RAW fps override time lapse

Started by Doyle4, September 07, 2013, 06:41:02 PM

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Doyle4

Does anyone know if the camera heats up using fps override as much as shooting normal raw footage say? im expecting it too be much cooler than 24p but would like to double check before leaving the camera for few hours.

cheers,

SpcCb

Results depends of the camera model, and if you use low light FPSO or not (short frames).

But what I see is, with a 5D mkII, if you stay to a relatively high frame rate in FPSO the CMOS heat like in normal frame rate mode. You can see differences if you use low frame rate in FPSO & in low light mode, like 4s frame duration.

It's interesting in this config to switch off the LCD to minimised the CMOS heating.
And note it's better to use FPSO in low light mode when external temperature is low (<10°C) because the CMOS temperature is heating during a very long time before to be stable (couple of hours). So noise will increased through footage duration and it will be hard to clean.

zuzukasuma

Quote from: SpcCb on September 11, 2013, 11:22:53 AM
...FPSO in low light mode when external temperature is low (<10°C) because the CMOS temperature is heating during a very long time before to be stable (couple of hours). So noise will increased through footage duration and it will be hard to clean.


you're exactly right about that. I set up everything, calculated almost all aspects, connected batteries, emptied card and begin shooting, after 50 minutes noise started to occur, and impossible to get rid of it on EOS M. I've tried to hook up a CPU cooler with some peltier pad underneath but no luck. I'd like to see next EOS M has a copper cooling panel like Nex 7.
in a complicated relationship with eos m.

SpcCb

Indeed, the only way to get constant and low noise with long duration frames is to use a temperature stabilised cooling device, like we use in astronomy cameras.
And more the CMOS is big (24x36, etc.), more the temperature inertia is big.

Beside, you can find companies who propose modified camera with this kind of device. But it's not cheap...

zuzukasuma

Quote from: SpcCb on September 11, 2013, 01:16:43 PM
Indeed, the only way to get constant and low noise with long duration frames is to use a temperature stabilised cooling device, like we use in astronomy cameras.
And more the CMOS is big (24x36, etc.), more the temperature inertia is big.

Beside, you can find companies who propose modified camera with this kind of device. But it's not cheap...

maybe we can connect peltier's cold side directly to the magnesium alloy bodies?

I don't have one with completely magnesium alloy, but its worth to shot I think.
in a complicated relationship with eos m.

SpcCb

Quote from: zuzukasuma on September 11, 2013, 01:20:15 PM
maybe we can connect peltier's cold side directly to the magnesium alloy bodies?
(...)
It helps. When a 400f/2.8L is on the camera (or this inverse, question of weight ^.^) this lens _massive_ is 'cooling' the camera through the magnesium body. I ever noticed ~5°C less on the CMOS.
But it's not enough to be efficient: The cooling device has to be directly back on the CMOS, the thermal bridge between CMOS and body is to small.

zuzukasuma

Quote from: SpcCb on September 11, 2013, 01:39:42 PM
It helps. When a 400f/2.8L is on the camera (or this inverse, question of weight ^.^) this lens _massive_ is 'cooling' the camera through the magnesium body. I ever noticed ~5°C less on the CMOS.
But it's not enough to be efficient: The cooling device has to be directly back on the CMOS, the thermal bridge between CMOS and body is to small.

peltier can freeze cmos to death if you know what it is :))
in a complicated relationship with eos m.

Doyle4

This fps override is confusing me lol, i have learning difficulties so im sorry if i ask too many questions or repeat my self.

But could you explain to me what each mode does if possible? im mainly wanting to do day time ones, or do you think its best if i just use my shutter instead to keep cooling down etc?

