richam Posted September 22, 2008 Share #1 Posted September 22, 2008 Advertisement (gone after registration) I noticed a central hot spot when using the M8 with an IR pass filter and the 28mm Elmar at small apertures. The lens is the latest one, purchased new about a year ago, serial 4006330. To check, I ran some tests. The columns are f2.8 on the left to f22 on the right, one stop per column. The first row is the 28mm with IR cut filter, 2nd row 28mm with B+W 092 (dark red IR pass) filter, 3rd row 28mm with B+W 093 (opaque IR pass) filter, 4th row is the 35mm CV Nokton with 092 filter, and last row is the 21mm Elmar with 092 filter. (I'm traveling right now and don't have any other lens/filter combinations with me). On the 28mm, the hot spot starts to show up about f11 with the 092 and f8 with the 093 filter. It is quite pronounced at f22. There is no hot spot with the IR cut filter. Neither of the other two lenses shows any hot spot whatever. Has anyone else noticed this? Has it occurred with any other lenses? [ATTACH]104264[/ATTACH] Link to post Share on other sites More sharing options...
Advertisement Posted September 22, 2008 Posted September 22, 2008 Hi richam, Take a look here IR hotspot on 28mm Elmar. I'm sure you'll find what you were looking for!
jaapv Posted September 22, 2008 Share #2 Posted September 22, 2008 There are a nmber of lenses suitable for IR photography, but many others show this hot spot. I have very good results with a Summaron 35/3.5 I general I find older lenses tend to be better at this kind of thing. Link to post Share on other sites More sharing options...
casin Posted September 22, 2008 Share #3 Posted September 22, 2008 I noticed that just yesterday with my 28mm ElMarit. I used an IR Hoya R72 filter. Exactly as it happened to you... Link to post Share on other sites More sharing options...
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