Archived posting to the Leica Users Group, 2007/12/13
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Hi Ed, And there I was thinking: those are damn funky bags... Philippe Op 13-dec-07, om 15:38 heeft Eduardo Albesi het volgende geschreven: > Vick, > > There are noticeable color differences between using and not using > the IR cut filters. The degree of how much noticeable this effect > is depends on the particular lighting conditions of each scene. > There are light sources that are more IR rich than others, as > tungsten and halogen lamps. The sun is another high power IR > emitter, but the high emissions in the rest of the visible spectrum > tend to mask the IR artifacts of the M8. > Fluorescent light lacks typically IR emission in the M8 critical > band, so there's no problem under them. > > The following samples are under halogen light, with and without > filter, I think it cannot get worse than this: > http://gallery.leica-users.org/v/Fuchs/tech_001/IRNightmare1.jpg.html > > But it is effectively solved by the use of filters: > http://gallery.leica-users.org/v/Fuchs/tech_001/IRNightmare2.jpg.html > > Filter used is a B&W 486 UV/IR Cut filter. The lens is an Elmarit-M > 28/2.8 asph. > Both files shot in DNG, converted to JPG in Adobe Camera Raw (PS CS3). > > There is another IR contamination effect that affects the M8: a > soft focus 'glow' under certain circumstances. This latter effect > is caused by the superposition of a focused visible-spectrum image > and an out of focus IR image (remember that the IR plane of focus > is slightly offset from the visible plane of focus, hence the > different focusing IR mark on older lenses). This has been > extensively exposed on other fora, especially the LUF. > > So, just color correcting the files does not solve the IR issue. > But with high quality IR filters (B&W, Heliopan or Leica) you don't > have any side effects, and the increased color and focus precision > you get are worth their use. BTW, I have never noticed any image > quality degradation using either brand. > > So, just mount them on every one of your lenses, forget about them > and enjoy the camera, one of the very best out there. > > Ed > > > > > El 13/12/2007, a las 08:32, Vick Ko escribi?: > >> So, is there consensus on using IR filters on the M8, on lenses >> without >> coding? >> >> I've searched the archives a bit, and get the perception: >> * using the filter does degrade the image slightly >> * it does work, but the magenta flaw happens only under pretty severe >> conditions anyway >> * for the majority of photo conditions, the filter isn't necessary >> >> I've been tempted with an M8, from a very reliable source and very >> tempting >> conditions. >> >> >> ....Vick >> >> _______________________________________________ >> Leica Users Group. >> See http://leica-users.org/mailman/listinfo/lug for more information > > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information >