Archived posting to the Leica Users Group, 2007/04/03
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Frank, Without the filters, image quality is actually worst than without the filters. The CCD is not designed to work in visible light without a near IR suppression of some sort. If it is included in the CCD package, as Leica engineers have chosen, it must be in front of the lens. Let's not be ingenuous. IR is part of the electromagnetic spectrum and is present everywhere. The frequencies that are not suppressed in the M8's CCD are reflected not only from some synthetic fabrics, but also from foliage, human skin, some metallic surfaces, etc. Some light sources are richer in IR than others, as tungsten lamps or the sun. Others are particularly poor in IR emission, as 'cold light' fluorescent tubes and power saving bulbs. So there is a continuum from situations with a lot of IR to others with almost no IR, but the CCD will always sense it, and the camera brain will interpret it in some way, be it as a diffuse out of focus glow around highly reflective borders, as a pervading magenta cast, as sensor blooming, etc. I think it is better not only as you say from a practical point of view, but also from a theoretic point of view to mount permanently the filters. Best, Ed El 03/04/2007, a las 20:30, Frank Filippone escribi?: > I am probably the most vocal to use IR filters + M8 all the time..... > > However, Erwin really was pretty careful in stating what the > problem with any filter is..... that you lose something in the > technical quality of your image.... reflections ( the example he > so cleverly showed) or contrast...... or something else. So > technically he is 100% right. Use the filter only when you must > if you want 100% of the best you can get from the M8, or any > camera for that matter. > > BUT...... there is a practical side too... one Erwin rarely makes > comment on, since he is more into the technical side.... > If you only use the filter when you must, this requires..... > Putting the filter someplace, taking your image, chimping that image > to see if there is a problem, finding where you put the filter, > putting it on the lens, then retake the picture......then remove the > filter and put it back into hiding. Proper? Yes. Practical.... > not really. > > Use the filters, 100% of the time, and go take pictures. Or are > you good enough ( rhetorical question aimed at precisely no one) > that you personally are not the lowest common denominator in image > quality? > > Frank Filippone > red735i@earthlink.net > > > > Am I the only one to find Erwin's suggestion about not using the > filters in general 'non-IR conditions' not that smart? > > I find consistently that the files I get with the filters on are > sharper and with more colour accuracy that when not used, *just in > almost any situation*. > The exception being perhaps only under pure fluorescent illumination, > when the IR contamination seems neglectible or nonexistant. > > Ed > > > > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information >