Mike, I make your words mine. I've tried to re-adjust the screen dozens
of times (literally) but there is just no more room for adjustment. I
then chipped the edges of the screen a bit. It is possible to align it
this way, but then the screen will easily come out off alignment again
during use, because there is too much room available for the screen to
move around.
I know this has been discussed before. It is in the list archives.
However, it seems nobody has reach a definite conclusion at the time.
This is the reason why I asked it again. I was hoping that in the
meantime someone had figured out what was going on. I'll take my camera
back to Canon today and see what they can do. If there is any real
answer to this, I'll let the group know.
Thank you all for the advise.
Hugo Lopes
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Dear Hugo,
Please stop trying to align your Eos 3's focusing screen with the focusing
points. If after you've tried shifting your screen and the AF points remain
off centered, there's little you can do because it's not the screen that's
out of alignment but the illuminated AF points which are not accurately
projected onto the screen.
How do I know? Because I have used three Eos 3's and four Eos 1Vs and
currently own two Eos 1Vs and I must say that it is the norm rather than the
exception to find the illuminated AF rectangles off centered.
In all the above cameras I have used or owned, I found only ONE Eos 3 and
TWO Eos 1Vs which had perfectly centered focusing points. The others were
either slightly off to the left, right or up or down within the ellipse.
Most users probably won't notice the decentering. With the default screens,
it takes careful examination to notice decentering. However, I have an EC-D
grid screen, and upon installation, it's very apparent if the AF indicators
are perfectly aligned or not. My opinion is that it's not that the screens
are misaligned, rather, it's the illuminated AF rectangles which are not
accurately projected onto the screen.
What's the cause? I can think of two possible reasons.
Firstly, it could be that Canon's quality control (rather the lack of it)
could be at fault, resulting in the AF sensor indicators LED superimposition
system not beaming down the illuminated red AF boxes in perfect alignment
as they should be. Thus it may seem that the focusing screen is off centered
when the real problem is that the LED beamers are out of alignment.
Secondly, it could be that this "misalignment" is done on purpose. Due to
their unique fabrication process, each individual sensor on the 45 CMOS
module may not be perfectly and consistently aligned or spaced. Tiny
variations (but still within tolerances) between CMOS modules would mean
that you will never get all 45 sensors perfectly situated where they should
be.
As such, to ensure that users are aligning the subjects accurately with the
AF sensors, the LED beamers are adjusted to be aligned with the actual (off
centered) position of the AF sensors. Thus, if your AF points are projected
slightly off centered, it could simply mean that's where the actual AF
sensor is located.
I know it's disconcerting to note that the AF rectangles are off centered -
especially when using the EC-D grid screen. However, there's a small
consolation. I have found through meticulous tests of cameras with
decentered AF points that the actual AF sensors are always located
accurately within the tiny illuminated AF rectangles. That's important, cos
even though the illuminated rectangles are not perfectly centered, they
accurately indicate where the actual AF sensors are.
In conclusion, you have two choices - live with these production variations
or return your camera and embark on a holy grail to locate a perfectly
aligned unit. IMHO, the off centered points pose no problems in use although
they could be rather distracting.
I strongly urge you NOT to chip off the edges of your focusing screen
anymore. As I said, I don't think it has anything much to do with the
screen's alignment but rather the accuracy of the projected red LED
rectangles. The focusing screen is precision made to fit into its frame.
Should it start moving around as a result of your chipping its edges, your
manual focusing accuracy could be affected. AF accuracy won't be affected
since the AF sensors are located beneath the primary mirror. If your
focusing screen is very loose, it's easy for dust to get through the grooves
and coat the silvered surfaces of the camera's pentaprism.
One of my 1Vs has perfectly aligned AF sensors, while the other has slightly
off (shifted up) AF points. I've learnt to live with them.
My hunch is that if you do a survey here, you'll find that quite a number of
Eos 1Vs and 3s do not have perfectly aligned illuminated AF rectangles.
Cheers,
Jonathan Kwok
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