>>4402243 (OP)
I mean you could buy the EF one and adapt it, that way you have both.

>>4402244
Why would I buy an EF lens for my OM camera?

>>4402245
OM film? When you said full frame I assumed you meant digital.

>>4402249
He also posted a Niggon lens in the thread pic.

>>4402249
yes
well circular fisheye is not really circular when you mount it on a crop camera
>>4402250
first image on google

>>4402253
If there's no zuiko lenses you want, I guess you gotta either look for a tamron adaptall or sigma. I think the widest tamron did was 17mm, not sure for sigma, but they did have those filtermatic lenses.

>>4402255
I'm not asking which lens to buy.
I'm asking whether a circular fisheye is useful for action photography or should I buy a normal diagonal fisheye lens?
I've never shot with an fisheye lens before.

>>4402256
That's not really something someone else can answer, it's sort of like asking someone else what you want. Look at some samples and decide which one you like. Fisheyes in general are pretty niche, and the circular one will be more niche, meaning there are fewer scenarios where you want to use it when speaking of photography in general. For action photography I see no reason why there would be a shot that would work on rectilinear and not circular unless your subject is cropped out

>>4402256
Nah fisheye is a certain artisitc direction. You'll get basically the exact same feel and style that you see on google from "fisheye skatepark photo". Reminds me of the early Chad Muska and Bam Margera videos for CKY. A rectilinear lens of the same or similar focal length will not give you that specific look, but would be more versatile. All depends on what your intention is and if you think it's worth the money for the amount of use it will see. I only bought an ultrawide once I could justify it for landscapes and tight indoors shots.

>>4402256
I shot with OP’s lens for a few years, trying to do what you’re talking about but for surfing & mountain biking. It’s very sharp, but it’s big and clunky, which limits where you’ll actually want to use it somewhat, and the zoom just ends up being an annoyance bc it’s never zoomed where you want it when you need it, you always have another adjustment to make & miss the action. In the end the best lens that I found was the nikkor 14mm aspherical prime on a d850. That was & probably still is my favorite rig for action. When I look back on the last 20 years of shooting, nearly all of my favorite shots were with that lens. I could write a page on why, and why the common criticism of that lens doesn’t matter, but gd, I really miss that setup. The circular edge distortion & matte can actually be added in post when you want it. The rest of the time, you have much more usable images with a lot less wasted pixels and great character w corner distortion & vignetting to work with.

File: Robin_Dodd_8-15_01.jpg (1.99 MB, 2000x2000)

1.99 MB JPG

>>4402243 (OP)

[EXIF data available. Click here to show/hide.]

Camera-Specific Properties:
Equipment Make	NIKON CORPORATION
Camera Model	NIKON D810
Camera Software	Adobe Photoshop Lightroom 6.10.1 (Macintosh)
Maximum Lens Aperture	f/3.5
Sensing Method	One-Chip Color Area
Color Filter Array Pattern	820
Focal Length (35mm Equiv)	8 mm
Image-Specific Properties:
Horizontal Resolution	72 dpi
Vertical Resolution	72 dpi
Image Created	2017:07:03 15:16:45
Exposure Time	1/125 sec
F-Number	f/8.0
Exposure Program	Manual
ISO Speed Rating	160
Lens Aperture	f/8.0
Exposure Bias	0 EV
Metering Mode	Pattern
Light Source	Unknown
Flash	No Flash, Compulsory
Focal Length	8.00 mm
Color Space Information	sRGB
Rendering	Normal
Exposure Mode	Manual
White Balance	Auto
Scene Capture Type	Landscape
Gain Control	None
Contrast	Normal
Saturation	Normal
Sharpness	Normal
Subject Distance Range	Unknown

File: P1055887_TIF_BW-edit.jpg (1017 KB, 1440x1080)

1017 KB JPG

I once had a 7.5mm (14mm FF) rectangular fisheye from Samyang. It was hard to get used to, and I decided that it wasn't for me.

>>4402243 (OP)
go full frame and buy the 8-15mm zoom, you'll get both in one lens.