[ Posted 23 March 2011 - 22:57 Republished by agreement ]One lens I bought many moons ago with the aim of using it for IR was the 300/4.5 ED Nikkor. Nikon aficionados will recognise this as a transition model from the old-school unit-focusing type of long lenses to the more modern designs featuring ED glass and internal (IF) focusing. It was amongst the first of the ED lenses and is special not due to its rarity, but for having zero focus shift from visible to IR. The workmanship of this classic is typical for Nikkors of those long gone days (ie. superb), and the tripod mounting foot is pitiful small showing some sins hark back to ancient times as well ....
Due to circumstances beyond my control, I got the lens cheap and except for a few test runs after its CPU surgery hadn't used the 300 much. A trip to Lofoten a few years ago, however, disclosed it might have birefringence issues for IR > 900 nm. Could also be an unhappy marriage to the D70 I combined it with at that time, though. So I found it prudent to re-test the 300 ED in preparation for the upcoming hectic IR season, using my standard D200 IR cameras. I am quite happy with the results so far, but the potential issue of image breakdown for landscape scenes (as I saw for the Lofoten imagery) remains unanswered because light wasn't conducive to that kind of shooting. Will have to rerun later to obtain a clearer picture of what, if anything, is going on.
Meanwhile, here is a typical 300 IR rendition of a snow-covered orchard. Nothing to complain about as far as I'm concerned.
