Bert N Posted July 27, 2010 Share #41 Posted July 27, 2010 Advertisement (gone after registration) Umm... wouldn't the hot pixels be mapped out by the standard black frame that the camera produces at long exposures? I don't think that this is true for the raw file. That's why the surface profile shows a large variation in signal intensity between the different pixels while the (corrected) jpg image is a uniform black frame. The correction is basically subtracting a dark frame of the same exposure time as the image frame which happens to be a dark frame in my test. Link to post Share on other sites More sharing options...
Advertisement Posted July 27, 2010 Posted July 27, 2010 Hi Bert N, Take a look here M8 doubts. I'm sure you'll find what you were looking for!
Bert N Posted July 27, 2010 Share #42 Posted July 27, 2010 Bert, Presuming that the Y-axis is luminance, the surface profile plot appears to show much higher average values of luminance than I'd expect to see. For example there seem to be a lot of values approaching 100 or so, which is clearly not 'black' in luminance terms. Is there a positive bias value included perhaps? Pete. Pete - The signal level of each pixel is shown in the y-axis, since the DNG conversion was 8 bits per channel, the levels range from 0 - 255. The average value looks normal to me since there is always signal due to dark current in a sensor (charge that is thermally generated in the silicon and subsequently captured in each pixel). There is also leakage current in the sensor that also contribute to the dark signal. Link to post Share on other sites More sharing options...
farnz Posted July 27, 2010 Share #43 Posted July 27, 2010 Pete - The signal level of each pixel is shown in the y-axis, since the DNG conversion was 8 bits per channel, the levels range from 0 - 255. The average value looks normal to me since there is always signal due to dark current in a sensor (charge that is thermally generated in the silicon and subsequently captured in each pixel). There is also leakage current in the sensor that also contribute to the dark signal. Thanks for the explanation, Bert. I idly thought that since it is a black screen the values would approach zero so it didn't look right. Pete. Link to post Share on other sites More sharing options...
menos I M6 Posted July 28, 2010 Share #44 Posted July 28, 2010 I'd reconsider the 35 Summarit choice, as a new lens is about the price range of nice second hand 35 Cron or (if you like the look) a pre ASPH 35 Summilux. Even a second hand 35 Summarit is not much cheaper and I would really consider other manufacturers, when looking for sole budged - the nice little CV 35 f2.5 pancake comes to mind with prices of around 200,- EUR used! Or even a new CV 35 f1.4 MC, which fairs in at around 400 − 440,- EUR with the slight soft look of the older Summilux. May the Summarit lens range be good as it is - price wise it does not compete, only, when it comes to the "it must be a Leica, it must be new and it must be affordable" credo. I considered a second hand 50 Summarit, while my 50 Lux is in Solms as a stop gap lens, it does do nice pictures, is sharp, compact and light, is coded for convenience, … it does still cost more than 500,- EUR though and say what you want - the sample I tried was feeling not as my other Leica lenses. It was smooth, yes, but at the same time felt slightly rough - hard, to pack in words. Link to post Share on other sites More sharing options...
jaapv Posted July 28, 2010 Share #45 Posted July 28, 2010 I don't think that this is true for the raw file. That's why the surface profile shows a large variation in signal intensity between the different pixels while the (corrected) jpg image is a uniform black frame. The correction is basically subtracting a dark frame of the same exposure time as the image frame which happens to be a dark frame in my test. No - the M8/ M9 takes a second "black" exposure to cancel out the hot pixels prior to the writing of the RAW on long exposures. Link to post Share on other sites More sharing options...
shootinglulu Posted July 28, 2010 Share #46 Posted July 28, 2010 The London camera exchange in Bristol had an ex demo 35 Summarit for sale yesterday. Link to post Share on other sites More sharing options...
Bert N Posted July 28, 2010 Share #47 Posted July 28, 2010 Advertisement (gone after registration) No - the M8/ M9 takes a second "black" exposure to cancel out the hot pixels prior to the writing of the RAW on long exposures. Where is this documented? I see a big difference between the jpg image and the raw frame. Below is a pixel level view of the raw image and a surface profile plot of the jpg image. There is a huge difference between the 2 files. Sorry Mark, for hijacking your thread, I won't say anymore on this subject... Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/126793-m8-doubts/?do=findComment&comment=1390468'>More sharing options...
jaapv Posted July 28, 2010 Share #48 Posted July 28, 2010 You don't need to document it - shoot DNG only and you will see that it is noisefree... You can see the change happening on your LCD too. Link to post Share on other sites More sharing options...
