Recent content by petrochemist

I find the DA 10-17 (Fisheye) to be great fun. At the narrow end there's not too much distortion, and like all the others it's pin sharp.

Has anyone here tried taking photographs in UV? I've had a little play with it, and managed a few proof of concept shots (OOF but showing flower features not visible in visible light). To only record UV I've had to use one filter to block the visible and another to block the IR, (only...

Infra red usually focuses at a different point than visible light. Many older lenses have a IR mark to aid with manual focusing. Try taking some images with a much wider range of distances, with the camera focused on the middle ground. (A fence seen obliquely works well). If the problem is...

If you can't find any local sources, there are a number of sellers on e-bay who do them very cheaply (typically £10-15) & ship worldwide. All mine have come from this route, and give reasonable results, given my camera s unmodified. I've never noticed any signs of distortion or flare. I think...

Lovely shots, (1, 2, 5 & 7 are my favourites) but I don't think there's much infra red in the underwater shots. Water is pretty good at blocking infra red, and the hair colour doesn't show any of the typical IR violet colour cast.

As a newbie I thought I'd introduce myself with a couple of the IR shots I took in London last summer: Both taken with a unmodified Pentax K100d, fitted with a cheap 720nm filter, and a 50mm f1.7. The second is an experiment in (handheld) panorama stiching using Microsoft ICE.