20D with a 17-40L - Lens Hood

"Stacey" wrote in message
...
Robbie wrote:

OK. I will put it on, thanks. I also put a 1a sky filter on it, to help
protect the lens.



Put the hood on, remove the sky filter..

skylight filters aren't quite the same as UV. Skylight filters have a
slight red tinge to them that a digital slr can pickup.

In article , ian lincoln
writes

"Stacey" wrote in message
...
Robbie wrote:

OK. I will put it on, thanks. I also put a 1a sky filter on it, to help
protect the lens.



Put the hood on, remove the sky filter..

skylight filters aren't quite the same as UV. Skylight filters have a
slight red tinge to them that a digital slr can pickup.

As can film; to my mind the pink tinge is rather obtrusive in most
circumstances, and is only acceptable when the scene is otherwise
excessively blue from haze.

David
--
David Littlewood

All good points on the filter. I will take it off.

"Robbie" wrote in message
news:A13hf.449$lw6.242@trnddc05...
OK. I will put it on, thanks. I also put a 1a sky filter on it, to help
protect the lens.

"Robbie" wrote in message
news:8z0hf.1064$Qs2.702@trnddc03...
I know this is an incredibly naive question, but....
I just purchased a 17-40L for my 20D. I see some folks use the lens
hood,
others don't. I have to be honest, never had a lens that came with one,
so
do not know the advantages, if any, and if the 20D 1.6 factor changes
those
advantages or disadvantages.

Thanks in advance for any insight.

"Robbie" wrote in message
news:wiihf.3481$Qs2.2904@trnddc03...
All good points on the filter. I will take it off.

Not so fast!

Depending on your shooting environment (airborne particles), a filter
will keep the dust out of the lens (it's even recommended by Canon).
Zooming towards 17mm will expose part of the inner works, and 'dust'
can be caught there. I don't think a good(!) filter will hurt your
image quality too bad, but it will do 'some' damage (I may do a couple
of tests on that, some day). Whether it is a problem for your type of
shooting, only you can determine that by shooting a comparison shot
with, and without. Good filters can be purchased under the B+W brand,
and if you use their MRC coated versions, flare will be suppressed.

In general, shoot without a filter unless it serves a purpose that
outweighs its negative side effects. Lens hoods are good impact
protectors most of the time, and they improve image quality instead of
deteriorating it like plain filters.

As far as the lens hood that comes with the lens is concerned, it was
designed for full (24x36mm) sensors/film, so it is a bit too
short/wide for use with a 1.6 FOV crop sensor. It will improve the
image contrast, but it could be better. I believe there is a hood for
another lens with the same front diameter, but I don't recall exactly
which one.

Bart

"Bart van der Wolf" wrote in message
...

"Robbie" wrote in message
news:wiihf.3481$Qs2.2904@trnddc03...
All good points on the filter. I will take it off.

Not so fast!

Depending on your shooting environment (airborne particles), a filter will
keep the dust out of the lens (it's even recommended by Canon).

Recommended by Canon to keep dust OFF of the lens, not out of it

Zooming towards 17mm will expose part of the inner works, and 'dust' can
be caught there.

A filter won't help, here. The sides of the lens barrel are exposed, the
filter fits on the front.

snip

As far as the lens hood that comes with the lens is concerned, it was
designed for full (24x36mm) sensors/film, so it is a bit too short/wide
for use with a 1.6 FOV crop sensor. It will improve the image contrast,
but it could be better. I believe there is a hood for another lens with
the same front diameter, but I don't recall exactly which one.

There may be several, but that doesn't mean they're interchangeable. The
petal shape is going to change, and that won't be designed for that lens, no
matter what the sensor size.
--
Skip Middleton
http://www.shadowcatcherimagery.com

"Skip M" wrote in message
news:Wujhf.8082$dv.4187@fed1read02...



"Bart van der Wolf" wrote in message
...

"Robbie" wrote in message
news:wiihf.3481$Qs2.2904@trnddc03...
All good points on the filter. I will take it off.

Not so fast!

Depending on your shooting environment (airborne particles), a filter
will keep the dust out of the lens (it's even recommended by Canon).

Recommended by Canon to keep dust OFF of the lens, not out of it

Zooming towards 17mm will expose part of the inner works, and 'dust' can
be caught there.

A filter won't help, here. The sides of the lens barrel are exposed, the
filter fits on the front.

snip

As far as the lens hood that comes with the lens is concerned, it was
designed for full (24x36mm) sensors/film, so it is a bit too short/wide
for use with a 1.6 FOV crop sensor. It will improve the image contrast,
but it could be better. I believe there is a hood for another lens with
the same front diameter, but I don't recall exactly which one.


Actually I just checked, and the 16-35 uses the same hood, so that's no
help...

--
Skip Middleton
http://www.shadowcatcherimagery.com

WOW.
Lots of different advice, all very much appreciated. I will take different
shots with the hood, without the hood, with the filter, without a filter,
and see what serves me best.

Thanks all!


"Robbie" wrote in message
news:8z0hf.1064$Qs2.702@trnddc03...
I know this is an incredibly naive question, but....
I just purchased a 17-40L for my 20D. I see some folks use the lens hood,
others don't. I have to be honest, never had a lens that came with one, so
do not know the advantages, if any, and if the 20D 1.6 factor changes
those
advantages or disadvantages.

Thanks in advance for any insight.

In article Jnchf.8070$dv.2907@fed1read02, Skip M
wrote:

I've found that even the best filters adversely affect image quality on
digital cameras in ways I didn't see with film. I never put a filter on one
of our lenses that doesn't serve an immediate purpose, like a polarizer or
soft filter.

Words to live by.

In message ,
David Littlewood wrote:

As can film; to my mind the pink tinge is rather obtrusive in most
circumstances, and is only acceptable when the scene is otherwise
excessively blue from haze.

If you're applying your own custom WB, a pink tinge can only improve the
image with most digitals, as it brings the exposure closer to the native
WB of the CFA/sensor combo. I shoot in ample light with a CC30M filter,
when I want maximum dynamic range. I shoot indoors with a magenta
filter over the flash. These cameras are not looking for white light!
--


John P Sheehy

David Littlewood writes:

In article , David Dyer-Bennet
writes
"ian lincoln" writes:

"Robbie" wrote in message
news:8z0hf.1064$Qs2.702@trnddc03...
I know this is an incredibly naive question, but....
I just purchased a 17-40L for my 20D. I see some folks use the lens hood,
others don't. I have to be honest, never had a lens that came with one, so
do not know the advantages, if any, and if the 20D 1.6 factor changes
those
advantages or disadvantages.

Thanks in advance for any insight.

Helps reduce flare when shooting towards a lightsource but not directly at
one. If the light is from behind you are fine.

And a lens hood for a full-frame zoom lens is unlikely to do much good
on a 1.6x camera; certainly not anywhere except the long end of the
zoom range.

I would expect it to perform in pretty well* the same way on either
camera. The most insidious effect of flare is a lowering of contrast
across the entire frame. An ultra-bright light source beyond the
angular limit of film or a FF sensor will cause just the same amount
of this contrast loss on any sensor, and be mitigated to the same
extent on either.

And, of course, the huge benefits of lens protection apply universally.

FWIW, I always use the Canon hoods on my lenses - all EF, no EF-S - on
my 10D.

*There may be occasions when a bright flare patch at the edge of a
35mm image may not be present on an APS-C sized image, which is why I
added the qualification.

Hmmm. I'm thinking in terms of a fixed lens hood being a poor
approximation of a compendium shade properly adjusted, the way the
movie people do it -- masking out everything that isn't going to end
up on the film. Seems to me the further away from the edges of the
frame the shade is, the more opportunity for avoidable flare there
will be.
--
David Dyer-Bennet, , http://www.dd-b.net/dd-b/
RKBA: http://noguns-nomoney.com/ http://www.dd-b.net/carry/
Pics: http://dd-b.lighthunters.net/ http://www.dd-b.net/dd-b/SnapshotAlbum/
Dragaera/Steven Brust: http://dragaera.info/