renapearl Posted February 14, 2011 Share #1 Posted February 14, 2011 Advertisement (gone after registration) I've had my M9 just on a week after upgrading from an M8, which I loved and got great quality images. So far not so with the M9 - mainly to do with focus and shallow depth of field even at F11! But for this post it is to do with incorrect lens information shown in Lightroom. I was testing my Elmarit 90mm F2.8 lens, which I never used on my M8, but did have it coded. I was mainly testing because of the focus seeming to be out, but when I downloaded the images to Lightroom I noticed that the lens information was incorrect. As follows: The camera was on a tripod 1st shot - F8 set on the lens, shown in Lightroom as F4. 2nd shot - F5.6 set on the lens, shown in Lightroom as F8 3rd shot - F4 set on the lens, shown in Lightroom as F4.8 The shutter on the camera was set between 30 and 60, shown in Lightroom as S30. I had a light meter in the shot showing the read out of the lens setting, and have did the test twice with the same results. Any comments or thoughts would be most welcomed. Link to post Share on other sites More sharing options...
Advertisement Posted February 14, 2011 Posted February 14, 2011 Hi renapearl, Take a look here M9 incorrect EXIF information ???. I'm sure you'll find what you were looking for!
wda Posted February 14, 2011 Share #2 Posted February 14, 2011 Welcome to the Forum, renapearl! Have you set your camera to recognize the lens? Link to post Share on other sites More sharing options...
renapearl Posted February 14, 2011 Author Share #3 Posted February 14, 2011 Thanks for making contact. The lens is coded, And the lens detection within the menu is on auto. Link to post Share on other sites More sharing options...
Nicoleica Posted February 14, 2011 Share #4 Posted February 14, 2011 Hi and welcome Renapearl. As with your M8, the aperture information in the exif data is an estimate only. Calculated from a difference in readings between the external sensor and the TTL meter reading. This is then combined with the max aperture information from the lens coding, and an estimate is duly arrived at. It's probably a little more complicated than that, but I'm sure you get the idea. Sometimes this estimate can be spot-on, at others it can be wildly off. Especially if any extra light or shadow affects the external sensor. Is your lens code reading correctly otherwise? (Showing the correct lens type etc?) The shutter speed reading is probably due to you using an intermediate speed in manual mode. In auto it should show the correct speed. Hope this may be of help. Link to post Share on other sites More sharing options...
250swb Posted February 14, 2011 Share #5 Posted February 14, 2011 Thanks for making contact. The lens is coded, And the lens detection within the menu is on auto. You do realise the camera only makes a guess at the f/stop don't you? There is no electrical or mechanical link between lens and body that will give a totally accurate f/stop reading all of the time, particularly if the camera is set on manual exposure where the internal brain (such as it is) doesn't know what part of the scene you are metering from. Steve Link to post Share on other sites More sharing options...
renapearl Posted February 14, 2011 Author Share #6 Posted February 14, 2011 Nicoleica, Many thanks for the explanation. I'm getting to bogged down with testing way images are 'soft'. And thanks Steve for your input. Rena Link to post Share on other sites More sharing options...
Washington Posted February 19, 2011 Share #7 Posted February 19, 2011 Advertisement (gone after registration) I can only suggest that the metadata is totally meaningless regarding the problem you have encountered. What you see is what you have. If you have had success with an M-8…… and now you find that your M-9 is not focusing properly, my best guess would be something is amiss in the rangefinder. Have you used more than one lens? If so, what about the issue with it? Is nothing sharp? Link to post Share on other sites More sharing options...
mweiner Posted February 19, 2011 Share #8 Posted February 19, 2011 renapearl, you mentioned looking at the exif data in lightroom so I assume you are evaluating the sharp/soft of you images in lightroom -- which is what you should be doing. If you are calling them soft based on reviewing on the M9's very poor lcd screen, you are in the same boat at many of us new M9 (and former M8) owners who were terribly worried the M9 was broken, until we saw how sharp (maybe even sharper than the M8) the actual images were when properly viewed in LR or Capture One. Link to post Share on other sites More sharing options...
ho_co Posted February 19, 2011 Share #9 Posted February 19, 2011 There's no reason that a lens should behave differently between M8 and M9. It's the same lens and will make the same image. The advantage actually goes to the M9's larger sensor. It requires less magnification to get to the same size result, which fact results in slightly more depth of field. Your M9's rangefinder may be off. The best way to test is normally wide open, since that reduces depth of field and makes the point of focus stand out. Could you post a sample or two? Link to post Share on other sites More sharing options...
Erik Gunst Lund Posted February 19, 2011 Share #10 Posted February 19, 2011 Hi and welcome Renapearl. As with your M8, the aperture information in the exif data is an estimate only.... The principle was patented back in 2006 Although it wasn't a US patent until Oct. 15. 2009 DIAPHRAGM VALUE RECOGNITION US 2009/0256954 A method for determining the current camera aperture (working aperture) of lenses on digital cameras having a viewfinder eyepiece and internal exposure measurement through the lens is wherein a further external exposure measurement is carried out past the lens and the value of the working aperture is determined from a reference table stored in the digital camera from the difference Delta BV between the two measured exposure values BV(int) and BV(ext). I have found it to be very accurate, much better than I initially thought possible Link to post Share on other sites More sharing options...
cbretteville Posted February 19, 2011 Share #11 Posted February 19, 2011 If you want to geek out completely, read the report I wrote on the metadata in the M8's files. It contains a rather comprehencive section on the G-Stop (guestimated aperture). The M9 uses the same technique so the statistics that I showed for the M8 should apply for the M9 too. The report is the basis for the metadata work Sandy did in Cornerfix and subsequently Adobe in Lightroom and Phil Harvey i ExifTool. You find it through the link in my sig. Carl Link to post Share on other sites More sharing options...
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