BMCC interal time clock delays

Hi all,

got my BMCC in February and have been shooting with it after some weeks of testing on an actual job in the last two weeks.
Results are really amazing and my clients are very happy

After having the camera sit in its pelicase for 10 days or so (battery was full) I came across a strange delay of the interal time clock. It was almost 3 hours behind the correct time. When this got my attention I remembered having to re-adjust the time before the last shooting in May because the clock was off several days (since February when I first set the time of the clock).

So I would like to know if any other user has experienced the same clock delay?

That's a pretty hefty slippage. Was anything ever mentioned about jamming timecode from other devices in order to achieve TC sync? Just throwing that out there...

Yeah I've experienced the same. If there camera is off (battery fully charged) for several days. The time and or date will need to be adjusted..

Good that I am not the only one - I was beginning to think that it's just an accident.
After being away from home for 10 days, yesterday (May, 29th) I had a job done with my BMCC.
That's when I realized the camera's clock has been off several days! On 13:10, May 29 the BMCC showed
a time and date of 2013 - 05 - 24, 22:54. I mean, c'mon!
I had readjusted the clock before I left for my journey so it took the camera about 10 days to be 5+ days off! This is definitely not acceptable.

Hi Robert,
same problem here! I've experienced the same.My camera was couple of day off!

Cheers,

Milen

[Kristian Lam]

There is a supercapacitor that keeps the internal clock of the camera going. This supercapacitor is charged the battery when the camera is powered up. The battery does not power the internal clock directly so if the camera is left switched off for an extended period of time , the clock will not be accurate, even if the battery is fully charged.

Your best bet is to ensure your camera internal clock is synchronised by plugging it into your host computer over USB and running the Blackmagic Camera Utility. This will automatically synchronise the camera internal clock.

If this isn't mentioned in the manual, what about including it by now??

Thank you Kristian for clarifying this!

If this isn't mentioned in the manual, what about including it by now??

Just saw yesterday when re-reading the manual, that it is actually mentioned there - at least in the April 2013 version of the manual.

Thanks Kristian

When editing in the week I had noticed my date and time info on my footage from a shoot on Monday was way out. I just thought perhaps I have changed it by accident when setting up to shoot.

Good info. Worth including in the next manual update.

Adam - it is already in the manual.
I am not very happy with the way the clock works - the last thing I want to remember before shooting is checking time and date - there are a lot more important things I have to keep in mind and check on set when stress level is high enough already.

I always wonder how many users never even touched their manuals.

A lot of the questions asked here and on other forums over and over, are covered in the manuals or in the readme of the software/firmware updates for the BMC and other BM products.

I always wonder how many users never even touched their manuals.

A lot of the questions asked here and on other forums over and over, are covered in the manuals or in the readme of the software/firmware updates for the BMC and other BM products.

I think most people read the manual, but we're all guilty of skim reading that which we think we know. The operation of a clock on a camera is a basic funcion and one which we're all familiar with based on the plethora of electronic products with an internal clock we own. This is the only one I've heard of that slides out of sync after a few days of being off - but then again my mobile phone might do that if I left it off for that long. Who knows.

There is a supercapacitor that keeps the internal clock of the camera going. This supercapacitor is charged the battery when the camera is powered up. The battery does not power the internal clock directly so if the camera is left switched off for an extended period of time , the clock will not be accurate, even if the battery is fully charged.

Your best bet is to ensure your camera internal clock is synchronised by plugging it into your host computer over USB and running the Blackmagic Camera Utility. This will automatically synchronise the camera internal clock.

While we are on the topic of batteries, I noticed that there is no indicator when the power is off as to if the battery is fully charged or not. Just wondering if that is something that will be introduced later?

This very frustrating, especially when using time for timecode for sync... with all of the Cinema Pocket 6K Pro cameras we have.
Today I even noticed the time jumped in the future to 2022/11/01!

You guys think this is a bug or just engineer mistake?

This very frustrating, especially when using time for timecode for sync... with all of the Cinema Pocket 6K Pro cameras we have.
Today I even noticed the time jumped in the future to 2022/11/01!

You guys think this is a bug or just engineer mistake?

The answer is in this post upthread: viewtopic.php?f=2&t=7960#p54921

It's not a mistake, it's the way these cameras were designed. You have to reset the date and time before every shoot, it's just part of the routine although obviously a pain if you forget. I've trained myself to reset date and time whenever I put a battery in/on the camera and power it up. It's easy to do with the Pockets, much more laborious with the Micro Cinema Camera, which is what I mainly use. You can plug it into a computer to automatically set the date and time, but I have a baseplate attached to my BMMCC that blocks access to the USB port so I have to set date and time by hand, which requires a few minutes of pressing the tiny buttons and cursing.

Blackmagic camera and the adequacy of the clock display and battery, there is from the beginning not as it should be.
How can the time go in the future in the off state? I do not understand this at all.
Not a single device that has internal clock does this, only Blackmagic Camera.
A special Blackmagic feature.

Blackmagic camera and the adequacy of the clock display and battery, there is from the beginning not as it should be.

Somewhere in this forum I remember seeing a discussion about why BMD went with this approach. My memory of the argument was this: Unlike stills photographers and people using videocams, most cinematographers don't leave batteries in/on their cameras after a shoot. Because of that, BMD couldn't rely on the camera's battery to trickle-charge an internal battery that could be used to maintain time over longer periods when a cinema camera might be idle between jobs; I also think the decision to use the supercapacitor was to avoid the need to have users replace a small internal clock battery in the future when it eventually expires.

Interesting philosophy… looking at RED, Arri, Canon and Sony cameras.


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If this isn't mentioned in the manual, what about including it by now??

Just saw yesterday when re-reading the manual, that it is actually mentioned there - at least in the April 2013 version of the manual.

My BMCC manual is from September 2018 and as far as I can see it's not mentioned there. So, did BM remove the hint in the 2018 manual?

I see the advantage of using a supercapacitor instead of an inbuilt battery which might get unusable 10+ years later. But I think it would be nice to get warned in the manual, preferably on page 57 where the "Date and Time" feature is explained.

What does the supercapacitor actually do? Does it provide power to the digital clock circuitry -- or does the system measure the remaining voltage at the capacitor when the camera is turned on and then convert this analog voltage to a digital number (e.g. hours passed since 1/1/2010)?

Why do the other settings like function key assignments etc. remain intact when the camera is off for several days?

What does the supercapacitor actually do? Does it provide power to the digital clock circuitry -- or does the system measure the remaining voltage at the capacitor when the camera is turned on and then convert this analog voltage to a digital number (e.g. hours passed since 1/1/2010)?

Kristian Lam has explained it:

There is a supercapacitor that keeps the internal clock of the camera going. This supercapacitor is charged the battery when the camera is powered up. The battery does not power the internal clock directly so if the camera is left switched off for an extended period of time , the clock will not be accurate, even if the battery is fully charged.

Why do the other settings like function key assignments etc. remain intact when the camera is off for several days?

Because they are stored in a non-volatile memory and do not need power to remain intact.

I see. Vielen Dank.