How many 20Ds have had auto focus calibrated

"Douglas" wrote in message
news
It's odd that I bought 2, 20Ds last year and both needed to have the back
focus calibrated. One focused forward of the focus point and the other aft
of it. I thought because they had similar serial numbers they might have
been from a "made on monday" batch but recently I've come across others
who also have focus problems and the latest 20D I bought is out of focus
too.

When I took this one back to Canon, the female I gave it to with
copies of the charts showing the problem couldn't have cared less when I
told her I couldn't afford to be without this 'new' camera for the
six weeks she quoted for the adjustment. I guess I'll have to decide to
either stand douwn one photographer or buy another camera for her and use
this as a spare when it comes back. This happened at Christmas and I don't
feel like repeating the fiascoe.

It seems to me thatCanon SLRs are poorly made and even more poorly
serviced - in Australia at any rate. Anyone have any experiences to add?

Douglas

No focus problems here - sharp as hell. Infact I've had _zero_ problems with
my 20D since I bought it over 6mos ago.

"Douglas" wrote in message
news
It's odd that I bought 2, 20Ds last year and both needed to have the back
focus calibrated. One focused forward of the focus point and the other aft
of it. I thought because they had similar serial numbers they might have
been from a "made on monday" batch but recently I've come across others
who also have focus problems and the latest 20D I bought is out of focus
too.

When I took this one back to Canon, the female I gave it to with
copies of the charts showing the problem couldn't have cared less when I
told her I couldn't afford to be without this 'new' camera for the
six weeks she quoted for the adjustment. I guess I'll have to decide to
either stand douwn one photographer or buy another camera for her and use
this as a spare when it comes back. This happened at Christmas and I don't
feel like repeating the fiascoe.

It seems to me thatCanon SLRs are poorly made and even more poorly
serviced - in Australia at any rate. Anyone have any experiences to add?

Douglas

I wonder if some 20Ds have the autofocus sensor slightly higher or lower
than the target on the focussing screen, or is the vertical height of the
sensor large enough that it might focus on a line other than the one in the
vertical center of the frame? It seems that everyone who is reporting
problems with back focus is using a test chart slanted relative to the focal
plane. This would be a definate problem if the central, cross shaped sensor
is being used for the autofocus test.

It would seem like a more valid test to focus on a test target that is
parallel to the focal plane and then compare the blown-up auto and manual
focus digital images.

Dean

Dean Franks wrote:

It would seem like a more valid test to focus on a test target that is
parallel to the focal plane and then compare the blown-up auto and manual
focus digital images.

What I found to be the 'right way' (for me anyway) was a very oblique
shot towards a target lying flat. But at the intended focal point, I
placed a round metal part with the front edge right on the goal line.
For manually focussing, this was neccesary and placing the AF FP there
allowed it to AF as well. Good light is of course neccesary as well to
create the neccessary contrast.

For AF tests, the oblique is the way to go.
For focus/sharpness tests, the parallel to the film plane is the way to go.

Cheers,
Alan.




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In message ,
Alan Browne wrote:

For focus/sharpness tests, the parallel to the film plane is the way to go.

But then, you really don't know if you're focused.

Personally, I like a 5 to 10 degree angle between the target and the
focal plane, because *something* is probably going to be in focus, and
if it isn't under the camera's focus point, then you know that the
system is miscalibrated.
--


John P Sheehy

wrote:

In message ,
Alan Browne wrote:


For focus/sharpness tests, the parallel to the film plane is the way to go.


But then, you really don't know if you're focused.

Then revert to the oblique. Most appropriate for AF testing.


Personally, I like a 5 to 10 degree angle between the target and the
focal plane, because *something* is probably going to be in focus, and
if it isn't under the camera's focus point, then you know that the
system is miscalibrated.

Go really oblique with a fine line, high contrast target and you will
really see how close the AF is.

Cheers,
Alan.


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-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: Remove FreeLunch.

In article ,
(Randall Ainsworth) wrote:

*From:* Randall Ainsworth
*Date:* Fri, 29 Apr 2005 06:03:35 -0700

In article , Douglas
wrote:

It's odd that I bought 2, 20Ds last year and both needed to have the
back
focus calibrated. One focused forward of the focus point and the
other aft
of it. I thought because they had similar serial numbers they might
have
been from a "made on monday" batch but recently I've come across
others
who also have focus problems and the latest 20D I bought is out of
focus
too.

I haven't heard of any focus problems with the 20D. Maybe you're full
of ****?
That's helpful.

Do Canon Aus. have a pro service? In the UK you can have either the normal
sevicing or the Pro one where they lend you a spare camera.


Iain

Iain Laskey wrote:


That's helpful.

Do Canon Aus. have a pro service? In the UK you can have either the normal
sevicing or the Pro one where they lend you a spare camera.


Iain

Yes they do. You have to pay for it.

Douglas