Advanced AF Frustrations: does your 7D Zone AF front focus vs other modes?

Started May 8, 2012 | Discussions thread
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katman68 Regular Member • Posts: 487
Advanced AF Frustrations: does your 7D Zone AF front focus vs other modes?

I pulled out the tripod to do some testing to confirm microadjustment on my nearly 1 1/2 yr old 7D, and discovered Zone AF mode(and sometimes Point Expansion) tends to front focus requiring about +3 - +4 microadjustment more than other modes. I'm aware of Zone mode tending to focus on the closest AF point, but being my testing consisted of shooting something on paper flat against the wall this is truly BIZARRE.

This is the basic theme with all 4 Canon EF lens combinations: 28-70/f2.8L, 70-200/f4L IS(both with/without 1.4x II extender), and 100/f2.8 Macro USM

It occurs shooting in One Shot AF at all distances tested: 5', 9', 30', and 50'. To some this might sound minor, but at closer distances/higher focal lengths it is obviously a big deal.

I utilize the 7D's multiple AF modes quite often, including switching to Zone AF for birding if there's trouble tracking. This could explain why recently I've noticed shots not being sharp as I'd like, even at shutter speeds 3X the 1/focal length

Another possible culprit is during this testing I also noticed Point Expansion mode to be somewhat inconsistent/unreliable, which might explain the same sharpness issues recently as above(I use this mode for birding often as I can). Several shots out of the blue were way off correct focus distance, yet the camera appeared to have no trouble locking nor need to use the assisting points?!

Too bad this didn't occur prior to the warranty expiration. I've loved my 7D but am starting to wonder if there is merit to some of the pros out there that put the 7D thru the ringer in very demanding venues(like sports) that said they were displeased w/the 7D's inconsistency & prefer their 1D series.

Even though I've been shooting 25 yrs, up to now when I've had that "perfect shot" slightly out of focus(despite previous microadjustment) I just brushed it off as just bad luck or technique/settings. Now, I'm not so sure!!!

Have the feeling if I had the money to trade out & get the new 5D MarkIII I'd do it & never look back! From what owners are saying, its AF is exceptional to the 7D, high ISO performance is very impressive, and even cropping frames down to 7D(1.6x) size owners claim the 5DMkIII's STILL look better even though they equal approx 8 MP. Very pricey, but sounding more & more it's a "get what you pay for" camera.

Any other advanced 7D owners with similar AF discrepancies like I'm having above, please chime in your take on this issue. Am starting to think until I can afford a better body I'll have to change my technique to burning up ALOT of memory using the 7D's 8 fps to get a sharp shot....


Canon EOS 5D Canon EOS 7D Canon EOS-1D
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