DA 10-17mm f/3.5-f/4.5 Fish-Eye on Z-1p

Images

The "Wall" image didn't use a tripod. The "Target" images used a tripod and 2-second delay. They all obviously used the (tiny) built-in a lenshood. No filters were used.

The target wasn't big enough to include the corners, so a proper comparison between the centre, the edges, and the corners, isn't possible with these images. But the nature of the lens makes such a comparison pretty meaningless anyway.

I used aperture priority and autofocus throughout.

Teleconverter Focal length Wall Target  
(None) 10   f/3.5 f/8  
(None) 14 f/4 f/4 f/8  
(None) 17   f/4.5 f/8  
1.4 (Kenko) 14 (10 on lens)            f/4.9 (f/3.5 on camera) f/11 (f/8 on camera)  
1.4 (Kenko) 17 (12 on lens)   f/5.6 (f/4 on camera) f/11 (f/8 on camera)  
1.4 (Kenko) 20 (14 on lens)   f/5.6 (f/4 on camera) f/11 (f/8 on camera)  
1.4 (Kenko) 24 (17 on lens)   f/6.3 (f/4.5 on camera) (out-of-focus) f/11 (f/8 on camera)  

Discussion

I bought this for fun, but it has exceeded my expectations. A fish-eye lens probably isn't important enough to me to buy another, but I would be happy if I could use it, even with limitations, on a Pentax FF camera.

As far as I can tell, I could use this lens satisfactorily for its fish-eye effects at 14mm and 17mm. On an APS-C sensor the fish-eye effect is not strong at 17mm, but on an FF sensor it is more pronounced.

The lens is so strongly vignetted at 10mm and 12mm that I doubt whether I could get any extra value from it there. (But see below). Unless I were to use it with a teleconverter! Even at the widest angle most of the vignetting has gone. I can't judge from my tests what the edge and corner quality is with a teleconverter, but I am sceptical about the possibility that a fish-eye lens can sensibly be used with a teleconverter!

A reply to my Pentax Forums post about these tests pointed out that "... the only problem is the hood", and supplied a link to the following description of (dramatic!) removal of the hood to eliminate the vignetting of the Tokina equivalent of this lens: