DPR test samples and focus

Started Nov 13, 2010 | Discussions thread
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Richard Butler
dpreview AdminPosts: 2,145
DPR test samples and focus
Nov 13, 2010

I've read a lot over the past 24 hours about how everything we've done is wrong because our methodology, technique or ethics are somehow lacking.

I've also seen lots of blanket statements made about what we MUST do if the tests are to be fair and we're to be taken seriously.

Which is an odd position to be in as someone who's spent an awful lot of time shooting and re-shooting and re-shooting with the same camera to ensure the best possible results (And hence has spent a lot of time looking at how much difference tiny changes in focus make).

And having seen lots of side-by-side screenshots of our comparison tool that 'prove' that the shots are mis-focused, I thought I'd like to demonstrate, with examples, the counter-argument:

What's been demonstrated is that the focus between different cameras is different - that's both demonstrably true and virtually impossible to avoid, despite the large amount of time spent trying to minimise it.

What's not been proven is whether the differences in focus make a significant difference to the outcome.

So, here are three shots with focus carefully bracketed across the range being complained about. The top left box shows the focus as it appears on the site. 'New Focus' is focused towards the front of the scene and 'New Focus 2' is focused between those two extremes.

Please analyse the differences. I'm even happy to provide the original files if it comes down to it. And, once you've had a really close look, let me know which set of files you'd like included as the definitive shots (from the over 1200 shots I've taken of this target with the K-5 in the past 48 hours).

'Hang on, they all look pretty much the same' is an acceptable answer, by the way.

Richard - dpreview.com

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