on January 3, 2011
This converter is designed for use with the 16mm f/2.8 lens for the Sony NEX cameras. It attaches to the front of the lens through a bayonet attachment which is hardly noticeable on the lens, and clicks into place, to prevent incorrect mounting and eliminate any danger of it being mis-aligned or turned while in use.
To my amazement, the first results with this converter show that images have higher resolution WITH the converter than when the 16mm lens is used without it. This shows that the lens and the converter were clearly designed with a view to being used together. Images produced with the converter in place are sharper and appear more contrasty, although this may just be a consequence of the increased sharpness, which in turn may in part be caused by the greater depth of field when the converter is in place.
In evaluating the need, or otherwise, for the converter, it must be borne in mind that the NEX 3 & 5 cameras have an APS-C-sized sensor. For those used to thinking in 35mm "full-frame" film camera terms, when mounted on the NEX, the 16mm lens on its own therefore provides coverage equivalent to a 24mm lens on a 35mm-format camera - nowhere near as wide as one may have thought. Adding this converter, which has a focal-length reduction factor of 0.75×, the resultant actual focal length is 12mm, equivalent to an 18mm lens on a full-frame 35mm-format camera. By any definition, this is a very wide-angle lens.
So, resolution, contrast and colour are excellent. What about chromatic aberrations and distortion? With the 16mm lens on its own, chromatic aberration (colour fringeing) is extremely low. In this respect, the 16mm lens is excellent. Adding the VCL-ECU1 does not result in ANY increase in chromatic aberration. Because of the resolution referred to above, it actually looks LOWER than when the lens is used on its own, and as the two components have been designed to work together, this may in fact be the case.
As regards distortion, there is some barrel distortion with the 16mm lens when used on its own. However, this is so low that it is unlikely to be noticed in real-life pictures unless there are straight lines very near the edges. It is easily correctable with standard software. Adding this converter results in a small increase in distortion, which appears as slight barrel distortion along the long edges of the frame. If you have rectangular shapes near the corner, you may observe that the image also appears to be pulled out slightly into the corners. Correcting for both of these distortions in software is not going to be easy. (If it were, one must presume that the lens designers would have corrected for it at the design stage.)
However, with most interior shots - with lots of vertical lines from walls, furniture, etc - in a real-life situation this very slight distortion is almost certainly not going to be noticed. With such a wide-angle lens, you are more likely to get standard perspective distortion (for instance, converging verticals), which is not a lens fault but a consequence of composition. If you want better than this, you will probably shoot - on a tripod! - with a top-end digital SLR with a wide-angle lens that will cost probably ten times the cost of this converter.
These results were much better than those seen on the web with the only picture that I could find that had apparently been taken with this converter. I assume that it must have been taken with a prototype version of the converter, which was subsequently improved. (We have certainly had to wait for it to become available!)
In normal interior shooting conditions, no vignetting (darkening of the corners) is noticeable with this converter in place. This is a remarkable result. Tests outdoors with a clear blue sky (not yet carried out), may show some variation in brightness, which one would expect to improve with stopping down of the lens.
The instructions warn that if the lens-converter combination is used with the tiny attachable flash, the converter may cast a shadow on part of the image. I have not tested this yet, but doubt if the flash would provide adequate coverage for such a wide angle anyway (nor would most flashes with most cameras).
The converter is supplied in a very smart, round, zip-up hard case that should provide excellent protection when it is off the camera. The petal-shaped lens hood or shade is an integral part of the lens, and front and rear caps are provided.
If you are shooting with a NEX 3 or 5 (or thinking of getting one), the combination of the 16mm lens and this converter will give superb wide-angle shooting, for interiors and cityscapes (with the limitations indicated above), landscapes, etc. Combined with the tiny camera body, this makes a superb back-up wide-angle outfit for people with very demanding expectations of image quality. For some people it will also be a superb main (or only) outfit - although these people are likely also to find a need for a longer lens (probably the excellent 18-55mm "standard" lens) for much general photography.
This converter is much better than expected and is unreservedly recommended.