marknorton Posted March 12, 2009 Author Share #21 Posted March 12, 2009 Advertisement (gone after registration) Andy, these tests were done using the old Anatomy workhorse and I'm waiting to send my other two back for upgrading (I have to work out when Week 12 is, soon I think); after that I'll be able to do a test. It's certainly interesting to be able to isolate just the shutter cocking using the discreet mode. As you suggest, we'll expect to see that peak reduced because of the reduced force required. It's interesting that the energy required to cock the shutter (the red area below) is a small fraction of the total energy used, so any ideas that a manual wind would lead to a greatly improved battery life are wrong. The current may be highest during the motor wind but it's only for a short period. 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! Quote 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/79157-anatomy-of-the-leica-m8s-power-consumption/?do=findComment&comment=837741'>More sharing options...
Advertisement Posted March 12, 2009 Posted March 12, 2009 Hi marknorton, Take a look here Anatomy of the Leica M8's Power Consumption. I'm sure you'll find what you were looking for!
adan Posted March 12, 2009 Share #22 Posted March 12, 2009 "...so any ideas that a manual wind would lead to a greatly improved battery life are wrong. " But Mark, you don't understand. The idea is to hook the manual wind lever to a little internal generator like the old field telephones...whizzz...whizzz...whizzz! Five strokes generates enough amps for one exposure. 8^) Quote Link to post Share on other sites More sharing options...
marknorton Posted March 12, 2009 Author Share #23 Posted March 12, 2009 Hah, I think it would take more than 5 strokes... good exercise for your thumb, though. Roughly, looking at the graph above, the total area under the graph is about 10 rectangles and each one represents 0.5 A flowing for 1 second. The total energy used is about 21 Joules (4.2 * 0.5 * 10) which, averaged over the idle to idle time of about 7 seconds is about 3 Watts, say, 1/20 of a typical domestic light bulb. Interesting too to think about that idling consumption of 200mA. If you don't have auto-power off configured, how much does it cost to wander around for an hour with the camera on? Answer: 4.2 * 3600 * 0.2 Joules = 144 image captures as above Even if you do have auto-power off set to 2 minutes, how many image captures do you lose by not switching the camera off immediately each time the camera waits to power off? Answer: 4.2 * 120 * 0.2 Joules = 4.8 image captures Quote Link to post Share on other sites More sharing options...
marknorton Posted March 12, 2009 Author Share #24 Posted March 12, 2009 For those of you who think this is a pointless excercise, here is your survival guide if you arrive at your destination of a lifetime with only one battery... 1. Shoot DNG, not JPEG 2. If you use discreet mode, wind on before the red LED stops flashing 3. Power off the camera if you don't expect to use it for 2 minutes - powering it off after every exposure is not recommended because there's a certain overhead in waking the camera up. 4. If the release timing is not critical, frame and focus before you touch the shutter release, then wake the camera and take your shot. 5. Don't use Auto-Review. 1 Quote Link to post Share on other sites More sharing options...
delander † Posted March 12, 2009 Share #25 Posted March 12, 2009 Great 'anatomy' Mark. It clearly shows why there appears to be such a variation among M8 users regarding battery life. Its not necessarily the batteries but the way the camera is set up and used. It will help us all get the most from the batteries. One would think that Leica would put this info into the manual somewhere, not all these 'scope displays but the overall advice on battery life. Jeff Quote Link to post Share on other sites More sharing options...
dpattinson Posted March 12, 2009 Share #26 Posted March 12, 2009 "when the menu is dismissed, there's additional work, probably writing the menu contents away to flash memory." Mark, I don't believe the camera writes settings back to persistent memory when they are changed. The reason is that on my camera at least, settings revert when the camera 'dies' and needs a battery eject. I think that the settings are only persisted during a normal power down of the camera (ie - when the power just be switch is moved to off). Of course - this could just be a camera specific issue with my camera. I guess you might be able to test this theory given your setup? Quote Link to post Share on other sites More sharing options...
marknorton Posted March 12, 2009 Author Share #27 Posted March 12, 2009 Advertisement (gone after registration) Yes, I think you are correct. Haven't noticed that before. In computing terms, the amount of data that's established by the SET and MENU options is tiny. Depending on what Manual WB requires, 32 bytes would probably do it, so I don't know why they don't commit it to flash RAM immediately. It used to be the case that flash RAM had a limited number of write cycles but I'm not sure that's an issue now. Maybe Leica thought the camera would never crash when they designed it... Quote Link to post Share on other sites More sharing options...
papimuzo Posted March 12, 2009 Share #28 Posted March 12, 2009 Mark, splendid analysis, very informative. Thanks. About the - large - spike when first switching on, it could well have "eroded" T2 upto death; do you think Leica damped the spike more or protected T2 via a protector? Quote Link to post Share on other sites More sharing options...
marknorton Posted March 12, 2009 Author Share #29 Posted March 12, 2009 Impossible to know really but although the spike is quite large, there's not much energy in it, so some sort of protection device - a zener or protection diode or a ferrite bead - could have been used. It's interesting that 2 out of my 3 cameras no longer wake up when you turn them on, you have to press the shutter release, so something has failed in them. Quote Link to post Share on other sites More sharing options...
