Wednesday 16 December 2009

Canon 7D AF testing

As promised on my last post, I said I would write up some of my experiences on the 7D AF system.

Now for us folks who have stuck out with Canon 1Dmk3, this is probably the one area that many of us have struggled with. It is is against this backdrop of Canon marketing spin, plus the poor ISO capabilities of the 50D that many have become doubtful of marketing speak.

As I mentioned when the same sort of hype heralded the launch of the 7D I was very cynical but said I would believe it when I was able to confirm it myself, with the type of photography that I do,  and not  have my views based on someone else's claims.

As I posted here on high ISO's Canon finally caught up with themselves on the 1Dmk3 v 7D noise issues but I did not get the chance to check the AF performance for moving subjects.

Now I have and it proves what a dog the 1Dmk3 really was/is for this type of subject.

The set up for the 7D has essentially all the same AF elements that the mark 3 has in terms of AI servo sensitivity, tracking, search, micro adjust, assist point selections.  It is more complicated with a range of different settings such as zone or area.  For my type of work, a lot of this quite unnecessary, but it might be relevant to some I guess.

The shots below were all taken as L jpegs, at 8fps, as faithful picture style, Auto WB,  in srgb for testing purposes, ISO 400, Av mode, f5.6, partial metering mode, Canon 70-200f2.8 ISL lens.

Af settings were AI servo, with the sensitivity set back 1 notch to medium slow, centre point only with surround AF assist points, focus search on, tracking priority activated.

All images are cropped to roughly half size and to 1024 x 768 pix when you click on them

Blackheaded Gulls coming for bread at Stratford -upon-Avon

One coming in from right hand side

Foreground bird (not the subject being tracked) coming across main subject, subject still sharp

Subject mostly covered but still sharp

Subject now uncovered, but still sharp and another one coming across too

Subject again interfered with by foreground bird, but subject still sharp

  Interfering birds out of subject area, subject still sharp

So having carried out my own reviews what are my thoughts?

Well it is a 1.6 crop body, so if you have a 40D this would be a good upgrade.  If you have a 50D it would be an even better upgrade, but then so would a 20D be over that.

From an AF point of view, it is very easy to use from the word go.  This was a first pick up and set up based on my experiences of the mark3 in terms of custom functions and settings.....and it worked.

I am not sure that I would ever have got 7 frames sharp in succession like this.  The AF would have wondered off  before this with the Mark3.

So to those 'experts' who said that many bird in flight wildlife photographers didn't know how to deal with the complexities of the Mark3 AF systems - your argument was just shot down by the 7D.

I do like the 1.3 crop of the 1 series though - but life is always a compromise isn't it.

So would I buy one - yes, but would need to make sure that it had the very expensive battery grip - £200!!!!  - come on Canon stop it!!!


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