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Author Topic: 5dm3 - FPS Drops when battery below 50%  (Read 9051 times)

Skulker

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Re: 5dm3 - FPS Drops when battery below 50%
« Reply #30 on: May 29, 2013, 02:31:12 AM »

If you cared to read my full post instead of choking on the first sentence where I said I didn't buy your explanation, maybe you would have understood the point I was trying to make.

I wasn't saying that the slowing doesn't happen, I was just trying to figure out what is happening inside the camera to cause it. And I was saying that in cell phone world not using a regulator would be bad (actually impossible) design, and I was wondering if camera could work without one.

So you though it'd be funny to make sarcastic remark that if I'm so clever I should go help Canon design better cameras. Real funny.

Actually English is my second language, Swedish third, German fourth and Japanese fifth. Also took some studies in other languages, (in descending order of skills) Korean, Spanish, Chinese and French.

So sometimes I need to write it bit longer so I don't get misunderstood. But still I can't help it if someone deliberately skips the points I make and hangs on to the few sentences they wanted to misunderstand.

Thanks for another explanation and there was me with no idea that I was choking on your wise words. It's very good of you to help me. Also thanks for telling me that you never said what I never said that you said. I'm sure you were not trying to put words in my mouth.

Also thanks for explaining that English is your second language, that's pretty obvious. But I only mentioned it to point out it was irrelevant in reply to someone else, I never commented on your language skills. But it is so interesting to find you are a skilled multi linguist as well as a talented engineer.
If you debate with a fool onlookers can find it VERY difficult to tell the difference.

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Re: 5dm3 - FPS Drops when battery below 50%
« Reply #30 on: May 29, 2013, 02:31:12 AM »

luciolepri

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Re: 5dm3 - FPS Drops when battery below 50%
« Reply #31 on: May 29, 2013, 08:54:48 AM »
Not sure what the manual says about that one.

Don't know it myself, I just trust what others wrote....

dlleno

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Re: 5dm3 - FPS Drops when battery below 50%
« Reply #32 on: May 29, 2013, 10:07:53 AM »
I think you guys are missing the point trying to explain this in terms of energy available from the battery.  The battery has enough available energy -- this is happening  because the firmware is forcing a lower fps.  I suppose this is an attempt to conserve energy I don't know, but I doubt this has been programmed because of insufficient power to move the mirror and activate the shutter. 

btw the manual can be found here:
  http://www.usa.canon.com/cusa/consumer/products/cameras/slr_cameras/eos_5d_mark_iii#BrochuresAndManuals

top of page 114, at the end of the "selecting the drive mode" section:  "When the battery level is low, the continuous shooting speed may become slightly lower"

luciolepri

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Re: 5dm3 - FPS Drops when battery below 50%
« Reply #33 on: May 29, 2013, 10:58:40 AM »
"When the battery level is low, the continuous shooting speed may become slightly lower"

This makes perfect sense, to me. That's why I don't think that an evident frame drop when the battery is only at 50% should be considered "normal". On the other hand, I'd consider "normal" if the frame rate slighlty drops when the battery is at 10%. Maybe it also depens on the lens used, if it has IS or not and things like that.

dlleno

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Re: 5dm3 - FPS Drops when battery below 50%
« Reply #34 on: May 29, 2013, 11:05:36 AM »
"When the battery level is low, the continuous shooting speed may become slightly lower"

This makes perfect sense, to me. That's why I don't think that an evident frame drop when the battery is only at 50% should be considered "normal". On the other hand, I'd consider "normal" if the frame rate slighlty drops when the battery is at 10%. Maybe it also depens on the lens used, if it has IS or not and things like that.

True -- my opinion here is that reason this is happening is because  the firmware decision-making could be complex,. considering other factors besides the exact level of charge reported by the battery which, by the way, can be different for after-market batteries.  Also, I think the manual is poorly written and may not be trusted to describe what is actually happening... :D

East Wind Photography

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Re: 5dm3 - FPS Drops when battery below 50%
« Reply #35 on: May 29, 2013, 11:47:39 AM »
Postulating just for thoughts on how battery voltage can affect drive speed...and without knowing all of the facts this may or not be a possibility....

