Archived posting to the Leica Users Group, 2006/11/15
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Henning, I'm really torn now. I really want the M8 with its increased IR sensitivity. I want the purple cast fixed as well. I'm afraid if I wait and Leica does a hardware fix that the IR sensitivity will be gone. I'm not really worried about the color shift with synthetic fabrics as thats not what I take a lot of photos of. I am worried about shots in sunlight where there is a lot of IR reflected off of foliage making landscapes look a little funny. Since I proved to myself that the hot mirror filter has no loss in the visible spectrum, that would be a good workaround if Leica did nothing. Nearly all the photos that Tina and others took look pretty good. So I guess the risk is diminished in my mind. I think I'm talking myself into something here. Len On Nov 15, 2006, at 5:36 PM, Henning Wulff wrote: > At 4:25 PM -0500 11/15/06, Leonard Taupier wrote: >> Mark, >> >> Great work. Your results are especially interesting to me as I >> want the kind of sensitivity to IR that the M8 has. I shoot a lot >> of IR photos. That's just the opposite of everybody else. I'm very >> familiar with the IR sensitivity of the D200 (none), the D2H >> (little more than average), D2X (a little less than the D2H), and >> D1X ( more sensitive than the D2H). The hot mirror IR filter >> approach may be fine in the short term but that's slowing down all >> your lenses by 1 to 2 stops. Since your experiment with the Phase >> One profile has only limited success, you're right. Leica will >> have to fix it. That may not be too easy as Leica has already >> suggested that adding an IR filter over the sensor may (my >> interpretation) mess up their edge performance they went so hard >> to develop). Your new Heliopan filter experiment will be >> interesting but I think the UV contribution to the problem is very >> minor compared to IR. Most modern lenses roll off UV fairly well. >> I have to use enlarging lenses for UV images. And your D200 also >> has absolutely no sensitivity to UV. It looks like a winner right >> now. While I want the IR sensitivity of the M8, not at the expense >> of color cast problems. For now I'll just wait and see how the M8 >> evolves and continue to buy more film for my M6 and M7s. >> >> Thanks and keep us informed on your future experiments. >> Len > > Len, my interests are also definitely more in the IR usability, and > less in colour accuracy. But the hot filter solution is definitely > the correct one, whether as part of the filter pack or front-of- > lens. Coatings and therefore flare are issues with lens filters, so > the more elegant, though one-sided solution is to add the > filtration to the filter pack in front of the sensor. > > Hopefully the B&W Digital M, should it materialize, will keep the > full IR sensitivity. > > -- > * Henning J. Wulff > /|\ Wulff Photography & Design > /###\ mailto:henningw@archiphoto.com > |[ ]| http://www.archiphoto.com > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information