wlaidlaw Posted January 28, 2014 Share #1 Posted January 28, 2014 Advertisement (gone after registration) Having recently seen some stunning starscapes that a friend took in Antarctica with a Phase One 645 and IQ180 back, I would like to try the same with my M240 and Noctilux. However as I read the manual, even if I use a cable release with a lock on it in shutter B mode, the shutter will trip shut after 60 seconds. Leica say this is to prevent image deterioration but I wonder if it is to prevent the CMOS sensor overheating and damaging itself. Am I correct and there is no way to expose for over 1 minute (the M 9 could manage considerably longer) and is there any way to get round the block? Would it be risky to the camera to try and circumvent the limitation? Wilson Link to post Share on other sites More sharing options...
Advertisement Posted January 28, 2014 Posted January 28, 2014 Hi wlaidlaw, Take a look here Long exposures on the M240. I'm sure you'll find what you were looking for!
jdlaing Posted January 29, 2014 Share #2 Posted January 29, 2014 Having recently seen some stunning starscapes that a friend took in Antarctica with a Phase One 645 and IQ180 back, I would like to try the same with my M240 and Noctilux. However as I read the manual, even if I use a cable release with a lock on it in shutter B mode, the shutter will trip shut after 60 seconds. Leica say this is to prevent image deterioration but I wonder if it is to prevent the CMOS sensor overheating and damaging itself. Am I correct and there is no way to expose for over 1 minute (the M 9 could manage considerably longer) and is there any way to get round the block? Would it be risky to the camera to try and circumvent the limitation? Wilson Yes it would be risky. The camera couldn't handle that very often without damage to the electronics package. Trust me. Link to post Share on other sites More sharing options...
colonel Posted January 30, 2014 Share #3 Posted January 30, 2014 What damage could arise to the camera ? Do you have any links ? Thanks Link to post Share on other sites More sharing options...
wlaidlaw Posted January 30, 2014 Author Share #4 Posted January 30, 2014 From my research, there appears on other makes of camera, to be no evidence of sensors overheating on long exposures. Here is a typical statement Re: sensor effects from very long exposures? From Canon's Tech guru Chuck Westfall: Long exposures pose no threat to the longevity of Canon's CMOS sensors in EOS Digital SLRs, but they will run the camera's battery down. If the battery voltage falls below a prescribed limit, the camera will shut off and any image data in the buffer memory will be lost. Are Leica just being over-cautious or is their something different about their “super thin” CMOS sensor? Wilson Link to post Share on other sites More sharing options...
luigi bertolotti Posted January 30, 2014 Share #5 Posted January 30, 2014 What damage could arise to the camera ?Do you have any links ? Thanks There is surely a good reason for limiting the exposure to 60 sec, otherwise they wouldn't have imposed it : when camera is in exposure mode with shutter open, all the circuitry around the sensor is powered : clearly, there is some component for which long power status is risky (probably, for overheating) ; it would be foolish to try to overcome this limitation, even if it is surely conservative and, probably, an exposure of 120-180 sec. , time to time and in no critical environment, would cause no damage... but they must consider that is a camera that can be used in any way one likes... a warning in the instructions of the kind "in case you take an exposure of 60 to 120 sec, external temperature must be less than 25°C and you must wait at least 1 minute to take another exposure... if the exposure is from 120 to 180 sec you must.. etc etc..." would be unacceptable.. after all, though costly, is a product for consumers, not a lab device... better to impose a straight limitation. Link to post Share on other sites More sharing options...