The battery is tied directly to the lens AF motor.  depending on the lens used may put more of a load on the battery and affect the AF speed of the lens.  If you have your camera firmware to 1st and 2nd shot focus priority, you could get yourself into a situation where slow AF can also slow your drive speed.

If you can reproduce the problem, please go into firmware and set 1st and 2nd shot priority to shutter priority and see if the speed picks up.  If so then you can say that AF speed may be the likely culprit. 



dlleno

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Re: 5dm3 - FPS Drops when battery below 50%
« Reply #36 on: May 29, 2013, 12:03:38 PM »
Postulating just for thoughts on how battery voltage can affect drive speed...and without knowing all of the facts this may or not be a possibility....

The battery is tied directly to the lens AF motor.  depending on the lens used may put more of a load on the battery and affect the AF speed of the lens.  If you have your camera firmware to 1st and 2nd shot focus priority, you could get yourself into a situation where slow AF can also slow your drive speed.

If you can reproduce the problem, please go into firmware and set 1st and 2nd shot priority to shutter priority and see if the speed picks up.  If so then you can say that AF speed may be the likely culprit.

or turn AF switch (on the lens) off.  The battery also powers IS, so turn that off as well.  Li batteries have very low internal resistance, so I really don't think this (by itself) is enough to explain the marked decrease in burst speed.  All these factors may be consistent with what I believe to be an unfortunately vague statement in the manual, i.e. if this was about battery behavior you might see 5.5fps instead of 6, which would occur at low battery levels, but it would not occur magically at 49%. 

I still think we have to think of this in terms of firmware behavior, not battery behavior.  The firmware's objective appears to be conservation of energy and prioritization of certain features like AF and IS ,which is may deem more important than burst speed. 


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Re: 5dm3 - FPS Drops when battery below 50%
« Reply #36 on: May 29, 2013, 12:03:38 PM »

East Wind Photography

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Re: 5dm3 - FPS Drops when battery below 50%
« Reply #37 on: May 29, 2013, 12:24:48 PM »
I dont agree with it being a firmware issue as I have used my 5DIII with and without a grip and run the batteries down to where the icon blinks and all functions stop.  I've never had it slow down in drive mode except when the camera has focus priority set or if one of the CPU intensive functions are enabled such as HTP or high ISO noise reduction.

I am more inclined to think that the problem is tied either to bad or slow AF motor and/or settings within the firmware to prioritize focus before taking the shot...not a defect but how the camera is supposed to work in those situations.

However re-creating the problem and disabling all of the firmware priority and software functions can help do determine if it's firmware or not.


Postulating just for thoughts on how battery voltage can affect drive speed...and without knowing all of the facts this may or not be a possibility....

The battery is tied directly to the lens AF motor.  depending on the lens used may put more of a load on the battery and affect the AF speed of the lens.  If you have your camera firmware to 1st and 2nd shot focus priority, you could get yourself into a situation where slow AF can also slow your drive speed.

If you can reproduce the problem, please go into firmware and set 1st and 2nd shot priority to shutter priority and see if the speed picks up.  If so then you can say that AF speed may be the likely culprit.

or turn AF switch (on the lens) off.  The battery also powers IS, so turn that off as well.  Li batteries have very low internal resistance, so I really don't think this (by itself) is enough to explain the marked decrease in burst speed.  All these factors may be consistent with what I believe to be an unfortunately vague statement in the manual, i.e. if this was about battery behavior you might see 5.5fps instead of 6, which would occur at low battery levels, but it would not occur magically at 49%. 

