2 x A65 + 4 x A57, all back focusing !

Started Jun 4, 2012 | Discussions thread
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123Mike
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2 x A65 + 4 x A57, all back focusing !
Jun 4, 2012

My first Alpha was an A33. I thought it was ok, until I bought a used Minolta 28-135 lens. I immediately saw really soft results unless stopped down a lot - and even then, it wasn't great. This was supposed to be the grand master overlord of lenses.

I then came across a blog on the internet on how to adjust the AF sensor. Two small panels can be removed near the popup flash. Revealed are 3 screws that you can change using an allen key.

Took me a few weeks to work out a good procedure, but eventually I adjusted it, at which point it became absolutely tack razor sharp on all my lenses. Notable lenses were: Min 50mm/1.7, Min 28-135, Sony 55-200, Min 28-105 Xi, Min 75-300 (II), Min big beer can 75-300, plus the cheapo 18-55 kit lens as well.

I then got excited with the newer cameras offering 60 fps for video, plus offering other improvements. So I sold my A33, and bought an A57. I tested it a little, I did notice a small amount of back-focus, but I thought that down the line I'd just adjust it like I did on the A33.

I got tempted by the prospect of having 24mp. Couldn't care less about the EVF (never use it), or GPS btw.

Disappointed. Grainy starting at ISO 100. Down-sampling fixes it unless going up to 800+ ISO. Video ISO only up to 1600. No digital zoom in video.

But the big deal-breaker: back-focus, again. Quite a bit, too, enough to spoil most photos.
I returned it, and tried another A65 in the store. Also back-focus.
Tried demo version of A57. Also back-focus.

Asked to get the previous A57 back that I returned earlier. Took that back home, examined it more carefully, back-focus.

Went to a different store. Another A57, a small amount of back focus. Yet another A57, I thought it was ok, and certainly the best so far, so took that home.

Back focusing again. On 4 lenses at least (have not tried all lenses yet), but the problem is consistent. Images of heads show soft at the front for lenses that have a somewhat shallow DOF (ie. not the kit lens).

So, that's an A33, 2 A65s, and 4 A57s, all back focusing enough to spoil things on anything better than kit lenses.

I'm attaching a few test pictures. The battery tests are done in store. The door knob at home. I'm planning on selecting a few head-shots to show how/why it's spoiling so much.

 123Mike's gear list:123Mike's gear list
Sony SLT-A57 A3000 Sony E 18-55mm F3.5-5.6 OSS Sony DT 18-55mm F3.5-5.6 SAM Sony DT 55-300mm F4.5-5.6 SAM +11 more
Sony SLT-A33 Sony SLT-A57 Sony SLT-A65
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