Guest JonathanP Posted January 30, 2014 Share #6 Posted January 30, 2014 I would think there's no overheating or damage issue - after all, the camera can record 30mins of video and AFAIK there is no limit on the live view time. Both video recording and live view are more likely to generate heat due to the continuos sensor read and reset cycles than one long exposure (essentially most of the power consumption in CMOS circuits is during state transitions). I suspect that Leica have placed the one minute limit based on a compromise between image quality (possibly thermal noise) and the maximum exposure that most users will need. So even if you could find a way around the limit, it may turn out to not be that useful. Jonathan Link to post Share on other sites More sharing options...
wlaidlaw Posted January 30, 2014 Author Share #7 Posted January 30, 2014 Advertisement (gone after registration) CMOS sensors are supposed to be lower noise than CCD due to lower thermal stress. I have certainly taken images with the M9 longer than one minute (4 minutes) and they worked just fine. I think a number of us are puzzled by this limitation. Wilson Link to post Share on other sites More sharing options...
wattsy Posted January 30, 2014 Share #8 Posted January 30, 2014 CMOS sensors are supposed to be lower noise than CCD due to lower thermal stress. I thought CMOS sensors are inherently more noisy than CCD but can create cleaner output due to on-chip processing? I think Jonathan is right, the limitation of 1 minute can't be to prevent damage if the same electronics can handle 30 minutes of video shooting, it must be because of noise/IQ considerations. Incidentally, how were you planning to circumvent the limitation, Wilson? Presumably the shutter will close after 60 seconds no matter what setting you are using. Link to post Share on other sites More sharing options...
wlaidlaw Posted January 30, 2014 Author Share #9 Posted January 30, 2014 I thought CMOS sensors are inherently more noisy than CCD but can create cleaner output due to on-chip processing? I think Jonathan is right, the limitation of 1 minute can't be to prevent damage if the same electronics can handle 30 minutes of video shooting, it must be because of noise/IQ considerations. Incidentally, how were you planning to circumvent the limitation, Wilson? Presumably the shutter will close after 60 seconds no matter what setting you are using. Ian, I was wondering if I could get round it by using one of the applications, which “talks” to the camera via the USB cable to the MF Grip e.g. Apple Image Capture, which allows the time lapse photography that Leica forgot to include in Image Shuttle. To see what can be achieved by much better photographers than me, have a look here: Long Exposure Photography: 15 Stunning Examples - Digital Photography School I think the forest and the lighthouse shots are particularly striking. I would for 99.99% of the time, be happy with the 4 minutes of the M9 but the 1 minute of the M240 is too short for creative work. Wilson Link to post Share on other sites More sharing options...
earleygallery Posted January 30, 2014 Share #10 Posted January 30, 2014 I guess you would have to take multiple exposures and make a composite image in PS. Link to post Share on other sites More sharing options...
wattsy Posted January 30, 2014 Share #11 Posted January 30, 2014 Do you not still have an M9 that you could use for these type of photos, Wilson? Just out of interest, what are the long exposure limitations on other CMOS cameras like those from Nikon and Canon? Presumably longer than the M240 , if the examples you link to are anything to go by. Link to post Share on other sites More sharing options...
colonel Posted January 30, 2014 Share #12 Posted January 30, 2014 There is surely a good reason for limiting the exposure to 60 sec, otherwise they wouldn't have imposed it : when camera is in exposure mode with shutter open, all the circuitry around the sensor is powered : clearly, there is some component for which long power status is risky (probably, for overheating) ; it would be foolish to try to overcome this limitation, . It would be nice to know the official Leica reason for the limitation. I am not complete sold on the heating point. I notice there is a camera error which says "PLEASE SWITCH OFF IMMEDIATELY" if you leave the sensor exposed for more then a few minutes for cleaning. Not sure if these are related. I was using a lamp close to the camera to provide good light to view the sensor, so it could also have heated the sensor but really clutching at straws as to the reason for the sensor exposed warning and also its link to the 60min shutter open max (e.g. too much light/heat potential for the sensor, which would obviously not be the case if it was astrological, but could be if you were shining a bright light at the sensor for more then 60 seconds ??) Link to post Share on other sites More sharing options...
wlaidlaw Posted January 30, 2014 Author Share #13 Posted January 30, 2014 Ian, On the Canon 5D Mk.3, you can certainly do 30 minute exposures but apparently they become a bit noisy. I would doubt there is any technical reason that the M240 could not take 4 minute exposures. I suspect it was just an arbitrary decision by the coders at Solms “oh that’s the longest anyone would want.” Wilson Link to post Share on other sites More sharing options...
