This review was planned to help choosing some low budget superwide solution for my 350D. The cheapest solution that came to mind was to buy a conversion lens. I found some auctions for Hyundai CL-58W05X 0.5x Superwide Macro Attachment lenses at Ebay and picked one up for 2€ new plus shipping. After some test pictures I sold it and bought a Zenitar 16mm. For people in a similar situation I will keep these test pictures here for reference. The test procedure was simple, I just put my cam on a tripod in direction of some bright motif. Then I shot to CR2, converted to TIF in Rawshooter, resized in Photoshop and saved as grade 9 baseline JPG. Nothing was changed, neither color nor exposure or sharpness (cam settings were set to 0 too).
Picture No. 1: reference shot with an EF 28-105mm F3.5-4.5 USM II at 28mm F16, 1/25s
Picture No. 2: shot with the EF 28-105 and Super Wide lens at 28mm F16, 1/20s
Picture No. 3: second reference shot with an EF 20-35mm F3.5-4.5 USM at 20mm F16, 1/20s
Conclusion: The Tube of the Hyundai CL-58W05X 0.5x Superwide Macro Attachment lens was made from metal, giving the lens some good weight to handle it and making sure the screw thread will last for a while. On the EF 28-105 the promised 0.5x conversion was by no means achieved, in comparison with the EF 20-35 you can see that it was around 0.8x only (as pointed out sometimes in other articles and product descriptions these adapters are made for 50mm lenses, so the 0.5x effect will most likely result in a 25mm wide angle there). The picture quality can shortly be described as bad as shit. It's enough to take some party shots at daylight and considering the price I paid that is ok, but for everything else you can't use the lens, as there are distinct signs of chromatic aberration, lush contrast and lush sharpness - and speaking of chromatic aberrations and sharpness, these pics were shot at F16, where most lenses perform at optimum. Expect the worst for open aperture/available light photography.