I still think we have to think of this in terms of firmware behavior, not battery behavior.  The firmware's objective appears to be conservation of energy and prioritization of certain features like AF and IS ,which is may deem more important than burst speed.

dlleno

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Re: 5dm3 - FPS Drops when battery below 50%
« Reply #38 on: May 29, 2013, 12:58:36 PM »
hmm.... ok good point East Wind and also very different than what the OP mentions and different from what has been reported out on the canon forum.  assume from your description that you using 100% genuine Canon batts too. 

part of the problem here is that Canon is woefully unclear as to the precise expected  behavior. that said, something is causing some cameras to magically change burst behavior at 49% battery level.

tpatana

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Re: 5dm3 - FPS Drops when battery below 50%
« Reply #39 on: May 29, 2013, 01:11:12 PM »
Can someone who sees the slow down happening, confirm if they are using OEM or 3rd party batteries? Like me and couple others mentioned, the battery voltage level doesn't drop much until the battery is really close to 0%, the 50% mark shouldn't be any reasonable limit to start slowing down stuff. Also power(/current) delivery stays good until almost drained empty. That's why it would make sense it's FW decision to start slowing down, instead of the battery directly causing it. But if not everyone sees it, I wonder if there's other factors affecting the speed.

East Wind Photography

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Re: 5dm3 - FPS Drops when battery below 50%
« Reply #40 on: May 29, 2013, 02:19:33 PM »
Yes I always use genuine Canon batteries as I get more shots per charge using them as well as longer general life expectancy.  In the long run it's less expensive...but that's not relevant to this discussion. 

Most definitely though a non-canon battery could directly affect AF speed as the lenses pull their power for AF directly from the battery.  Any anomaly there would slow down drive speed IF 1st and/or 2nd shot priority is set to AF.

Now not to say that there is some other issue, I just brought it up as it's a common condition most people set and forget.

hmm.... ok good point East Wind and also very different than what the OP mentions and different from what has been reported out on the canon forum.  assume from your description that you using 100% genuine Canon batts too. 

part of the problem here is that Canon is woefully unclear as to the precise expected  behavior. that said, something is causing some cameras to magically change burst behavior at 49% battery level.

phoizen

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Re: 5dm3 - FPS Drops when battery below 50%
« Reply #41 on: May 29, 2013, 03:46:36 PM »
Not sure what the manual says about that one.

Don't know it myself, I just trust what others wrote....

Actually more often than not, the manual doesn't give you the best explanation. I think this issue has pretty much proven that so. But thanks for that helpful tidbit.

I only use Canon batteries and it's happening to me. My testing over the past few days has shown that the problem is inconsistent using different camera bodies, and AA batteries in the grip. Regardless of that, if the manual states an fps drop is normal with low battery charge...they consider 49% to be low? That's odd.


dlleno

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Re: 5dm3 - FPS Drops when battery below 50%
« Reply #42 on: May 29, 2013, 04:01:15 PM »
Not sure what the manual says about that one.

Don't know it myself, I just trust what others wrote....

Actually more often than not, the manual doesn't give you the best explanation. I think this issue has pretty much proven that so. But thanks for that helpful tidbit.

I only use Canon batteries and it's happening to me. My testing over the past few days has shown that the problem is inconsistent using different camera bodies, and AA batteries in the grip. Regardless of that, if the manual states an fps drop is normal with low battery charge...they consider 49% to be low? That's odd.

There appears to be at least two problem descriptions being articulated. First,  the magic 49% onset of burst speed degredation has to be firmware related.  unless someone can convince me that the battery's internal resistance suddenly jumps over a cliff at that point.  to the extent that firmware is involved, and makes decisions based on the charge level reported by the battery, then yes I  believe the use of third party batteries should be part of the discussion.  In any case, it appears that firmware is making priority decisions based on a number of factors not altogether known, causing behavior that is hard to understand. 

the other problem discription is a more physically explainable scenario where things slow down when the battery gets tired under heavy demand.   This fits more consistently with the manuals horribly vauge disclaimer that keeps Canon from holding themselves responsible to clearly state the expected behavior. 

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Re: 5dm3 - FPS Drops when battery below 50%
« Reply #42 on: May 29, 2013, 04:01:15 PM »