timelaps vs display off, temperature etc (was Re: fixedint.lua...)

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Generally speaking, you are probably better off stacking instead of using such long exposures anyway.

Yes of course…
I just wanted to make a measurement to see how high the senor temperature of my M3 is in long time exposure.
It looks like that just Live View heats up the sensor significantly more than long time exposure.

Interesting in the long time exposure was that the optics temperature was higher than that of the sensor. I've never seen that before. Presumably, in this state, the surrounding electronics heats up more than the sensor.
« Last Edit: 14 / December / 2017, 13:44:58 by reyalp »

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Offline reyalp

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On some cameras at least, the "sensor" temperature actually comes from a separate component on the PCB that holds the sensor, rather than being built into the sensor chip itself. I'm not sure where the "optical" temperature is measured... come to think of it, I haven't thought about what optical temperature means on an ILC. Have you checked the value with the lens removed?
Don't forget what the H stands for.

Have you checked the value with the lens removed?
Yes, I still got valid temperature values without lenses and with adapted manual lenses.
It looks like that the sensor temperature on the M3 goes faster higher as on G1x.
What happens in the waiting time, if I have TV = 5s and interval = 30s and display mode is off?
Does the camera still have activities like on Live View (getting data from the senor)?

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Offline Ant

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Does the camera still have activities like on Live View (getting data from the senor)?

AFAIK you have exnernal power supply.
Why do not you measure current consumption?


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Offline reyalp

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Does the camera still have activities like on Live View (getting data from the senor)?
Reading out CMOS (and CCD) is destructive, so live view definitely isn't being updated during exposure. The display hardware (GPU, LCD driver etc) may still be running, but it should be doing relatively little.
Don't forget what the H stands for.

AFAIK you have exnernal power supply.

Not yet for the M3. I still not have decided if I buy the cheap one and have to confirm all the time.
If have on for G1x, SX50, IXUS160 and S110.

Why do not you measure current consumption?
When I have one, I could measure with display on and off. I did this in the past with S110 and this was a big difference. But can I be sure; the reading off senor data is disabled?
On G1x I could switch display off on Canon menu and compare this with CHDK display off….

Reading out CMOS (and CCD) is destructive, so live view definitely isn't being updated during exposure.
Yes of course, but what happens in the time between the next shoot?

Would the following measurement make sense?
Fixedint, shots=20, interval=60s, tv=30s, Display=Off (or Blt?)
One run with Canon Dark Frame and one run without Canon Dark Frame and comparing of sensor temperature…

There is one older rawopint run with M3. This shows how the senor temperature goes down on longer exposer times..

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Offline reyalp

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Yes of course, but what happens in the time between the next shoot?
Generally, CHDK set_lcd_display does not turn of the sensor, and of course set_backlight just changes the backlight. Canon firmware options that turn off the display generally do turn off, for example if set "display off after N seconds" in the canon menu, or if your camera has a key that directly turns the display off. This has a big effect on temperature and power usage.

You can use the chdkptp live view to see if the sensor was turned off, it will show the last frame
Don't forget what the H stands for.

Generally, CHDK set_lcd_display does not turn of the sensor, and of course set_backlight just changes the backlight.
Yes, of course…
You can use the chdkptp live view to see if the sensor was turned off, it will show the last frame
In chdkptp Live I select the ‘Viewfinder’.
Then I sent command:
=set_lcd_display(0) or =set_backlight(0)
The Display goes off on the Cam but I still have live view on chdkptp. That means the sensor is still active and got heated. (M3 and G1x)

or if your camera has a key that directly turns the display off
If I do this on G1x, then live view stops on chdkptp.
But that's what should be done in the waiting time for time-lapse or?

May be you should move this discussion to a separate thread…


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Offline reyalp

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If I do this on G1x, then live view stops on chdkptp.
But that's what should be done in the waiting time for time-lapse or?
If the interval is slow enough that there is a significant time between shots, this will keep temperature down and save battery. If the interval is mostly taken up by shooting, I wouldn't expect it to make much difference.

I don't know what the effect is for scripts like fixedint and rawop that hold down half press ("quick" mode) or full press ("cont") all the time. The "turn display off after ..." setting won't work in this case, but it's possible the camera keeps the sensor on when half press is held on cameras with a display off key too. In cont mode, I would expect the sensor is kept on all the time, but again that's just a guess.

There's so much variation in the canon options it's hard to make a portable script that uses them, although I believe waterwingz "ultimate" covers most https://chdk.setepontos.com/index.php?topic=9969.0
Don't forget what the H stands for.

If the interval is slow enough that there is a significant time between shots, this will keep temperature down and save battery.
On my typical daytime time-lapse the ratio is:
 exposure time < 1s  and interval > 5s 
it's worth for me to think about it….

I made just some measurements on my G1x
Replay mode = 0,12A
Record Mode = 0,40A
Record Mode Display off = 0,34A
Record Mode Backlight off =  0,37A
Record Mode Both off = 0,34A
Record Mode Display off on Canon Menu = 0,15A
So, on G1x it’s a huge difference of current if I use Display off on Canon Menu. It looks like that I can do time-lapse when I switch display off before I start the script

I don't know what the effect is for scripts like fixedint and rawop that hold down half press ("quick" mode) or full press ("cont") all the time. The "turn display off after ..." setting won't work in this case, but it's possible the camera keeps the sensor on when half press is held on cameras with a display off key too. In cont mode, I would expect the sensor is kept on all the time, but again that's just a guess.
This is the next measurement which I try to do… also with Display off on Canon Menu

There's so much variation in the canon options it's hard to make a portable script that uses them, although I believe waterwingz "ultimate" covers most https://chdk.setepontos.com/index.php?topic=9969.0
I have already looked at it and did not understand everything. it is time to read it again ...

 

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