Canon 8-15, 140mm minidome and OMD-EM5II

I used this combination during my last diving vacation in August/September in Croatia and it will not remain the last time that I used this combination...

Part I.:

Camera: OMD-EM5II, Metabones 1x adapter & Canon 8-15mm fisheye (FE). 2x Sea&Sea Y-DS2.

Housing: NA-EM5II, 34.8mm N85-N120 adapter, 35mm N120 extension and Nauticam 140mm N120 minidome. Zoomgear was from Nauticam, but with additional selfconstructed 3D-printed extension collar (the 34.8mm adapter was built for using the 0.71x Metabones speedbooster that is 5.6mm shorter than the 1x adapter, so the zoomgear requires extension).

Background: The Canon 8-15mm FE provides diagonal angles of view (DAVs) from 170^o-85^o on MFT sensors (calculated, actual DAVs may be slightly different (e.g. 180^o @8mm)). For comparison, the rectilinear Pana 7-14mm provides DAVs from 114^o-75^o (this used to be my most used WA lens, but is practically unused UW since I have the Canon 8-15mm). The Canon hence covers the range from “real” fisheye (180^o) up to the range of extreme WA. In addition, corner sharpness and “rectilinear distortion” at wide angles (e.g. @7mm) at the rim of the image, are expected to be much better with the FE (at comparable DAV).

Sample images (reduced to 250 kB maximum - so real IQ is better):

ISO 1250; @8mm; f: 6.3; 1/25s

ISO 200; @8mm; f: 11; 1/250s

ISO 200; @8mm; f: 9; 1/250s

ISO 200; @8mm; f: 9; 1/250s

Part I (continued):

ISO 200; @15mm; f: 8; 1/250s

ISO 200; @14mm; f: 9; 1/250

ISO 1250; @8mm; f: 6.3; 0.5s

Part II: with Kenko 1.4x teleconverter

With the additional Kenko 1.4x teleconverter the focal length range is changed to 11mm - 21mm. The DAV range is 115^o – 60^o (For comparison 115^o DAV are provided by a 7mm rectilinear lens and 60^o DAV by 19mm). An additional 20mm N120 extension and a longer extension collar for the zoomgear are required also.

ISO 200; @11mm; f: 8; 1/60s

ISO 200; @11mm; f: 8; 1/250s

ISO 200; @21mm; f: 8; 1/250s

ISO 200; @17mm; f: 9; 1/250s

Before I had the Canon FE, my favorite WA lens was the Zuiko 8mm FE, but because of the very wide angle, I used the Pana 7-14mm more often. Both lenses remain unused since I have the Canon 8-15mm (but are still favorites of mine on the surface).

I also want to mention that I have a Tokina 10-17mm FE for sale (even with gratis zoomgear extension for MFT users that want to use the lens with 1x Metabones adapter instead of the 0.71x speedbooster). It gives similar results with the combination above, but I do not need it any more:

http://wetpixel.com/forums/index.php?showtopic=62911&hl=