Extender question for Canon 20D

Hi,



I got a Canon 20D recently along with a Canon EF-S 17-85mm f/4-5.6 IS USM
lens. A Canon technician told me that the Canon Extenders EF 1.4x II and EF
2x II will not fit that lens.



I was thinking about buying one of the Canon EF lenses that will work with
the Extenders. I'm planning on using this kind of system to shoot outdoors
(drag races, sprint car races, etc.) as a spectator, seated in the bleachers
and walking about.



I have a Canon EF 70-200mm f/2.8 IS USM lens, but it's a bit heavy to lug
around so I would be willing to sacrifice on the f-stops to have a lens that's
a little more compact and lighter. Image Stabilizer and the USM auto focus
would come in handy.



Any Canon lens suggestions?



Thanks for the great help I get here!



Dave

Dave wrote:
Hi,



I got a Canon 20D recently along with a Canon EF-S 17-85mm f/4-5.6 IS USM
lens. A Canon technician told me that the Canon Extenders EF 1.4x II and EF
2x II will not fit that lens.



I was thinking about buying one of the Canon EF lenses that will work with
the Extenders. I'm planning on using this kind of system to shoot outdoors
(drag races, sprint car races, etc.) as a spectator, seated in the bleachers
and walking about.



I have a Canon EF 70-200mm f/2.8 IS USM lens, but it's a bit heavy to lug
around so I would be willing to sacrifice on the f-stops to have a lens that's
a little more compact and lighter. Image Stabilizer and the USM auto focus
would come in handy.



Any Canon lens suggestions?

How about the Canon EF 70-200mm f/4.0 USM L? No IS.

Larry wrote:
Dave wrote:

Hi,



I got a Canon 20D recently along with a Canon EF-S 17-85mm f/4-5.6 IS
USM lens. A Canon technician told me that the Canon Extenders EF 1.4x
II and EF 2x II will not fit that lens.



I was thinking about buying one of the Canon EF lenses that will work
with the Extenders. I'm planning on using this kind of system to shoot
outdoors (drag races, sprint car races, etc.) as a spectator, seated
in the bleachers and walking about.



I have a Canon EF 70-200mm f/2.8 IS USM lens, but it's a bit heavy to
lug around so I would be willing to sacrifice on the f-stops to have a
lens that's a little more compact and lighter. Image Stabilizer and
the USM auto focus would come in handy.



Any Canon lens suggestions?


How about the Canon EF 70-200mm f/4.0 USM L? No IS.

Good suggestion. I have it and it's an excellent lens.

In article ,
"Dave" wrote:

Canon EF-S 17-85mm f/4-5.6 IS USM
Canon Extenders EF 1.4x II and EF
2x II will not fit that lens.

I was thinking about buying one of the Canon EF lenses that will work with
the Extenders. I'm planning on using this kind of system to shoot outdoors
(drag races, sprint car races, etc.) as a spectator, seated in the bleachers
and walking about.

I have a Canon EF 70-200mm f/2.8 IS USM lens,
but it's a bit heavy to lug around so

OK, you've got THE BEST lens for your stated needs and you WANT to buy more
stuff and switch to some comparative KLUGE with an extender?

I have a 20D and have your very lens HIGH on my "must have" list. Some day,
perhaps... sigh

I would be willing to sacrifice on the f-stops to have a lens
that's a little more compact and lighter.

Aren't a lot of races held after dark in the sprint world? I would WANT those
stops. I'd probably NEED them except on the brightest days.

Image Stabilizer and the USM auto focus would come in handy.
Any Canon lens suggestions?

Canon EF 70-200mm f/2.8 IS USM

Oops. You already have that one. Sorry, that's the best I can think of.
--

JR

"Dave" wrote in
. com:

Hi,

I was thinking about buying one of the Canon EF lenses that will work
with the Extenders. I'm planning on using this kind of system to shoot
outdoors (drag races, sprint car races, etc.) as a spectator, seated
in the bleachers and walking about.



I have a Canon EF 70-200mm f/2.8 IS USM lens, but it's a bit heavy to
lug around so I would be willing to sacrifice on the f-stops to have a
lens that's a little more compact and lighter. Image Stabilizer and
the USM auto focus would come in handy.

Sorry, but any fairly low-light capable telezoom worth having is going to
be large, and IS adds weight.

In addition, the Extenders have a price to pay as well: aside from
degrading the image, especially in low light, they hurt autofocus pretty
badly. As in it becomes very slow and innacurate - not the best thing in
sports of any sort.

Any Canon lens suggestions?

The 100-400L IS. Better image quality than the 70-200 with a 2X Extender,
slightly lighter (IIRC), meets pretty much all of your specs, lots more
reach than you're current setup. And you only lose between 1/2 and 1 stops
of light instead of the 2 of the 2X Extender.

Eric Gill wrote:
"Dave" wrote:
Any Canon lens suggestions?

The 100-400L IS. Better image quality than the 70-200 with a 2X Extender,
slightly lighter (IIRC)...

