>>
>>By all counts, the lenses in Canon EF lineup are excellent, even the cheap
>>plastic Rebel/1000 lenses.  Given that the 28-105mm USM costs about 40% more
>>than the 28-80mm USM, and that Canon is selling it along with their next-to-
>>top-of-the-line EOS-A2/5, I would hesitate to suggest the lens itself has
>>such a fundamental flaw in its design.
>>
>>Mike
>>
>>-- 
>>Michael D. Coren, Electrical Engineer             mikec@spider.co.uk
>>Telecommunications Techniques Corporation, Germantown, Maryland, USA.
>>Temporarily at Spider Systems Limited, Edinburgh, Scotland, UK.
>
>I'm the guy who posted the article. You must be more than lucky with your lens
>because 2 friends of mine have the same lens and the same vignetting problem
>at 28mm without any filter or hood, and "Chasseur d'Images" also mention it. 
>However it's *not* a big vignetting, I'd say 0.5EV maximum (well it can hurt 
>with slides :)
>

Hmmm...  0.5EV isn't much, maybe I should shoot a roll of slides and see.
Is the effect obvious on the slide itself, or only when it's projected?  I
couldn't see it on any of my negatives, and most commercial labs chop off
about 2-3mm worth of negative around all four edges when printing.

>Also, if you put the Cokin filter holder, the vignetting is more than obvious at28mm (black corners).

Yes, with my Cokin A filter holder, at 28mm I can clearly see this in the
viewfinder.  The Elan/100 viewfinder only covers about 96% of the actual
frame, so for it to be visible in the viewfinder is pretty serious.  I haven't
tried it with a Cokin P holder though (Would there be any difference, or is
the limiting factor the 58mm filter ring?  I think Cokin does recommend the P
system for lenses wider than 35mm).  In the lens instructions, they do say that
you can use up to one filter without any problem, and I was putting the Cokin
holder on over my UV filter.

>
>Bottom line, I can deal with that and I still like this lens!

Good!  I also think it's an excellent lens, and again, I've had no cause to
complain.

>
>Happy? ;-)
>

Thrilled.  Oh joy. ;-)

Now, the only question I have is has anybody out there in net.land noticed
this with the 28-80mm USM (either the regular or the "L" version)?  Could
this have been a concession made when extending the range to 105mm without
changing the package size?

>Gil.

Cheers!
Mike

-- 
Michael D. Coren, Electrical Engineer             mikec@spider.co.uk
Telecommunications Techniques Corporation, Germantown, Maryland, USA.
Temporarily at Spider Systems Limited, Edinburgh, Scotland, UK.
Newsgroups: rec.photo