Archived posting to the Leica Users Group, 2007/10/12
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Hi Howard, I have no problem with the Tri-Elmar or the 28mm Elmarit or any other wide angle lens I've tried with the exception of the 28mm Summicron. It appears to be a characteristic of the specific lens design and not the focal length. I took quite a few IR photos with the Tri-Elmar last year. I could not include it in my test today as it's in New Jersey getting 6-bit coded. How's the new M8 working out? Cheers, Len On Oct 12, 2007, at 9:37 PM, Howard Cummer wrote: > Dear Len, > How about the 28mm setting on the TriElmar? I have shot many IR > photos using this lens and did not notice the hotspot phenomena you > experienced with the Summicron. > Cheers > Howard. > > On 13 Oct 2007, at 9:06 AM, lug-request@leica-users.org wrote: > >> Date: Fri, 12 Oct 2007 20:51:42 -0400 >> From: Leonard Taupier <len-1@comcast.net> >> Subject: Re: [Leica] George: 28mm Summicron IR problem >> To: Leica Users Group <lug@leica-users.org> >> >> In addition to the sensitivity of the sensor the quality of digtal >> infrared depends on the characteristic of the lens. >> >> For example, the Canon EF-S 18-55mm f/3.5-5.6 typically produces a >> pronounced hot spot as can be seen in the sample picture to the left. >> The hot spot is a a result of internal reflections within the lens >> produced by the lens' coatings. Some types of coating are not >> transparent to near-infrared wavelengths. >> >> The above was taken from a web site dedicated to Infra Red digital >> photography. Quite a few lenses are listed which produce these hot >> spots. The author did not include Leica lenses in the recommended or >> hot spot producing lists. >> >> Len >> > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information