Macro AF comparison Sony AR7IV vs. Olympus EM1II

[WS007]

I am owner of an Olympus EM1II and think about acquiring an additional FF system (Sony A7rIV). I would be very interested to hear about AF abilities of both cameras in macro UW photography in comparison, preferentially from people who own(ed) both camera models (or similar camera models). Normally I use C-AF&Tracking of a small spot, initially in the middel of the frame, that I track subsequently, using thumb focus, to achieve the desired framing.

Currently I use EM1II together with Zuiko 60mm and Panasonic 45mm macros, sometimes with Nauticam CMC-1 and find AF not to be great, but o.k. for my purpose.
The lenses I am considering to use with the Sony FF are Sony 90mm, Sigma 105mm and adopted Canon EF 100mm IS (I already have the Canon lens) macros, together with SMC-1 and SMC-2 (I guess I will use the closeup lenses more often with the bigger FF sensor).

The aspects I am mainly interested to compare are:
#1.: Resistance of AF against pumping, especially at longer focal lengths and close distance.
#2.: AF at low light.
#3.: How reliable the tracking works, i.e. how often is the spot lost during tracking.

Any performance that is equal or slightly better than EM1II (or other PDAF MFT camera) would do it for my purpose. In case performance is worse, I would not go for 7rIV, but wait for a newer camera with plenty of Megapixels (A1 is not considered as too expensive and 7IV does not provide enough Megapixel, in my eyes not worth the extensive investment in a new housing(better wait for rV))...

Thanks, Wolfgang

 

[hilljo88]

Not precisely the comparison you want, but I have a few observations. I shoot the SEL 90 on the A7R3 with dual YS D2 strobes. No experience with Olympus. The lens will occasionally “hunt” for focus, but is considered by reviewers to be on a par with the Canon and Nikon macro lenses for IQ. I haven’t shot Canon lenses underwater but have shot them above water with the MC11 adapter. I found the Canon IQ to be great but AF far inferior to native SONY lenses. You can probably get a good price in the second hand market for your Canon lens and get better results with the SONY. You might also have an issue in fitting an adapted lens in your housing and port.

I believe AF is worse in low light, but can be improved with a good focus light. A red light will help avoid spooking fish. Good strobes allow you to shoot at native ISO, but ambient light still an issue for focus. I think MP count is the least of your concerns. Lots of great macro shots from 12 MP sensors.