boilerdoc Posted January 28, 2007 Share #1 Â Posted January 28, 2007 Advertisement (gone after registration) I need a Series 6 IR cut filter for my 65 Elmar. B&H list a B&W 489 (not 486) IR blocking filter (>780nm). How close is this to the 486 that the M8 needs? Thanks in advance. Steve Link to post Share on other sites More sharing options...
Advertisement Posted January 28, 2007 Posted January 28, 2007 Hi boilerdoc, Take a look here B&W 489 filter Q. I'm sure you'll find what you were looking for!
ho_co Posted January 28, 2007 Share #2 Â Posted January 28, 2007 Steve-- If you haven't already looked at the B+W brochure, you can get the relevant section at Schneider Optics. You want page 26. Â The response curves of both have been posted on the forum several times. You can find them at Edmund Optics - Mounted IR Filters, although the diagram is rather small and hard to decipher. What they list as UV/IR cut is the 486; what they show as KG-3 is the 489. Â The two are slightly but definitely different, and you'll have to decide what to do. The 489 doesn't cut UV to the degree that the 486 does, and that might make a difference with a lens as old as the 65 Elmar. Â If you shoot with several lenses in the same situation, you may see some difference in color when changing filtration. Â On the other hand, depending on what you shoot, the IR problem might not be a big one for you, and either filter might do as well. Â Maybe someone else can be more specific. Â It would probably be fine to try the 489 unless you know that your needs simply don't allow color variations (which will likely be minor anyway). Â Good Luck! Â --HC Link to post Share on other sites More sharing options...
rvaubel Posted January 28, 2007 Share #3 Â Posted January 28, 2007 You should know that the 489 is an absorbtive filter, i.e. dyed glass. It is not as much of a cut filter as the 486. It would be fun to play with but the 486 is the one that, so far, seems to be the better choice. Â Rex Link to post Share on other sites More sharing options...
carstenw Posted January 28, 2007 Share #4 Â Posted January 28, 2007 Doesn't the 489 have an exposure factor? Link to post Share on other sites More sharing options...
rebride Posted January 28, 2007 Share #5 Â Posted January 28, 2007 Doesn't the 489 have an exposure factor? Â Yes, the exposure factor is 1.2. Â Dejan Link to post Share on other sites More sharing options...
Guest guy_mancuso Posted January 28, 2007 Share #6 Â Posted January 28, 2007 Yes it does have a exposure factor your normal ISO 160 would be ISO 100. Also a completely new profile would need to be made for it because it is green. Although I would still like to try it , there would be no cyan corner issues. Link to post Share on other sites More sharing options...
roubaix Posted January 28, 2007 Share #7 Â Posted January 28, 2007 Advertisement (gone after registration) Howard, Â Thanks for the link to the B+W handbook. Very helpful. Â Peter Link to post Share on other sites More sharing options...
lars_bergquist Posted January 28, 2007 Share #8 Â Posted January 28, 2007 Steve--[--------------------------] Â The two are slightly but definitely different, and you'll have to decide what to do. The 489 doesn't cut UV to the degree that the 486 does, and that might make a difference with a lens as old as the 65 Elmar. [--------------------------] Â --HC Â If your 65 mm Elmar takes series filters, then it should be a late, black chrome model, and Leica lenses later than about 1960, like this one, do not need UV filters. Glass choice, coating technique and cement type take care of the UV radiation 'internally'. Too bad Leica cannot do the same with IR ... Â Also, I understand that a 489 filter will also remove some visual red, and thus cause a visible green cast. Â The old man from the Age of Orthochromatic Films Link to post Share on other sites More sharing options...
robsteve Posted January 28, 2007 Share #9  Posted January 28, 2007 I need a Series 6 IR cut filter for my 65 Elmar. B&H list a B&W 489 (not 486) IR blocking filter (>780nm). How close is this to the 486 that the M8 needs?Thanks in advance. Steve  Steve:  B+W will make their filters in any of their avaiable mounts, including a series 6 486 UV-IR filter. You just have to get your dealer to order it. I have done this in the past for series filters and though it can take a month or two, the filter arrives in the mount specified and at not extra charge. Link to post Share on other sites More sharing options...
rvaubel Posted January 28, 2007 Share #10 Â Posted January 28, 2007 Yes it does have a exposure factor your normal ISO 160 would be ISO 100. Also a completely new profile would need to be made for it because it is green. Although I would still like to try it , there would be no cyan corner issues. Â Actually, the ISO would be 128. That's less than I/3rd of an F stop. This filter is the same filter that many digital cameras use as a base over the sensor. Over this absorbtive filter (BG 38 as I recall) the reflective cut filter layer is applied. There are better absorbtive filters out there but are not available to the consumer market. Â If I remember correctly, the BG 38 (489) is the filter Leica uses over the sensor. Â Rex Link to post Share on other sites More sharing options...
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