greene881 Posted July 11, 2016 Share #1 Posted July 11, 2016 Advertisement (gone after registration) I have my M246 monochrom up for sale and had a request from an interested party. They have asked for a series of shots at various ISOs of a black background, they say they want to test for banding and any other [unspecified] issues. Can anyone enlighten me as to what they are looking for / what these test should show. They also wish to check the shutter count from the RAW file, is this possible from a 246. many thanks John Link to post Share on other sites More sharing options...
Advertisement Posted July 11, 2016 Posted July 11, 2016 Hi greene881, Take a look here M246 "banding test". I'm sure you'll find what you were looking for!
Giulio Zanni Posted July 11, 2016 Share #2 Posted July 11, 2016 I have my M246 monochrom up for sale and had a request from an interested party. They have asked for a series of shots at various ISOs of a black background, they say they want to test for banding and any other [unspecified] issues. Can anyone enlighten me as to what they are looking for / what these test should show. They also wish to check the shutter count from the RAW file, is this possible from a 246. many thanks John A black background at various ISOs would suggest that they want to see the level of noise and possible banding when lifting the shadows. Link to post Share on other sites More sharing options...
250swb Posted July 12, 2016 Share #3 Posted July 12, 2016 Checking the shutter count isn't possible, so I suggest they have been listening to whispers and misinformation, always a pain if the buyer is expecting too much. This may also be the case with 'banding' in which they may have higher expectations than what is reasonable. It suggests they may be a novice so be prepared to tell them they can't have it before they find faults where there are none. Steve Link to post Share on other sites More sharing options...
jaapv Posted July 12, 2016 Share #4 Posted July 12, 2016 I would be rather hesitant to sell a camera under these conditions. I would certainly have them sign an indemnity that this is a private sale without guaranty or returns. Link to post Share on other sites More sharing options...
Giulio Zanni Posted July 12, 2016 Share #5 Posted July 12, 2016 Asking for test shots when buying from a private a second hand high ticket canera might not be totally unreasonable Link to post Share on other sites More sharing options...
pechelman Posted July 12, 2016 Share #6 Posted July 12, 2016 just tell him the last number on the file. While that isnt an accurate way to determine shutter count, it's also not completely unreasonable if you are the original owner and have always reset your numbering after updating with firmware. regarding the banding, I also dont think it's unreasonable to provide *a few* pictures as requested. While I dont know what they're expecting, I'm imaging they just want to verify that there's no crazy horizontal or vertical banding or dead pixels or anything like that. What I'd say to do is just go into a dark closet or bathroom and shoot at ~3200, 6400, and 10000 and provide them with the images. Use a fast enough shutter speed to avoid having the 2nd noise image subtracted. Link to post Share on other sites More sharing options...
jaapv Posted July 12, 2016 Share #7 Posted July 12, 2016 Advertisement (gone after registration) Asking for test shots when buying from a private a second hand high ticket canera might not be totally unreasonable No it is certainly not, but it rather sets the tone. Reason why I will always sell on this forum to established members and accept a return within a reasonable period, say a week. Link to post Share on other sites More sharing options...
Belle123 Posted July 12, 2016 Share #8 Posted July 12, 2016 I would probably pass as the buyer doesn't sound familiar with the M or the M246. And being that the camera has only been out a year, the number of actuations should not be an issue. Link to post Share on other sites More sharing options...
pico Posted July 12, 2016 Share #9 Posted July 12, 2016 [...] It suggests they may be a novice so be prepared to tell them they can't have it before they find faults where there are none. I'm with Steve on this. Some time ago we witnessed a confused individual making a seller just miserable, demanding a return for a misunderstanding, nothing was wrong with the camera. I'd avoid this particular buyer. He can find his answers in so many places. Link to post Share on other sites More sharing options...
adan Posted July 12, 2016 Share #10 Posted July 12, 2016 Attached image shows what "banding" looks like - streaky horizontal sensor noise. M240, converted to B&W, ISO 6400 - "pushed" (brightened) extremely for demonstration purposes. (vertical crop from a horizontal original). Which just goes to show, one can find banding in almost any high-ISO image, if one tries hard enough... (my Monochrom v.1 shows faint bands without pushing at ISO 10000, none at 8000 without some manipulation) Digital M's output a "unique image ID" in EXIF, which is supposed to be the true number of actuations (shutter firings) in hexadecimal notation - but in the CMOS Ms it seems to be a nonsense number. I have three sequential pictures from an M240, that show "unique ID" numbers of - about 6000, about 1.1 million, and about 500000. Additionally, in any camera with live view and video capability, "actuations" themselves, as a measure of use, are mostly nonsense these days. Use "live view" or EVF 1000 times, without ever taking a picture, and you'll still record 1000 actuations. Shoot 20 minutes of video in one take, and that is significant use, that will get counted as only one actuation. But what the heck - send the prospective buyer a few images. Tell him you can't check exact actuations yourself (but give an estimate, if you can make a good guess of your history -1500, 6500, 24500). If he thinks he knows how to get a useful measure of actuations from the file data - good luck to him! Same for banding. Send correctly exposed DNG images at high ISOs under poor light, and let him hack at them to see what he sees. 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/262437-m246-banding-test/?do=findComment&comment=3077706'>More sharing options...
jaapv Posted July 12, 2016 Share #11 Posted July 12, 2016 Andy is right, banding shows up on underexposed images, regardless of ISO. Make sure you send mildly overexposed, never mind the highlights images. Link to post Share on other sites More sharing options...