Julian Thompson Posted July 28, 2010 Share #49 Posted July 28, 2010 Get a 40mm Summicron C - you can pick one up for about £250 and it's a great little lens - also it makes the most compact M8 you can get, which is reason enough to own one! Link to post Share on other sites More sharing options...
pietjs Posted July 28, 2010 Share #50 Posted July 28, 2010 Just bought a superb used M8 only 2 days ago. Already absolutely in love with it. I thought it it be a steep learning curve to switch from an 'ordinary' SLR, but it is the best switch I ever made!! I know it's early days but I would really really recommend getting a well cared for used M8. If you go for new, you'd better save up and get the M9. For me the M8 is my camera for life! Link to post Share on other sites More sharing options...
jsrockit Posted July 29, 2010 Share #51 Posted July 29, 2010 Get a 40mm Summicron C - you can pick one up for about £250 and it's a great little lens - also it makes the most compact M8 you can get, which is reason enough to own one! Yes, but the framelines are just too damn inaccurate...unless you're a serial cropper. Link to post Share on other sites More sharing options...
Geno Posted July 29, 2010 Share #52 Posted July 29, 2010 Hi, I have ordered an M8, a new one, and would go this afternoon to fetch it. The price for a new one is 3000 Euro. After registration I'll have 3 years warranty, two free filters and of course the complete package. I like and dislike this forum; you get so confused by it. There seem to be so many issues with the M8 apart from the known issues with the UV and IR. It makes me doubt, 3000 Euro for the body is still a lot of money. Is it still a sensible thing to buy an M8 today? Please hit me with confirmation. I purchased a "new" M8.2 weeks ago, close to the 3,000 EUR you quote. One of the happiest days I have had in years. Filters have arrived, camera is flawless and the Billingham case protects it in transit and other lens/flash. M8/28mm spends most of the time over my neck or shoulder. Had a chance to shot hundreds of photos of old classmates over the weekend (Class of 1965), very happy with results even the interiior dance photos with SF-24d - does a nice natural TTL job. Glad you are happy too!!!! Link to post Share on other sites More sharing options...
jaapv Posted July 29, 2010 Share #53 Posted July 29, 2010 Yes, but the framelines are just too damn inaccurate...unless you're a serial cropper.Or gain the experience to judge the focussing shift they have.... Link to post Share on other sites More sharing options...
bocaburger Posted July 29, 2010 Share #54 Posted July 29, 2010 Or gain the experience to judge the focussing shift they have.... Too bad they couldn't incorporate that in the "S" mode Link to post Share on other sites More sharing options...
Julian Thompson Posted July 29, 2010 Share #55 Posted July 29, 2010 Yes, but the framelines are just too damn inaccurate...unless you're a serial cropper. I've not found it a problem - you quickly learn how far from the displayed framelines the actual image is. It's not ideal but certainly a nice little lens for the money - don't be put off! Link to post Share on other sites More sharing options...
Julian Thompson Posted July 29, 2010 Share #56 Posted July 29, 2010 Example shot of 40 bokeh/focus for you Mark, as discussed on PM. It's not as nice as the 35 summicron but then it's a) smaller and a whole lot cheaper ! Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/126793-m8-doubts/?do=findComment&comment=1391458'>More sharing options...
Julian Thompson Posted July 29, 2010 Share #57 Posted July 29, 2010 Ug that's a nasty jpeg - at least the bokeh is representative :-) Link to post Share on other sites More sharing options...
jsrockit Posted July 30, 2010 Share #58 Posted July 30, 2010 Or gain the experience to judge the focussing shift they have.... Yes, we all do that... but the original M8 is just stupidly inaccurate even on lenses that are matched to its framelines. The M8.2 is so much easier to deal with since it has only normal rangefinder inaccuracy. Link to post Share on other sites More sharing options...
Bert N Posted July 30, 2010 Share #59 Posted July 30, 2010 Yes, we all do that... but the original M8 is just stupidly inaccurate even on lenses that are matched to its framelines. The M8.2 is so much easier to deal with since it has only normal rangefinder inaccuracy. I actually don't have any issues with the M8 focus or framing accuracy, at least for now... Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/126793-m8-doubts/?do=findComment&comment=1391966'>More sharing options...
john_newell Posted July 30, 2010 Share #60 Posted July 30, 2010 Yes, we all do that... but the original M8 is just stupidly inaccurate even on lenses that are matched to its framelines. The M8.2 is so much easier to deal with since it has only normal rangefinder inaccuracy. Are you saying the M8 framelines are inaccurate, or that the M8 rangefinder is inaccurate? Link to post Share on other sites More sharing options...
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