7Artisans 4 mm

[bvanant]

I am looking for a circular fisheye for an OM-1. The 7-artisans 4 mm looks interesting, has anyone shot it underwater?

thanks

Bill

[SFEgr]

The center image if the 5 photo medly on the manufacturers web page shows a funny little knob (focus?) protruding from the side barrel. I assume that is removable?

[Architeuthis]

I cannot say about the Artisan 4mm fisheye from my own experience, but the lens looks short and it has a 225° circular angle of view. Probably it will be difficult to place in a housing and put a dompeort in front without vignetting. I assume it is manual focus what means you will need a focus gear for focusing on the virtual image of the dome (setting focus just close to infinity will not be enough)...

 

I have used the Sigma 4.5mm circular fisheye (https://www.sigma-global.com/en/lenses/45_28/) with Canon EF mount via Metabones 1x adapter on Olys EM5II and EM1II. Since the lens has substantial length, there were no problems with placing in it Nauticam housing and using domeports with appropriate extensions. It also is a lens with AF. Optical quality is, more or less, what you expect from such a lens, it is reasonably o.k., but not as good e.g. as Canon 8-15mm @8mm on FF (Sony A7R5)...

 

Wolfgang

Edited February 25 by Architeuthis

[Chris Ross]

Hunting around on the webpage found a diagram showing the lens is 54mm from bayonet to top of front element, which is almost the same size as the the Panasonic 8mm.  This suggests it would be close to working with a fisheye dome and no extension, same as the Panasonic lens, however with a 225° field it would need to sit a little forward of where a 180° fisheye would.  It's probably something you would need to try in the housing to confirm. 

 

I would agree though that the Sigma with AF might be a better option, though you would have to hunt around to buy one second hand.