mirrorless suggestions

[Hoag]

Prime also often means "standard focal length," i.e. the lens is about the diagonal of the frame, so 50mm for standard 35mm equivalent. 50mm is too long u/w; 28 is better, 17 or 24 even better.

Actually, when dealing with lenses, a prime lens simply means that it is a lens with a fixed focal length as opposed to a zoom. When I do landscape or astrophotography, I will use a wide, fast prime such as a 14mm f/1.8. I know people who shoot birds in flight or aviation who use a telephoto prime such as a 400mm f/2.8 or even a 600mm f/4. (By that time, the lens costs almost as much as a good used car, but that is a different issue.) Whether it is a 14mm f/1.8 or a 600mm f/4, both are prime lenses.

The term "prime" has nothing to do with a specific focal length, only that the lens has a fixed focal length.

 

[hilljo88]

I shoot Sony A7R3 in Sea and Sea housing. This configuration is out of your budget range, and may be overkill for your application. Do you need interchangeable lens camera? If not, there are several good choices with fixed lens. Does it have to be high resolution? 10 years ago, 12 mpix cameras were giving great detail. Mirrorless may be the future but there are few if any advantages in underwater shooting where you are dealing with current, surge, buoyancy, etc, within a large housing.

 

[Rick Brant]

To answer a few questions, the depth will be shallower than 60'. Most of the reef is at 30-50' and the camera operator will be 10' or so above the reef when shooting. The shooting is like a lawnmower search pattern, with photo overlap between each line of photos. The cameras will be taking shots every second or so.

Regarding the prime lens, there are two thngs driving that choice. One is that I want no chance for error during collection of the images. We'll be somewhat remote and it is expensive to get there, so the data needs to be good. The two cameras are not redundant, they each will be canted slightly to shoot left-ish and right-ish. They need to be on the exact same focal length. The other reason for wanting replaceable lenses, specifically primes, is that sometimes there will be a need to shoot both the wide reef structure and a close-up of reef textures. So for example two 20mm lenses may be capturing the wide view while one 50mm gets some close-up content. These will not be combined so it is OK that the 50mm is collecting less surface area. Only the two 20mm need to proved full coverage.

I appreciate all the input. I'm reconsidering the compact (not mirrorless) cameras suggested here. Maybe I can figure out a way to lock the zoom level so that is not a concern.

 

[tursiops]

I shoot Sony A7R3 in Sea and Sea housing. This configuration is out of your budget range, and may be overkill for your application. Do you need interchangeable lens camera? If not, there are several good choices with fixed lens. Does it have to be high resolution? 10 years ago, 12 mpix cameras were giving great detail. Mirrorless may be the future but there are few if any advantages in underwater shooting where you are dealing with current, surge, buoyancy, etc, within a large housing.

Much of my photography initial learning was prior to the first commercially available zoom lens for 35mm cameras, the Zoomar, in 1959. Perhaps the use of "prime" to distinguish a lens from "zoom" changed around then, too. What is now called a "normal prime" (i.e., 50mm for a 35mm camera) was then just called a normal lens, to distinguish it from wide-angle or telephoto. When I started, there was no need for "prime" as a term, because that is all there was....you just had a lens. I certainly understand that the term today just means non-zoom. Which all misses the point; I ineptly raised the question in post #14 in an attempt to find out what focal lengths were being sought by the OP. Sorry for the tangent and confusion.

 

[tomh1972]

Honestly, it sounds to me like you want a full frame camera, rather than a 4/3 mirrorless. Given the same fl lens, the full frame camera will give you a larger (and somewhat “standardized”) view. No or little practical difference in pic quality, but you’ll have more pixels to work with in each shot. If you’re going to be stitching the photos together that might matter. Nikon z5, Sony a7 and similar might fit the bill.

 

[davehicks]

To answer a few questions, the depth will be shallower than 60'. Most of the reef is at 30-50' and the camera operator will be 10' or so above the reef when shooting. The shooting is like a lawnmower search pattern, with photo overlap between each line of photos. The cameras will be taking shots every second or so.

Regarding the prime lens, there are two thngs driving that choice. One is that I want no chance for error during collection of the images. We'll be somewhat remote and it is expensive to get there, so the data needs to be good. The two cameras are not redundant, they each will be canted slightly to shoot left-ish and right-ish. They need to be on the exact same focal length. The other reason for wanting replaceable lenses, specifically primes, is that sometimes there will be a need to shoot both the wide reef structure and a close-up of reef textures. So for example two 20mm lenses may be capturing the wide view while one 50mm gets some close-up content. These will not be combined so it is OK that the 50mm is collecting less surface area. Only the two 20mm need to proved full coverage.

I appreciate all the input. I'm reconsidering the compact (not mirrorless) cameras suggested here. Maybe I can figure out a way to lock the zoom level so that is not a concern.

What is your lighting setup going to be? Natural light or will you use video lights or strobes? At 60 feet your natural light is going to be pretty dim in all but the brightest and clearest water. At 10 feet distance and video lights you will need rather big lights.

If you are just using natural light, I am not sure you need to make such a big investment in camera gear. You might get very similar results with something as simple as GoPro's with appropriate wet wide lenses.

I'd you strongly suggest that you do a few trial runs in conditions that approximate your remote destination with a few configurations of cameras and lighting.

 

[Rick Brant]

Natural light but 60' would be the extreme. More typical will be 10-30'. Good idea -- I think I am going to connect with a few local owners and get some test footage. Aloha!