250swb Posted July 13, 2016 Share #12 Posted July 13, 2016 Asking for test shots when buying from a private a second hand high ticket canera might not be totally unreasonable And what will you learn? Will you know if the rangefinder is inaccurate, the exposure made perfectly, the post processing optimal,....or are you looking at photographs made by a photographer with a low skill threshold? Just about the only thing you could tell from a supplied picture is if there are any hot pixels, and those could have been cloned out. You could perhaps tell if the camera has been looked after if there was any dust in the picture, but there will be dust on the sensor after being joggled around in the post on it's way to you, so it would need cleaning anyway. Link to post Share on other sites More sharing options...
Giulio Zanni Posted July 13, 2016 Share #13 Posted July 13, 2016 And what will you learn? Will you know if the rangefinder is inaccurate, the exposure made perfectly, the post processing optimal,....or are you looking at photographs made by a photographer with a low skill threshold? Just about the only thing you could tell from a supplied picture is if there are any hot pixels, and those could have been cloned out. You could perhaps tell if the camera has been looked after if there was any dust in the picture, but there will be dust on the sensor after being joggled around in the post on it's way to you, so it would need cleaning anyway. I think we are talking about raw files, not jpegs, and from a raw file you can learn a lot of things....among others, if you are not familiar with the camera, you might want to see how the file reacts in post-processing etc. etc. etc. Link to post Share on other sites More sharing options...
jaapv Posted July 14, 2016 Share #14 Posted July 14, 2016 Yes, but improving one's postprocessing skills by pretending to buy a camera is not a very nice way to go about it. If you want to see whether the output of a specific type of camera appeals there are other ways of obtaining DNG's Link to post Share on other sites More sharing options...
250swb Posted July 14, 2016 Share #15 Posted July 14, 2016 I think we are talking about raw files, not jpegs, and from a raw file you can learn a lot of things....among others, if you are not familiar with the camera, you might want to see how the file reacts in post-processing etc. etc. etc. Do you think that? I think if it comes to demanding .dng files that should definitely be the last straw. I've had potential buyers like that trying to sell a house, happy to tell you on their way out after a viewing that they only came to see what was available in this price range. There is so much information available for todays digital cameras (sample .dng files, tutorials, etc.) that it makes you realise how difficult it was to sell a film camera, having to shoot a roll of film and post it to the buyer to prove it works..............not. If you can't spot an awkward customer then you are your own worst enemy. Link to post Share on other sites More sharing options...
Giulio Zanni Posted July 14, 2016 Share #16 Posted July 14, 2016 Do you think that? I think if it comes to demanding .dng files that should definitely be the last straw. I've had potential buyers like that trying to sell a house, happy to tell you on their way out after a viewing that they only came to see what was available in this price range. There is so much information available for todays digital cameras (sample .dng files, tutorials, etc.) that it makes you realise how difficult it was to sell a film camera, having to shoot a roll of film and post it to the buyer to prove it works..............not. If you can't spot an awkward customer then you are your own worst enemy. Whatever, but I still think it was not an akward request Link to post Share on other sites More sharing options...
ralphh Posted July 14, 2016 Share #17 Posted July 14, 2016 Whatever, but I still think it was not an akward request I tend to agree. It is very hard to get someone to take something back on eBay, esp if the seller is convinced there's nothing wrong. This is a huge amount of cash to invest on a second hand item with potentially no recourse in the event of an issue. This guy might have saved every spare penny for years to buy this camera. Wanting to see that there are no hidden issues is not that bizarre. Would you buy a camera without seeing photos of it? Imagine if there was a M240 on ebay with no photos. I know I wouldn't. And yet how much more important is the photos that come out of a camera than photos of it?! I personally didn't think to ask for an image out of the camera when I bought mine, but now I think it's not a bad idea. I wouldn't be looking for the same things (unless I'd read whatever he's read that's got him worried), but just knowing that it's producing photos with no obvious issues is probably a wise move. Link to post Share on other sites More sharing options...
jaapv Posted July 14, 2016 Share #18 Posted July 14, 2016 I would not buy on eBay at all in that case; a reputed dealer is the way to go. Link to post Share on other sites More sharing options...
greene881 Posted July 21, 2016 Author Share #19 Posted July 21, 2016 Thank you all for your comments. By way of an update I provided the enquirer with five test raw files via Dropbox on 12 July. To date I have not received an acknowledgement, thanks or heard from him since, no surprise to some probably. Link to post Share on other sites More sharing options...
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