Peter H Posted January 30, 2014 Share #14 Posted January 30, 2014 Wouldn't James' suggestion of layered multiple exposures give the advantage of longer exposures without the potential disadvantages, as well as being easy to do? Link to post Share on other sites More sharing options...
honcho Posted January 30, 2014 Share #15 Posted January 30, 2014 ......Just out of interest, what are the long exposure limitations on other CMOS cameras like those from Nikon and Canon? Presumably longer than the M240 , if the examples you link to are anything to go by. The longest exposure I have made on a Nikon D4 is 45 minutes, I don't know if there is any limit to long exposure. In-camera long exposure noise reduction processing takes about the same time as the actual exposure. The Fuji X-E2 (probably the new X-T1 also, just guessing) will make exposures of up to an hour. Only Phase One offer the MFD options for long exposures. Link to post Share on other sites More sharing options...
honcho Posted January 30, 2014 Share #16 Posted January 30, 2014 Exposure stacking could work on the M240, but with a long exposure limit of only 1 minute it would be a laborious exercise. Link to post Share on other sites More sharing options...
wlaidlaw Posted January 30, 2014 Author Share #17 Posted January 30, 2014 Wouldn't James' suggestion of layered multiple exposures give the advantage of longer exposures without the potential disadvantages, as well as being easy to do? Peter, I don’t see how that would work. If you have a number of dark exposures which are all under-exposed, how does adding them together in merge, improve the situation? Sure if you want to get movement, like a stream of car lights, I can see how it would work but not for very dark conditions. Wilson Link to post Share on other sites More sharing options...
xrogers Posted January 30, 2014 Share #18 Posted January 30, 2014 Star trails can appear in any nighttime photo with visible sky. You can't turn off dark frame subtraction on the M, so exposure stacking gives you a series of 1 minute exposures with 1 minute gaps between them, making your star trails into dotted lines. Yuck. Link to post Share on other sites More sharing options...
wlaidlaw Posted January 30, 2014 Author Share #19 Posted January 30, 2014 Do you not still have an M9 that you could use for these type of photos, Wilson? Just out of interest, what are the long exposure limitations on other CMOS cameras like those from Nikon and Canon? Presumably longer than the M240 , if the examples you link to are anything to go by. Ian, I am not taking the M9 with me to India but just the M240 in M bodies. I want to get some night sky photos with moonlit temples/palaces in the foreground. I don’t know what the B/T limit with my Olympus EP-5, which I am taking, is. I can always put the Noctilux on that, as I have a Metabones M to MFT adapter in my bag. The EP-5 has the advantage of a real time histogram, so that you terminate the exposure when you see that the right hand side is being reached. Wilson Link to post Share on other sites More sharing options...
jaques Posted January 30, 2014 Share #20 Posted January 30, 2014 Not only are you limited to 60 seconds- you can only get that at ISO 200. I wish Leica would just tell us why there is such a limitation an end speculation. If it is due to IQ concerns alone I wish they would let the user decide what is tolerable... If it is a heat issue I wonder why when other CMOS cameras can do it easily? I enjoyed taking long exposures over 120 seconds on the m9- the M240 is a big move backwards in this department:mad:. I also wish Leica (or anyone:rolleyes:) would tell me if dark frame exposure has to happen immediately after a shot is taken (and why)- or if it can be done later. It seems to me that if it could be done later that would be a huge boon: the user could select the option for batch dark frame subtraction to occur post shoot- effectively doubling possible exposures during a long night shoot... Link to post Share on other sites More sharing options...
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