Cheers

zuzukasuma

on the movie tab you can adjust fps override option, from 0.2 (on eos m min 0.455 to 35 possible) to 65 frames, there is a video in the forum, he used 48fps 1080p RAW on 5D Mark III, looks nice. if you'd like to shoot a timelapse or sth else you must click to advanced tab to adjust shutter speeds for your needs, I'm using mostly 25fps with 1/40 to 1/1600 option for RAW video and 1fps for timelapse 1/1 to 1/15 with ND filter
in a complicated relationship with eos m.

a1ex

Quote from: Doyle4 on September 11, 2013, 07:08:38 PM
But could you explain to me what each mode does

Ever tried to read the user guide, or the bottom help text in ML menu? They are described in detail there.

SpcCb

Quote from: zuzukasuma on September 11, 2013, 01:43:36 PM
peltier can freeze cmos to death if you know what it is :))
I know, I use triple stages Peltier to cool low flux cameras ;)
(Delta T ~40°C below the ambient temp is usual for me)

But the stability is also important.
With the thermal bridge body/CMOS there's no way...

zuzukasuma

Quote from: SpcCb on September 11, 2013, 11:39:23 PM
I know, I use triple stages Peltier to cool low flux cameras ;)
(Delta T ~40°C below the ambient temp is usual for me)

But the stability is also important.
With the thermal bridge body/CMOS there's no way...

I don't think my 550D last too much, I can crack it open after warranty expires. then I'll try to hook up some copper inside.
in a complicated relationship with eos m.

SpcCb

Quote from: Doyle4 on September 11, 2013, 07:08:38 PM
This fps override is confusing me lol, i have learning difficulties so im sorry if i ask too many questions or repeat my self.

But could you explain to me what each mode does if possible? im mainly wanting to do day time ones, or do you think its best if i just use my shutter instead to keep cooling down etc?

Cheers
There's two main modes in FPSO (Frame Per Second Override):
A_. Low light
B_. Exact FPS
(other mode about Jello is another subject, to long to explain here shortly)

For A_. Low light mode:
Frames duration is long, computed from the CFPS value (Canon Frame Per Second).
Examples;
_. 5 FPS -> frames duration will be ~1/5s -> 0.2s
_. 0.5 FPS -> ~1/0.5 -> 2s. It's useful for night or low light conditions.

For B_. Exact FPS mode:
Frame duration can be short, computed from the CFPS and parameters. Parameters are in 'advanced...' in the menu.
Example; 5 FPS & FPS timer A=3420 -> frame duration could be from 0.2s (frame duration takes all the time between two frames, like in A mode) to 1/516s (frame duration takes only a fraction of the time between two frames). So you can take a short exposure (~1/500s) every 0.2s. It's useful for daylight low FPS.
By changing de FPS Timer A you can change the range of the frame duration.

I hope it could help..

And about temperature, more long is the frame duration, more the noise will have an high level.

Doyle4

Quote from: SpcCb on September 12, 2013, 12:25:28 AM
There's two main modes in FPSO (Frame Per Second Override):
A_. Low light
B_. Exact FPS
(other mode about Jello is another subject, to long to explain here shortly)

For A_. Low light mode:
Frames duration is long, computed from the CFPS value (Canon Frame Per Second).
Examples;
_. 5 FPS -> frames duration will be ~1/5s -> 0.2s
_. 0.5 FPS -> ~1/0.5 -> 2s. It's useful for night or low light conditions.

For B_. Exact FPS mode:
Frame duration can be short, computed from the CFPS and parameters. Parameters are in 'advanced...' in the menu.
Example; 5 FPS & FPS timer A=3420 -> frame duration could be from 0.2s (frame duration takes all the time between two frames, like in A mode) to 1/516s (frame duration takes only a fraction of the time between two frames). So you can take a short exposure (~1/500s) every 0.2s. It's useful for daylight low FPS.
By changing de FPS Timer A you can change the range of the frame duration.

I hope it could help..

And about temperature, more long is the frame duration, more the noise will have an high level.

Thank you very much! ill have ago tomorrow day with this :)

Doyle4

Had a play and makes more sense now thanks :)