21 minutes ago, SharkB8 said:
Hi Chris,
thank you so much for your insight. I do some reef work but my primary joy is shorting big pelagics in blue water. With my current setup, I’ve found that when you are likely to have close animal encounter (eg sea lions or makos/blues) the fisheye is excellent, but many other circumstances I prefer the flexibility of the zoom. I’ve found that some pelagics Truely benefit from zoom (although I would prefer them as close as possible). My issue with my current M4/3 setup (apart from the obvious issues with GH5 autofocus) is the resolution for large blow ups (which are the primary shots that I sell)
keri
How large do you want to print? With proper treatment you don't really need that many MP - 20 MP prints natively at 44 x 33cm at 300 dpi and you can go as low as 150 dpi with proper treatment of the right image. By proper treatment I mean good processing and profiling of a good clean shot, probably at min ISO and printed on a top end inkjet by a fine art printing service. See this link for some details: https://www.duford.com/2016/04/megapixels-vs-print-sizes/ Don't try this with big chain bulk printing outfits.
It will no doubt be easier and you'll have cropping space as well if you are selling a lot of truly big prints to be using a larger sensor camera of course.
It sounds like given your interest in pelagics it's a choice between a 16-35 class lens the or a WACP with a 28-70 or 28-80 lens. All the specs talk in terms of diagonal field of view and due to the barrel distortion of the WACP it stretches more in the corners than horizontally so I prefer to look at the horizontal field of view to compare Wet optics of this type with rectilinears for reach. You generally frame such subjects roughly across the frame not along the diagonal. In general I'd suggest looking at the 16-35 f4 - the 2.8 lens brings little benefit UW where you are stopping down for the corners as a rule.
So a 16-35 will give 96-54° across the horizontal frame a 28-70 in WACP about 122-75° or 122-68° for a 28-80 lens. Which shows the 16-35 will have a little more reach, in rectilinear terms the 28-80 becomes 10-28 lens when looking at the horizontal field of view.
The 16-35 used for pelagics, you could relax the criteria a little as sharp corners are not so important, so shoot a little wider aperture or even perhaps try out a smaller dome, though it could be a costly experiment, I'm not sure I'd chance using the 180mm dome even though it is listed as an option.