My apologies for not picking up on this excellent thread.
Sony do not have a reasonable full frame fisheye option. This pretty much renders the A7 and A9 cameras limited for underwater use.
You can use converters, but these all to some extent affect focus speed and accuracy. They also add to the bulk of the housing.
I am very wary of the claims that manufacturers use in general, but particularly with regard to AF. Whilst mirrorless AF is improving, SLR AF is too. The AF on the newest Canon and Nikon SLRs is a generational improvement on the previous versions. Given how critical AF is for underwater use, this should influence our choices significantly!
Adam
Biggest problem and the end of the discussion (as far as I am concerned)
No decent fisheye option...
I guess we should also discuss the A7RII's autofocus too!
Adam
Tut tut Adam.
I've just sorted the Metabones MkV with Tokky 10-17 for my a6500. Top side, the AFC in green mode is very encouraging, so let's see what happens when I get to Socorro in a couple of months.
JB
I'm with you. It truly is interesting and often perplexing to see how others see or think things work. For some reason, I can't help but think of RPN calculators, which folks I work with.... including my self, still use today and firmly believe there is nothing better; however, we've be hard pressed to find a Reverse Polish Notation calculator anywhere.... go figure.
Back to the topic at hand. This YouTube video put together by a professional photographer helped me a lot.
He elaborates, explains benefits and demonstrates how to program or customize specific buttons the A7R2 to essentially perform focus acquiring and locking in keeping with what the end user wants. I'm sharing it here with the group. I found it beneficial and have implemented some of the suggested tips and tricks to better control focus features.
Cheers,
Ricardo
Hey, now... don't be dissing my HP11c.... LOL!
Can't live without them. Love my 41C. Fortunately, there is an ap for that....
I've been trying the Sony 28/2 with the wide converter (21mm effective) behind Seacam's CompactPort. Not bad although corners not perfect - the Superdome would probably improve things but its too vulnerable in Scottish waters. Good vis helps though - who needs fisheyes? (Only kidding).
Pink encrusting calcareous algae in a Scottish sea loch and, would you believe, sea loch anemones (Protanthia simplex) - glacier worn rock.
