Anatomy of the Leica M8's Power Consumption

[sean_reid]

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Fantastic work Mark - thanks for doing it.

 

Cheers,

 

Sean

[vertekijker]

Only now discovered this thread. So very helpful what Marc figured out for us! Thank you, thank you.

------------------

Frans

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[marknorton]

We are starting to get there, but it still looks to me that some component is not put to sleep as it should be when the camera is inactive.

 

The other area I think may be powered on all the time the camera is awake is the light meter. Given the EV 20 dynamic range it has to deal with, it might be quite difficult to get it stable in just a few tens of mS.

[dpattinson]

The other area I think may be powered on all the time the camera is awake is the light meter. Given the EV 20 dynamic range it has to deal with, it might be quite difficult to get it stable in just a few tens of mS.

 

Mine used to have issues when waking from passivation, would use the last reading taken before passivation rather than taking a new one. By passivation I mean where the viewfinder display has switched off, but the camera is still on. So I suspect there are indeed timing issues with waking the meter.

[marknorton]

Fantastic work Mark - thanks for doing it.

 

Thanks Sean (and Frans). Hopefully this thread might prevent some photographers losing that great shot because their battery has gone flat earlier than it needed to!

[steamboat]

NOW I understand my battery consumption when shooting DNG + (fine) JPG. Many thanks, Mark!

[mike prevette]

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Thanks Mark! I really appreciate your analysis.

 

_mike

[fefe]

The other area I think may be powered on all the time the camera is awake is the light meter. Given the EV 20 dynamic range it has to deal with, it might be quite difficult to get it stable in just a few tens of mS.

 

The lightmeters I have found data on are ~30mW active for 20EV range (Spectra cine models), even if it is on all the time it shouldn't be that much vs the total.

 

Adding the DSP, the ARM core, the M16C, and a lightmeter doesn't get us to half the idle power assuming the power management schemes available in these cores are used.

 

Figuring out the FPGA power is harder and might be the key. There are a few other sensors spread around the camera but these shouldn't consume that much even combined, remains the DRAM buffer.

[wparsonsgisnet]

I wanted to comment regarding the flip side of this coin.

 

First, it's a great thread. Many thanks, Mark.

 

Second, speed shooting -- which is my requirement to capture ballet in performance -- correlates exactly with low battery consumption. That is, the camera activities that consume power also use up clock time.

 

So, for shooting motion, one needs:

 

1. DNG only, for fastest write times,

2. No review, as this also takes clock time,

3. Standard shutter, as the delay from the quieter mode lengthens the time until the shutter is ready for a shot.

 

4. Finally, my druthers:

 

a. I wish that the Continuous mode worked better. It has a benefit in that although it must be consuming some battery power it allows for faster shooting if the light doesn't change. That is, the metering is 'done' before the shot. Unfortunately, whenever I use it, it always goes to the continuously flashing red light mode before too long. I am not holding down the shutter, just taking pictures rapidly, and the behavior goes south.

 

b. The buffer just isn't big enough for action shooting. This would have been a good candidate for the M8.x camera and it's a severe achilles' heel for Leica. This is "non-professional" in my view -- and has been carried on to the M9. Yes, the M9 buffer is bigger -- by about the increase in the damn file size. Is there no elbow room in the memory design?

 

c. It would be nice to be able to use the last 1/3 of the battery charge. My M8's always misbehave once the last segment of battery is showing.

 

But the to-do list for battery consumption works for speed shooting as well.

[Gerard]

Spot on with 'a' and 'b', Bill.

[Doc Henry]

It is a pleasure to read this thread and thank you Mark for giving us a mini course on the use of the M8.

Sincere thanks for this work.

 

However I have a question, just outside this topic

I would like to ask Mark

What do you think of generic batteries?

Does it deliver enough power to properly operate the M8

(sudden voltage drop?)

Here is the indirect response from Leica about this:

2.5 Rechargeable batteries of other makes are now being offered for the LEICA M8. Can I

use them without hesitation in my camera?

Tests with these batteries have revealed that they sometimes have considerably less capacity than

the original Leica battery 14 464 (e.g. 1400mAh instead of1900mAh as in the case of the original).

The other make battery is not equipped with the charging circuitry dedicated to the camera

electronics, therefore malfunctions may occur, such as a false indication of the remaining capacity,

or the camera may switch itself off suddenly and unexpectedly. Above all, the camera’s warranty

expires if malfunctioning is caused by the use of none-dedicated accessories (see warranty

conditions in the Warranty Card).

The mandatory protective measures for Li-ion batteries may be different from the original and

therefore insufficient in the case of these other make products. As a result, Leica will not accept

any liability concerning any damage caused by using these batteries, including damage occurring

during charging and transportation.

Thanks

Best regards

Henry