System weight on a 20D of ~4.5lbs versus ~5.25lbs, a difference of 11
ounces or 15%, which is a question of if its worth the cost, since its
a tariff of $100 per ounce.


... And you only lose between 1/2 and 1 stops
of light instead of the 2 of the 2X Extender.

I think your math is a bit confusing or deceptive here.

His current 70-200 f/2.8 IS with a 2x would become a 140-400mm f/5.6
lens (full range), whereas the 100-400 IS is an f/4.5 - f/5.6, so from
a light-gathering perspective, they're identical at the long end...ie,
both are f/5.6

On the short end, the 100-400 is only a half stop faster (f/4.5 vs
f/5.6).

But that's only until we remember that the 2x can be removed from the
70-200, which makes it once again an f/2.8, which means its at least
1.5 stops better than the 100-400 for the 100mm-200mm range.


Overall, for a meaningful weight savings, I'd be inclined to suggest
giving up on L glass and to consider using the 70-300 IS. The new
versions are reportedly not as soft as the first generation, its the
same speed as the 100-400, and the system weight drops by ~23oz (33%),
to just under 3lbs, including the 24oz 20D body.

With the DO version of the 70-300, that's roughly $50/ounce, and for
the non-DO version (but still IS), its under $25/ounce.


-hh

In message ,
Eric Gill wrote:

In addition, the Extenders have a price to pay as well: aside from
degrading the image,

I have problems with terminology like this. To say that a quality TC
"degrades the image" is not very accurate, IMO, and can lead to false
conclusions. The Canon TCs, the Tamron SPs, and the Kenko Pro 300s do
very little of what I would call "degradation". Their job, as a TC, is
to magnify the lens' image on the analog focal plane, and they do a good
job of it. The problems come from users, who don't understand what they
are, and what they are useful for.

The first thing you have to understand is that when you put a 2x
converter on an f/5.6 400mm lens, you are now holding an f/11 800mm
lens, that may need to be stopped down to f/13 or even f/16 to be sharp
enough to warrant this magnification, and may need a doubling of shutter
speed as well, if you're already near the limits of hand-holdability.
If you give the combo what it needs, and the main lens is sharp, you may
get detail unobtainable by the lens itself, from the same distance.
Even if you don't get much more detail, you may get a better sampling of
the detail that is there, as it is spread out over 4x as many pixels,
making the digitization artifacts smaller in a same-size image of the
subject, as compared to the lens with no TC. If this does not make you
resort to under-exposure, then it can be a gain. If it forces
under-exposure, then it may not be worth it, as you will have smaller,
but stronger digitization artifacts.

especially in low light, they hurt autofocus pretty
badly. As in it becomes very slow and innacurate - not the best thing in
sports of any sort.

I turned the AF off on my telephotos over a year ago, and I don't regret
it. I don't use AF with a TC, and I don't use it without a TC, either.
The amount of time it spends lost and hunting is far more than the
amount of time it takes to twist my wrist into focus. My (technical)
keeper rate has gone up quite a bit since I learned to manual-focus.
Some of the most frustrating moments of my photographic life were AF
gone awry. Excellent opportunities wasted, because I was foolish enough
to trust AF, and it went the wrong way.

I think TCs are great tools, but you have to be realistic about when
they are useful. I generally use mine only when the ambient light is
fairly bright, or it is so dark that I am shooting with a high
flash-to-ambient ratio by necessity. I carry both a 1.4x and a 2x with
me when I am shooting wildlife, and their usage is dictated by the
lighting and the lens. I use them most often with my Canon 100-400 IS,
which I know by experience is very sharp at close range at 400mm, and
gets softer towards infinity.

TCs are not magical optical devices, but they are useful tools if you
develop the skills and judgement necessary to use or refrain from using
them.
--


John P Sheehy

The www.canonusa.com web site has a list of lenses which are compatible
with the Canon telextenders. Consult the list to be sure!

"wilt" wrote in message
oups.com...
The www.canonusa.com web site has a list of lenses which are
compatible
with the Canon telextenders. Consult the list to be sure!

But also realize that where the Canon extenders cannot be used
(usually a conflict between protruding rear lens element and front
extender lens element), the Kenko 300Pro ones may fit.

Bart

wrote in message
...
In message ,
SNIP
I think TCs are great tools, but you have to be realistic about
when they are useful.

Indeed, and besides the increased risk of camera shake due to loss of
light, there's an easy test to see if it does help at all for a given
lens. Since all it does is magnify the center portion of the lens'
projected image, one is usually safe with top quality lenses, but for
lower quality ones the test involves the following.

Shoot one well focused shot with, and one without TC. Now magnify the
shot taken without TC to match the magnification of the shot with TC.
Which one is sharper or has less CA? That's what will tell if it's
worth the increased risk of camera shake to begin with.

In addition, in general the performance of a TC is tuned towards
longer focal lengths, and there may be quality loss towards the
corners but to which degree obviously depends on the lens used and
subject chosen.

Roger Clark has published some results on his pages:
http://www.clarkvision.com/imagedeta...ess/index.html

Bart