Went out on lunch break to test the LA-EA3/4 adapters and 70-400 SSM2. Sunny midday light. Some findings
- Contrast detect AF mode is useless, about as slow as adapted lens AF in previous A7-models. In daytime light I could not see that it were any more accurate in static targets than Phase Detect
- LA-EA3 tracked surprisingly well, targets were moving cars doing between 80 and 100 km/h. I was in a bridge and they were coming towards me in an angle. Used flex Spot medium (gives a cluster of 9 PDAF points) + AF-C and mostly single shot shutter. Continuous slow is (the only that does tracking with LA-EA3) so slow than it felt better just to use single shot, that gives me 14 bit RAW too
- checked static targets a between 50 and 200 meters from me. AF in Phase Detect mode seemed to be about as accurate as my manual focus with 12.5x magnification+peaking, at least I could not tell difference by chimping. Was a bit surprised by this. Again it kind of "felt" flex spot medium with multiple PDAF point hitting target was more accurate
- LA-EA4 did fine too, Single shot and Continuous slow looked about same as LA-EA3 when I chimped, but using Continuous fast shutter the tracking accuracy fell dramatically. This may be caused by me losing track of target due to increased screen freeze, but regardless of the reason Continuous fast did not produce stellar results
All testing was done alternating between 300 and 400 mm, I shot maybe 300 to 400 frames. I difference in accuracy or hunting (the tracking practically never fell off target) that I could tell. Based on this I think I'll mostly use LA-EA3 in the weekend airshow (I'm still not 100% if I can make it there ). LA-EA3 gives me moving flex spot so I can leave more space in front of moving biplanes and somehow the Flex spot medium felt or even large felt more comfortable due to more PDAF points blinking than with the LA-EA4.