Guest guy_mancuso Posted April 13, 2007 Share #1  Posted April 13, 2007 Advertisement (gone after registration) Okay as i reported the leica filter at 21mm looked perfect and the B+W was pretty close. This is from the WATE  Now if you look at these closely you will see a slight cyan cast left by the 21mm and the B+W BUT BUT BUT look again the B+W overall is slightly green to begin with globally the leica is more warm but actually more accurate  Ist is the leica filter 2nd is the B+W 3rd is a tweaked version of the B=W to match the color of the leica filter  So the bottom line is the B+W at 21mm can match the leica filter with a slight adjustment and the cyan cast almost completely fades but the Leica is more true. I still recommend the Leica filter but you can easily cheat here even though there is a slight cyan corner left after the tweak on the B=W it is pretty darn good as i have reported earlier this proves it Link to post Share on other sites More sharing options...
Advertisement Posted April 13, 2007 Posted April 13, 2007 Hi Guest guy_mancuso, Take a look here WATE at 21mm B=W VS Leica filters. I'm sure you'll find what you were looking for!
LJL Posted April 13, 2007 Share #2 Â Posted April 13, 2007 Guy, Thanks for posting this. I think it helps folks undestand and see things. The one point that still needs to be taken into account, as mentioned in another thread, is that the WATE is f4 while the 21 Elmarit is f2.8, and that may cause a bit more cyan contamination for the larger aperture. Â Anybody that can test to prove/disprove this will be helpful to many. Thanks. Â LJ Link to post Share on other sites More sharing options...
Guest guy_mancuso Posted April 13, 2007 Share #3 Â Posted April 13, 2007 Exactly LJ and after this little test i am going to make the bet the leica filter is really what you want on the 21 elmarit Link to post Share on other sites More sharing options...
LJL Posted April 13, 2007 Share #4 Â Posted April 13, 2007 As an aside, and this may be the wrong thread for this, but I will toss it out there anyway.... Â Just got the new lens mount from Zeiss for my 25/2.8 Biogon to bring up the 24/35 framelines instead of the 28/90 as it ships. Once I get it installed and successfully hand coded, I will attempt to test a B+W versus the Leica UV/IR filter on that lens also. My gut is telling me that there might be a simliar "marginal" difference, but I will wait to confirm that. (May take a few more days, as I have lots of equestrian and polo to shoot this weekend, so I will be busy.) Â As it is looking, I am agreeing with Guy that folks should probably be using the Leica UV/IR cut filters on the the CV 15, the WATE, the 21 Elmarit, and we still have to see about the 24 Elmarit and Zeiss 25/2.8 Biogon. I think that the only other one that could possibly have just a bit of cyan contamination is the 28/2.0. Anybody that confirms or refutes that is a hero for all of us. Thanks. Â LJ Link to post Share on other sites More sharing options...
scott kirkpatrick Posted April 13, 2007 Share #5 Â Posted April 13, 2007 Hey guys, while vignetting in the luminance channel increases with increasing (wider) aperture (because you can't see the whole opening from the corners of the image plane), the color effects are relative effects, and do not depend on aperture. This is true in theory, and was shown true by Sean's experiments. (And analyzed more accurately than you can see in a small jpeg in my article that Sean hosts, linked in at the very end of the 28 mm lens comparisons.) So if you like what you see at f/4.0 you will like it at f/2.8 or f/8.0 in a given lens. Whether the firmware works equally well for all lenses and for Leica lenses vs Leica "impersonators" is another story, but it doesn't depend on aperture. It depends on different lens design approaches (more vs less telecentric) and on color shifts and the color of light used in the picture. And finally on how good a job Leica has been able to do in covering all their lens inventory. Â scott Link to post Share on other sites More sharing options...
LJL Posted April 13, 2007 Share #6  Posted April 13, 2007 Hey guys, while vignetting in the luminance channel increases with increasing (wider) aperture (because you can't see the whole opening from the corners of the image plane), the color effects are relative effects, and do not depend on aperture. This is true in theory, and was shown true by Sean's experiments. (And analyzed more accurately than you can see in a small jpeg in my article that Sean hosts, linked in at the very end of the 28 mm lens comparisons.) So if you like what you see at f/4.0 you will like it at f/2.8 or f/8.0 in a given lens. Whether the firmware works equally well for all lenses and for Leica lenses vs Leica "impersonators" is another story, but it doesn't depend on aperture. It depends on different lens design approaches (more vs less telecentric) and on color shifts and the color of light used in the picture. And finally on how good a job Leica has been able to do in covering all their lens inventory. scott  Scott, That is a much better way of communicating this. Your point is exactly what we are thinking about here....lens design, and not just changing the aperture on the lens. So the design of the 21 Elmarit will determine how and which filter works best, not it just being an f2.8 lens compared to an f4 on the WATE. However, until we test some of this out, it is still somewhat speculation, or better, educated gut feelings The issue is still at what angle of reflectance and incidence do the B+W and Leica filters differ, and how does that translate to which lens.  LJ Link to post Share on other sites More sharing options...
arthury Posted April 13, 2007 Share #7 Â Posted April 13, 2007 Advertisement (gone after registration) The B+W seems a little cooler in temperature. Link to post Share on other sites More sharing options...
Guest guy_mancuso Posted April 13, 2007 Share #8 Â Posted April 13, 2007 Yes Arthur it is a little cooler and i think this is what you will see exactly through the use of the B+W vs the use of the leica filter and in another thread i mentioned this , the M8 is tweaked for the leica filters but this is also a global adjustment so very easy to fix this through WB which is what I did not do here , I want to see that difference because i suspect teh leica filter is a little weaker or better match to the existing IR filter on the sensor. So besides the recommendation from 24 up on B+W or Leica folks can still use the B=W but will be a little cooler compared to the leica but the cyan cast is still removed from 24mm up the only shift will be a slight color one. This is actually what i expected and is also very easy to deal with. Â Yes Scott the one thing i did not mention there is the 21mm setting on the WATE identical to the Elmarit 21mm because they could be different in actually FL so the 21mm elmarit needs a test. Â This is another one of those threads that folks need to see because you can understand visully what to expect and Sean will probably do this in more detail and make a article but this gives us a real clue what is going on Link to post Share on other sites More sharing options...
sean_reid Posted April 13, 2007 Share #9 Â Posted April 13, 2007 I have a 21/2.8 Elm. here and will be doing controlled chart tests soon. That will tell us about how well the cyan drift is corrected by the new firmware for M8 + 21 + 486. To know how well the color rendering does, we really need to look at samples shot with a WhiBal card so that accurate WB can be set in RAW conversion. Â Cheers, Â Sean Link to post Share on other sites More sharing options...
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