Archived posting to the Leica Users Group, 2008/04/23
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Hi Bob, I think that it is a discussion worthy of a thread. As to the basic properties of a UV filter, I thought that this was well recognized to reduce the appearance of haze or a blue cast in cloud, sky and landscape photography. Someone will perhaps point out that it is not the correct tool for that particular function and technically that ought to be a skylight for the blue cast, I guess. I don't consider that it was significant at all that the filter was in place for this shot, except perhaps to start with the most neutral colour before the conversion. Seeking after technical process perfection in the classical amateur photographer vein. I mentioned it only as a comparison to the (polarised) previous cloud shot. Actually I shot some more today and there is an amusing tale associated with that. News at eleven to follow on that particular appalling event! As you mentioned people seem to have emotive positions on routinely leaving a filter in place for its mechanical protection of the front element. We shan't stir that particular pot! For myself, while I actually never had filters on any of my Leica glass with the M7 except for a specific effect, I now leave the UV/IR on all of them all of the time. I like lens hoods anyhow and they have a bonus of a little mechanical protection too. I see no practical effects except of course when the Magenta Fairy might otherwise have cast her evil spell on people stuff. I have enough pics of wife and children dressed in purple already. The only inconvenience is where only one of my lenses is coded and this means changing the menu selection for the lens detection if I am being particular. Again, I regard the practice of capturing the largest number on tonal values in the original Raw file as vastly more important. Maybe that is another discussion. Cheers Geoff http://www.pbase.com/hoppyman/e http://gallery.leica-users.org/v/gh/ -----Original Message----- From: lug-bounces+hoppyman=bigpond.net.au@leica-users.org [mailto:lug-bounces+hoppyman=bigpond.net.au@leica-users.org] On Behalf Of Bob Adler Sent: Wednesday, 23 April 2008 13:42 To: lug@leica-users.org Subject: RE: [Leica] IMG: M8 BW conversion Hi Geoff, You're correct; I'm not speaking of shooting in JPEG. I shoot RAW only also and process in Lightroom and CS3. And as you correctly stated, I'm not talking about doing IR photography. I am curious as to why you say a UV enhances clouds and sky. I've not heard of that before and I'm very curious to know why that is so. I may have to go out an buy a whole bunch of those puppies! :-) Just now I don't see the need for using the IR filter unless I'm shooting under incandescent lights and dark clothes. I read somewhere that having increased IR sensitivity (i.e., without the IR filter) enhances gradations in the blacks. That's all I was curious about; if anyone with more knowledge than I might know if this is so. Probably not discernable. Maybe some day I'll shoot an image with and without to see if I notice a difference. But I see no value in using the IR filter unless I want color under the above conditions. It doesn't add anything to RAW images converted to BW, and may detract from the lens' abilities (just my opinion about filters in general; don't want to start a filter/no filter thread here please). Best, Bob Date: Wed, 23 Apr 2008 10:10:44 +1000 From: "Geoff Hopkinson" <hoppyman@bigpond.net.au> Subject: RE: [Leica] IMG: M8 BW conversion To: "'Leica Users Group'" <lug@leica-users.org> Message-ID: <003301c8a4d6$7954db20$6b01a8c0@dadquad> Content-Type: text/plain; charset="US-ASCII" Hi Bob, are you referring to shooting in the BW mode, which would be a colour saturation mode for jpegs? In my opinion that is throwing away an ernormous amount of information and control. I only shoot in Raw, hence RGB, not greyscale files. Generally speaking, a UV makes sense for photos of the sky and clouds anyway. All of my lenses have UV/IR filters fitted full time. I'm working on coding some of them (only my 50 is 6 bit). Raw and processing in Adobe Camera Raw/Photoshop CS3 offers huge advantages, including when the intent is to convert to a greyscale file (or toned BW). That combination offers by far the largest number of possible tones, which may be placed as you wish within your dynamic range. What's that for an M8, maybe 6 stops?? Someone with more experience than I might like to chime in there. Those 3 gazillion linear tones get morphed into our non-linear way of seeing stuff. In the end the files are much more robust and hence editable. If you have a chance, take a look at what Lightroom or ACR and/or PSCS3 will do for you in new BW options. I follow your point on not wanting to filter IR and I'd be very interested to see anyone's work displaying examples there. I confess that I am not personally enthusiastic about IR photography, but I don't think that you are referring to that specifically. Cheers Geoff http://www.pbase.com/hoppyman/e http://gallery.leica-users.org/v/gh/ -----Original Message----- From: lug-bounces+hoppyman=bigpond.net.au@leica-users.org [mailto:lug- Subject: Re: [Leica] IMG: M8 BW conversion Geoff, Wondering why you leave the UV/IR filter on. I've only been using it indoors with people (clothing) photography (when I remember to put it on...) My understanding is that the M8 provides better gradations of gray because it doesn't have an IR filter on the sensor. Thus I'm thinking that for BW not using the filter makes for more information. This just from my readings; it may be just theory... Any thoughts? Thanks, Bob Bob Adler Palo Alto, CA http://www.raflexions.com Date: Wed, 23 Apr 2008 01:26:15 +1000 From: "Geoff Hopkinson" <hoppyman@bigpond.net.au> Subject: [Leica] IMG: M8 BW conversion To: "'Leica Users Group'" <lug@leica-users.org> Message-ID: <000101c8a48d$34692870$6b01a8c0@dadquad> Content-Type: text/plain; charset="US-ASCII" Still playing with BW conversion from M8 DNGs. This is from walking the dog here recently. We've been having Graham clouds here several times a week for six months or so. Bless you La Nina. UV/IR only. PSCS3 conversion simulating deep red and blues tweaked further. Even put some grain back for nostalgia. <http://www.pbase.com/image/95983277>