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11/17/2007 02:35:17 AM · #1 |
With my 10D and 70-200 4L IS, I experience back-focus by 1/2 to 1 inch using One-Shot center-point focus (F4 200mm at 5 foot focus range).
However, when I put it in AI Servo, and move the camera around the focus point in a 1 to 2 inch circle, and then settle on the focus point, the focus is very good. It takes a bit of time, and you do not get the reassuring "beep" in AI Servo mode, but it seems to improve the focus accuracy. |
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11/16/2007 03:58:39 PM · #2 |
far distance backfocus after first "calibration".The only active focus point was the far right:
//img257.imageshack.us/img257/6589/backfocuslargadistanciasq7.jpg
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11/16/2007 03:51:50 PM · #3 |
| The same result with 3 different cameras,at far distances use to focus right , sometimes fail |
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11/16/2007 03:45:56 PM · #4 |
Can you post thumbnails not full size images?
Did you do any tests with the test pattern tilted away from the lens? Looks like the lens focus is dead on in manual and that you've got AF issues.
Message edited by author 2007-11-16 15:46:37. |
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11/16/2007 03:35:09 PM · #5 |
near the left edge , all lenses f:5.6
//img220.imageshack.us/img220/4066/4esquinasoa4.jpg
Manual focus vs autofocus at f:5.6 both the same lens 70-200 IS F:4
//img266.imageshack.us/img266/3867/enfoquemnualafhz3.jpg
Message edited by karmat - see previous posts. |
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11/16/2007 03:32:18 PM · #6 |
after 2º calibration center image , all lenses at f:5.6
//img339.imageshack.us/img339/7891/4centropr6.jpg
Message edited by karmat - keep the longest side under 500 pixels, please. |
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11/16/2007 03:14:41 PM · #7 |
Originally posted by colacao:
I ´ve checked six 70-200 F.4 , IS lenses with 3 different cameras:the same problem :backfocus ,more noticiable at short distances.The last one was sent to Canon twice for calibration with the same bad results.I ´ve no answer at all from Canon about this problem
Here at F.5.6 both v.s. 18-55 kit lens after calibration
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I'm sure you are using a tripod for these, aren't you ?
A better backfocus test is to have something angled away from the lens, so you can see where it has actually focused- if at all.
Message edited by author 2007-11-16 15:14:59.
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11/16/2007 03:14:06 PM · #8 |
| yes:tripod ,cable release , I:S off |
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11/16/2007 02:54:23 PM · #9 |
| Interesting backfocus test. Flat image parallel to the lens. |
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11/16/2007 01:17:59 PM · #10 |
I ´ve checked six 70-200 F.4 , IS lenses with 3 different cameras:the same problem :backfocus ,more noticiable at short distances.The last one was sent to Canon twice for calibration with the same bad results.I ´ve no answer at all from Canon about this problem
Here at F.5.6 both v.s. 18-55 kit lens after calibration
//img453.imageshack.us/img453/7095/prueba70200xx2.jpg
Message edited by karmat - keep the longest side under 500 pixels in the forums, please. |
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08/10/2007 10:20:39 AM · #11 |
Originally posted by silverfoxx:
oh, thank you!
i thought it's only the photographer's fault
i always focus on my backgrounds, not on me
is it a lens problem or my fault? |
Do you do that intentionally? Meaning, do you (for example) aim the focus point at the background and then recompose? If so, then it's your fault, haha. If you focus on your eyes (with shallow DOF), and your hair is in focus then it's a lens issue. You can google "focus test" and print out the page it gives. That will tell you if your lens is missing focus at all.
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08/10/2007 10:16:53 AM · #12 |
oh, thank you!
i thought it's only the photographer's fault
i always focus on my backgrounds, not on me
is it a lens problem or my fault? |
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08/10/2007 10:03:33 AM · #13 |
Originally posted by silverfoxx:
could you please tell me what backfocusing is?
and recalibration? |
Back focusing is where the lens focuses behind the intended target. Front focusing is the opposite. Recalibration sets the lens to focus on the intended target instead of in front of or behind.
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08/10/2007 08:25:47 AM · #14 |
i've been taking some tennis photos today, and all of them are out of focus.
i'm very tempted to blame my camera, but i just have to admit i've never done sports shots before..
:)
could you please tell me what backfocusing is?
and recalibration?
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08/10/2007 08:08:51 AM · #15 |
Originally posted by basssman7:
This is why you should have stayed with Nikon! Canon service sucks. |
Canon service doesn`t suck. They fixed my canon 350d for free even after the warrenty expired.
However it shouldn`t have broke so easily and kept giving me errors in the 1st place :)
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08/10/2007 05:08:08 AM · #16 |
Espencor, this thread is several months old. We gave up on buying this lens in the end.
Bassaman. Really not the place for yet another sad Canon/ Nikon debate.
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08/10/2007 05:03:37 AM · #17 |
| This is why you should have stayed with Nikon! Canon service sucks. |
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08/10/2007 03:51:01 AM · #18 |
| Send your CAMERA in for sure! I have an EOS 30-D and had to send it in because of back focusing problems. Hardcore. It came back a little better but still suffers. Gonna have to send it back again. This is not uncommon. |
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10/11/2006 05:52:45 PM · #19 |
Definitely need autofocus as one of the primary types of photography we enjoy is wildlife photography, some of which is pretty quickfire stuff and also street/ travel photography handheld.
Not against a prime per se but it wouldn't be as useful for us as a zoom simply because one often has to take the shot there and then without being able to reposition oneself closer or further and a zoom allows one to fully compose the shot as one prefers in that scenario.
If we do go for a prime we'd be looking for a long one, so 200 or 300mm focal length.
Weight is absolutely crucial though...
THANKS
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10/11/2006 05:27:31 PM · #20 |
Originally posted by MadMan2k:
And, if you don't mind manual focus, setting the aperture on the lens, and having to use an adapter, you can get some very good Zeiss/Contax lenses used that will probably be just as good as the L-series primes. |
Hehe - if I didn't mind manual focusing I'd have kept the f4 - it's a stunning lens when it's actually in focus :-) |
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10/11/2006 05:23:56 PM · #21 |
Ah, fair enough.
Do you mind prime lenses? If not, have you looked at the Canon 100mm 2.0 and 135mm 2.0L? Or even the 200mm 2.8? They'll be lighter than the big zoom telephoto, and probably about equal image wise.
And, if you don't mind manual focus, setting the aperture on the lens, and having to use an adapter, you can get some very good Zeiss/Contax lenses used that will probably be just as good as the L-series primes.
Like this one. |
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10/11/2006 04:40:03 PM · #22 |
Hi Madman,
As above, it's way too heavy. I have back, shoulder and hip problems and I just can't manage heavy lenses... to some it's not that heavy but for me it's much too much.
Hence needing something of similar size/ weight to the f4 one.
:D
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10/11/2006 04:31:00 PM · #23 |
Tried the 70-200 2.8?
Considering all the time you've spent trying to get a good one, I'd assume you're pretty fond of that focal length, and a little extra bulk and weight are definitely worth the extra stop. And they might have better QC on them. |
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10/11/2006 04:24:32 PM · #24 |
Given the half hour journey from us to the store each way plus the time spent at the store too and given that we've now made about 6 trips there so far I think I HAVE been pretty patient already!
:o)
Thanks for the link!
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10/11/2006 04:36:38 AM · #25 |
The 70-300 DO reviewed in comparison to the non-DO
Maybe keep trying... Patience is a virtue and sometimes you get lucky and it is rewarded. |
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