How is everyone doing their AF Micro Adjustment?

Started Feb 25, 2012 | Discussions thread
Prognathous
Veteran MemberPosts: 8,652
Like?
Got mine too. It helped me realize how much I want CDAF.
In reply to reflected_light, Mar 8, 2012

reflected_light wrote:

This simple pyramid shaped focus adjustment tool is just what I was looking for. Straightforward and precise, it allows for VERY accurate adjustment of auto focus per lens with the a77.

Highly recommended, especially if you like to tweak.

I agree, it's simple and effective. Printing one of the focus adjustment diagrams available on the web and gluing it to the side of a box would probably be just as effective, but for $10 (+shipment) I think the Focus Pyramid is easier to use, and its portability is an advantage as I plan to re-adjust some of my lenses outdoors in daylight.

My first attempt was under tungsten light. Here are my results:

  • Minolta 50/1.7 (-5)

  • Sigma 20/1.8 (-8)

  • Tamron 17-50/2.8 (-10 at 17mm, -8 at 30mm, -6 at 50m)

  • Sigma 90/2.8 macro (-3 at 0.4-0.7m focus distance, -9 at longer distances)

  • Sigma 50/2.8 macro (-4 at 0.4-0.5m focus distance, -10 at longer distances)

  • Sigma 28-105/2.8-4.0 (+4 at 28mm, +2 at 50mm, +1 at 105mm)

  • Tokina 100-300/4.0 (-1 at 100mm, -2 at 200mm, -2 at 250mm/4, +4 at 300mm/4, 0 at 250mm/5.6 and 300/5.6, switching to negative focus shift when closing down to f/8.0. I didn't bother to try and correct this)

It's clear that PDAF as used by DSLR's and SLT's (like the A77) can have BF/FF issues due to many reasons - light source (color temperature), focus distance, focal length and aperture. In short, it's currently impossible to fully correct. I really wish the A77 had CDAF like that available in Pentax and Nikon cameras. Their implementation is fast enough for general use, it doesn't suffer from FF/BF and it works with all lenses (unlike the A580 CDAF which for some reason doesn't work with screwdriven lenses).

Prog.
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