I've brought this wide angle conversion lens for my 55mm ring the lens is actually a 46mm in enter but I've got stepdown rings and it fits quite nicely. But I get this bad distortion/blur/colouration in the corners. Why would this be? Is the lens not suited for my cam or is it because I'm stepping down too much? Here are a few shot small and one really big one so you can see exactly what I'm talking about...

BTW I had the cam on max focus, multi metering... AS you can see this problem extends completely around the edges...

Message edited on: 02/13/2006 07:01

i guess it's the problem of the stepping down... (one side) on the other side it guess it's simply the quality of the whole lens thing... good wide angle lenses are quite hard to produce... and the "wider" they are the more do they "bulge" the pic... from that side it's kinda normal... with an fisheye you'd have the extreme... the only suggetion for solution is to crop.... or try the correct sized lens by chance and see how the results are...

It appears also to be capturing the edges of the filter, or a lens hood if you have one.Probably because of the wide angle.You also seem to be getting a bit of a double image. It seems like there is a ghost around the subjects. But what do I know lol.

When you add another piece of glass not intended by the manufacturer (especially if it doesn't fit exactly - and you seem to have one smaller than the filter ring which is also giving you vignetting) you will usually have something called chromatic abberrations. This also happens with cheaper really long or really short focal length lenses. This is when the glass is not refracting the individual colors to the same spot - the Cyan, Magenta, and Yellow are misaligned on their projection points (digital sensor or film). Ever wonder why higher-priced really long (and really wide) lenses have APO in their names? The glass has been designed and calibrated to not give you the chromatic edging you see in your above images. Sorry to say, you're going to have to live with the edging - the flip-side is that now that you know what it does, pull it out and use it to effect the mood of the shot you're taking. It can convey something "dreamy" or the like. Play with it - have fun. I know a guy who modified a piece of a Schneider glass element to one of his lenses to get the middle in focus and almost a radial blur with REALLY BAD chromatic abberations spreading out - he used it for "dreamy" wedding shots - not my cup of tea but his clients seemed to love it! Hope that helps- -Lew ;-)

Tx all I'm going but today and might be able to get them to other a 52mm mount size for me so it'll only be a 3mm stepdown which really shouldn't be that bad. But reading on the website yesterday the lens is mad for video as well as still. would this be a harmful add in factor?

You'll probably notice some distortion, but most likely not as bad since that is what it might be designed for - it's closer to those lens filters and meant to spread that wide across.

Tx again, I've gone and returned the lens now, was really not happy with it... Lucky to get my money back...

Good for you, you can do better I think. :)