uptong Posted July 19, 2011 Share #1 Posted July 19, 2011 Advertisement (gone after registration) Having picked up on a 'tip' by Brett at a Leica lecture I decided to try it out and set a fixed manual 5800k colour temp, for some outdoor shooting on my M8. Wont go into the ins and outs of why etc as that is really irrelevant. Suffice to say that a little anomaly crops up when importing the images for processing. Bringing the images into Lightroom, Photoshop CS5 show the colour temp as 6150k, Aperture shows 6149k. Bit of background info, M8 has latest firmware, has recently been to Solms for the fixing of another issue so has been serviced and set up by the factory very recently. And yes have tried a variety of lenses both leica and VC which are all fitted with IR/UV's of both Leica and B+w branding, so have discounted any particular lens/filter combo being cause, all show same 6150k as colour temp. Have of course double checked camera setting and 5800k is defiantly set and using in camera info on LCD display shows 5800k. Anyone else noticed similar? Its not an issue I will loose sleep over as its no real big deal, just an intriguing anomaly that someone may have an answer too. Link to post Share on other sites More sharing options...
Advertisement Posted July 19, 2011 Posted July 19, 2011 Hi uptong, Take a look here Colour Temp Anomaly. I'm sure you'll find what you were looking for!
sandymc Posted July 19, 2011 Share #2 Posted July 19, 2011 The reason for this is the following: color temperature is not actually recorded as color temperature in the DNG files that M8's (or M9's) produce - it's recorded as a white point in XY color coordinates. The reason for the difference between raw converters is that there is no industry agreement as to what color temperature corresponds to a given XY. So there are differences between what e.g., the M8 and Aperture and LR will show as a color temperature. Even though they are looking at the same XY white point. Sandy Link to post Share on other sites More sharing options...
mjh Posted July 19, 2011 Share #3 Posted July 19, 2011 The camera is storing the user-selected colour temperature in the proprietary MakerNotes (it’s not part of the EXIF standard), but not if you are using a WB preset, for example. It’s quite possible that your raw conversion software is ignoring this data, maybe because it wouldn’t always be available. It may deduce the colour temperature based on other meta data instead. Colour temperature is only an approximate way of describing the spectral distribution of ambient light anyway. Link to post Share on other sites More sharing options...
uptong Posted July 19, 2011 Author Share #4 Posted July 19, 2011 Thanks for the explanations guys. Appears as I was thinking the numbers are really arbitrary figures in the real world. As I said its nothing to loose sleep over, the small difference in set and recorded figures has little or no effect over the principal that was being spoken about. Was simply intrigued as to what was may cause the anomaly in reporting, you have cleared that up in my mind. Just like the worlds economic situation - at end of day they are just numbers! Link to post Share on other sites More sharing options...
sandymc Posted July 19, 2011 Share #5 Posted July 19, 2011 The camera is storing the user-selected colour temperature in the proprietary MakerNotes (it’s not part of the EXIF standard), but not if you are using a WB preset, for example. Not that it makes a major difference, but what LR and Aperture are looking at is stored (in a DNG anyway) in either the AsShotNeutral or the AsShotWhiteXY tags, which are part of the DNG specification, not the MakerNotes. So far as I am aware, they don't use the MakerNotes for WB. In fact, I don't think that Aperture decodes the MakerNotes at all. Sandy Link to post Share on other sites More sharing options...
mjh Posted July 19, 2011 Share #6 Posted July 19, 2011 So far as I am aware, they don't use the MakerNotes for WB. Yes, that’s what I had suspected (“It’s quite possible that your raw conversion software is ignoring this data”). Link to post Share on other sites More sharing options...
CharlesL Posted July 21, 2011 Share #7 Posted July 21, 2011 Advertisement (gone after registration) I, too, notice that my main processing program, Picture Window Pro, opens M8 DNGs and reports a Kelvin temp about 300K greater than set. Thanks, gentlemen, for the explanation. Incidentally, some other cameras let you set not only color temp but also a magenta-green shift on a scale of -3 .. +3. Even if you process raw files, a more accurate setting helps you review shots upon transfer to computer for decision whether to forget the shot or bring out its potential. Also, starting from a good setting shortens post-processing time hunting for the temp and tint that brings out the best. Link to post Share on other sites More sharing options...
bybrett Posted July 21, 2011 Share #8 Posted July 21, 2011 Great advice. My answer is that they all have different thermometers but the temperature is the same... Link to post Share on other sites More sharing options...
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