What is the best m43 for focus tracking?

Started Mar 31, 2013 | Questions thread
amtberg
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Re: what is the best m43 for focus tracking?
In reply to Anders W, Apr 3, 2013

Anders W wrote:

amtberg wrote:

Anders W wrote:

Second, I have excluded the results for the Olympus E-PM2 and E-M5 since the results indicate that the lab made the mistake of shooting both cameras in high-speed burst mode where they won't even try to AF between shots. The buffer has then filled rapidly, which explains the slow rate at the end of the series.

Seems like you disregard the bad result for two  cameras while ignoring a related problem in this whole test.  It wasn't just the EM5 and EPM2 where bad settings/buffer size affected the results.  Many of the cameras apparently ran out of buffer before closest approach.

What would the examples be and how do you deduce that they did?

I think that is giving some of the DSLR's artificially bad results.  And in general, the results are not as fine-grained as the numbers suggest insofar as there seems to be a +/- difference of at least 3-4m depending on when the burst was started and thus when the last exposure was snapped in relation to the object distance.

Again, on what basis do you draw that conclusion? Just want to hear how you reason before saying what I think about it.

More generally, there may well be a margin of error of the kind you suggest (although I'd say it is hard to tell how big it is) which is why I suggest looking at the broader pattern and not pay too much attention to the results for each individual camera. Preferrably, they should have run this test a number of times per camera and reported the mean as well as standard deviations.

But this is about the only systematic AF-C test that I have been able to come up with and I think that, if interpreted in terms of broader patterns, it does tell us something. Let me know if you or anyone else has a better data source.

I'm just looking at their diagrams showing when the photos were taken in relation to the proximity of the approaching focus target.  In many cases, especially with the DSLRs, the buffer seems to have filled up before the target got very close, so the frequency of pics slowed down.  If the last pic in the series was snapped at 20m, that's obviously not going to be an accurate reflection of that camera's C-AF performance.  Look at the Sony A77, for example.  The buffer ran out at about 19m, then one more pic was taken at about 15'.  Could it have AFd at 5'?  Who knows?  In the case of the 5D, the closest shot attempted was at about 8.5m.  With the 600D no pics were taken inside of 11m.

In every case the closest attempt depends entirely on the timing of the burst.  So, for example, with the Nikon D800 the last pic was snapped at 4.5m and the second to last at 8m.  What if the last shot had been at 6m instead of 4.5m?  Might it have been in focus?  Maybe....

If the GX1's buffer had been started a hair later might not have taken that list pic and it could have scored an 8 instead of a 2.

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