Archived posting to the Leica Users Group, 2008/06/16
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Steve Barbour wanted to see an A/B comparison of an M8 shot with and without an IR filter. My newly-acquired VC 35/1.2 arrived today (yeah, I bought one). While I was checking it out, I took the same wide-open shot without an IR filter (left) and with the filter (right). Tungsten lighting, three 40w bulbs above my bathroom mirror. http://users.2alpha.com/~pklein/temp/IRNofiltVsFilt.jpg Here's the whole frame of the IR filtered shot, uncropped but greatly reduced, for reference. http://users.2alpha.com/~pklein/temp/IRFiltFullFrame3382.jpg I stood on the exact same spot with both feet, and focused on my eyeball for each shot. Shot RAW, converted in Capture One with the JFI Plain BW profile. Identical exposures, 1/360 at f/1.2. Default Capture One settings, so the same amount of sharpening was applied to each. Notice the differences in tonal rendition and contrast, not to mention the sharpness of my eyelashes and receding hair line... :-) This is completely consistent with other test shots I've made with other lenses on a tripod. Since it shows a real person rather than cereal boxes or soup cans, I thought it would be a reasonable real-world demonstration of what happens. The IR makes the skin a little lighter, and reduces the sharpness and contrast a little. You might be able to play with local contrast and get back some of the crispness of the filtered shot, but the differences in rendition between the filtered and unfiltered shots remain. All other things being equal, I prefer to use the IR filter while shooting B&W with the M8. However, I have noticed that you can often gain a half stop more exposure without the filter, especially in reddish tungsten light. So if I was shooting at 1/15 or slower, I might remove the IR filter, figuring that the half-stop faster shutter speed I'd get might gain me more in clarity than the IR smearing would take away. --Peter