farnz Posted March 12, 2009 Share #30 Posted March 12, 2009 Mark, Another clear and well-structured analysis. Thanks! With respect to the turn-on spike, do you think it indicates that the M8 presents a capacitive load to its input, which would account for the initial high current surge needed to fill the CR 'well'? It makes sense to me for it to be capacitive to prevent gradual battery drain while the M8's switched off. I presume that the remainder of the current draw is needed to complete a self-test routine and power the frame counter display, and the back porch looks like it may power the short burst of the LED. Pete. Quote Link to post Share on other sites More sharing options...
marknorton Posted March 12, 2009 Author Share #31 Posted March 12, 2009 Pete, impossible to say without a detailed understanding of the power supply arrangements but there's a switching power supply on the shutter controller flex print and it may be related to starting that, not sure! I don't think we should read too much into this, it was just speculation on my part| Quote Link to post Share on other sites More sharing options...
Shootist Posted March 12, 2009 Share #32 Posted March 12, 2009 Impossible to know really but although the spike is quite large, there's not much energy in it, so some sort of protection device - a zener or protection diode or a ferrite bead - could have been used. It's interesting that 2 out of my 3 cameras no longer wake up when you turn them on, you have to press the shutter release, so something has failed in them. Mark could the spike be caused by the meter coming on at turn on. That has to draw some power over and above the the normal POST the camera does. Quote Link to post Share on other sites More sharing options...
marknorton Posted March 12, 2009 Author Share #33 Posted March 12, 2009 Ed, as I said, it's difficult to know. It's a short-lived transient but I doubt it's anything to do with the light meter. Quote Link to post Share on other sites More sharing options...
Ario Arioldi Posted March 12, 2009 Share #34 Posted March 12, 2009 Thank you Mark, very interesting analysis. Does the peak current absorption take place only at switching on or there is a similar peak when waking-up from idle e.g. just pressing the shutter button? Ario Quote Link to post Share on other sites More sharing options...
diogenis Posted March 13, 2009 Share #35 Posted March 13, 2009 Great article Mark! You really put your new tektronix to good work! Results shown clearly indicate a permaban (unless needed ofcourse) towards jpegs: not only power hungry, but very time consuming as well. I am also very happy with how the new firmware transformed the camera: even though in theory, sound is the same in reality(psychological reasons?), separating the two while sooting in discrete does make a difference. Last, I am also surprised that this sapphire glass does make so much difference on this camera Anyway, great work there Quote Link to post Share on other sites More sharing options...
marknorton Posted March 13, 2009 Author Share #36 Posted March 13, 2009 Yes, the Tektronix is great (MSO2000 Mixed Signal Oscilloscope Series > Products : Tektronix), I'm using the MSO2024 with ethernet connection - you can capture the screen images via a web connection. Quite a daunting product to use out of the box - so many buttons, so many menus! Thank you all for your comments, I realise this is a more rarified thread but I hope the message is clear as to how to optimise your battery life. As for the M8, I'm looking forwards to having mine re-worked and upgraded. It's clear the camera has come some way since first launch, I've been busy removing the camera leather cover (not easy) in preparation for the trip to Solms. Quote Link to post Share on other sites More sharing options...
diogenis Posted March 13, 2009 Share #37 Posted March 13, 2009 You know what? I have been thinking, how you managed to take out these pictures you showed us. I didn't looked at the osc. of course, but I thought something using lan, or wifi... Quite a step up from the old oscilloscopes I was used to some 20 years back! Quote Link to post Share on other sites More sharing options...
Philinflash Posted March 13, 2009 Share #38 Posted March 13, 2009 Thanks very much, Mark, for delving into this subject. Your illustrations are clear and the explanations are useful and thoughtful. This very well answers the query I posed on March 6th about Discreet mode power consumption. Philip Kozloff Quote Link to post Share on other sites More sharing options...
marknorton Posted March 13, 2009 Author Share #39 Posted March 13, 2009 You know what? I have been thinking, how you managed to take out these pictures you showed us. I didn't looked at the osc. of course, but I thought something using lan, or wifi... Quite a step up from the old oscilloscopes I was used to some 20 years back! Yes, it sits alongside my venerable Tektronix 2246 which dates from 1990 and which I still use for analog work. Out of calibration now but still excellent. With the new one, you just connect using Internet Explorer to grab the images, into Photoshop for re-sizing ast .BMPs and save as JPEGs. It's interesting to see how 'scope technology has changed over 20 years! I also have a Heathkit scope I built in the 60's when I was 12 years old... Quote Link to post Share on other sites More sharing options...
farnz Posted March 13, 2009 Share #40 Posted March 13, 2009 ... I also have a Heathkit scope I built in the 60's when I was 12 years old... Impressive. I don't think I even knew what an oscilloscope was when I was 12 years old let alone trying to build one! (On the other hand, if you'd have asked me about the characters in Beano I'd have been in my element. ) Pete. Quote Link to post Share on other sites More sharing options...
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