20D, 17-85IS Lens, Dark Corners Of Photo

Anyone else found corners of their photos are dark (Vignetting) when using a
Canon 20D and 17-85IS lens, at 17mm, in relatively low light, with high
aperture?

 

BTW, I had a lens hood on. Which was a genuine Canon lens hood for the
lens.

 

Why not try some test with the lens hood off. It is a round lens hood
or is it rectangular? If the later is it possible to put it on different
ways?

 

Does it happen with the hood off?

 

That lens, does not do that camera, justice. I think Canon created that
lens, so first time buyers of the 20D, could afford a complete camera. If
you wanted to buy the 20D, with a Canon "L" series lens, you would possibly
begin to think it's out of your price range.

Bill Crocker

 

Make sure you have it mounted correctly, it can be misaligned easily. I had
this problem on my 28-135 on a film body, once.

 

Although I am not familiar with that particular lens I always figured
your statement to be true. However, since it was designed with that
body in mind it should not vignet.

 

Thats not accurate. I have a 20D with that lens (17-85) and I do not see
this issue (I have taken enough photographs in that condition to know). It
must be the hood.

I also recently read a post of user who had both the EF-S 17-85 and EF 17-40
f/4L and he felt that the 17-85 took just as good images. Oh, by the way,
the L series is about $650, and is in no way out of the range of the 20D
buyer. Besides the 17-85, I also own a 70-200mm f/4L. When buying a $1500
body, and L-series lens is not exactly "out-of-range" by any means.

 

I will do some tests with the hood off when I get a chance. Strange for a
genuine hood to cause vignetting though.

As for the other debate, 'L' series 'V' EF/EF-S, it does depend on money.
'L' lenses are well known for their excellence, but if I bought the 20D with
'L' lenses, as opposed to EF/ES-S lenses, it would have been out of my price
range.

When I bought the 20D, I transferred from Minolta 35mm, so there was a big
outlay of money for a complete useable kit, as Bill mentioned. 'L' series
lenses will have to come in the future, but at the moment, the EF/EF-S
lenses will do me fine.

 

Do you mean _black_ corners or _darker_ corners? Most 35mm wide angle lenses
have darker corners wide open and have to be stopped down to get even
illumination across the field.

David J. Littleboy
Tokyo, Japan

 

I think you're confusing two different things.
"EF/EF-S" is a mount specification.
"L" lenses is a quality thing.
The two are not comparable.
There are many "L" EF lenses.

 

The lens test following cites vignetting at both wide and long focal
lengths with wide open f stops.

http://www.photozone.de/bindex2.html

 

The reason I mentioned the 17-40mm f/4L (L-series) is because it costs a
little more than the 17-85mm EF-S. The L is $678 and the 17-85 is $590
(www.17photo.com). Its only once you go to f/2.8L glass where things start
getting more expensive (and/or IS). Buying a $1500 body followed by a $680
lens is hardly out of reach, unless someone spent all their money on the
body, which would not make sense. BTW, the 70-200mm f/4L is under $600. If
you look at 35mm SLR photographers, they will by a $1500 body and shell out
$1500-$3000 on a lens without a blink. Really the body is a minor cost
compared to the amount you will spend on glass and lighting.

"L" is really a quality measure, whereas EF/EF-S is a mounting standard. The
L-series lenses I mention above are EF mount. Advantage of EF-S mount is
wider angles, size and weight making use of the DSLR sensor and geometry. I
expect L-level EF-S lenses in the near future. The reason is that it will be
cheaper to offer L quality on EF-S mount as opposed to EF.

 

So, what was the result with hood off??

I took almost 100 shots this weekend and I dont see the vignetting with the
17-85mm IS EF-S (even at wide open).

 

I use the 17-85 lens as a general purpose lite weight well balanced lens
on the 20D and am pleased with its performance. I haven't encountered
vignetting but I don't use the appropriate Canon lens shade. There are
times when I will purposely vignette photos using Photoshop (generally
B&W photos for affect). I also envision potential cropping of a photo
that I intend to print in various sizes and make necessary allowances at
the time I take a particular photo or series of photos.

I use a lens shade that was made for the Tokina ATX 28-135 lens. This
lens shade has a tightening screw on the side and I place the shade on
the filter thats being used. It will also fit on the lens itself but not
as securely as when fitted to a filter, though it has never come loose
when placed on the lens without a filter.

Reason I like using the Tokina shade instead of the regular Canon shade
is I can easily turn polarized filters and similar type filters and not
find using a shade with such type filters to be a nusence.

Anyway, aside from my personal practices, I haven't encountered anything
unsatisfactory when using the 17-85 lens.


nick

 

When the poster first mentioned this, I knew he meant using the hood.
I've done a lot of shooting with my 20D but just recently got the hood
for the 17-85 IS lens, and immediately noticed this issue. So I also
immediately learned to remove the hood when I zoom out to the 17-20
range.

Yes, this is Canon's hood designed exclusively for use with this lens.
Very disappointing. And very expensive at ~$35 USD.

Cheers!
-bob

 

SNIP

The OP also mentioned shooting at low light with "high aperture". I'm
not sure what he meant with "high aperture", but if he meant
large/wide-open aperture (given the low light), then most lenses will
show more vignetting/fall-off, especially with wide angle lenses. That
is mostly caused by plain physics, but can be improved by closing down
the aperture. If the situation improves by closing down the aperture,
then it is less likely that the hood is causing it. If fall-off is
practically eliminated by closing down the aperture, then the hood
doesn't play a role.

Bart

 

Joseph Meehan

Joseph, explain to me the Irish math please