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View Full Version : A75 + TimeLapse of Sun = Damage?


scorpius
3rd of January 2005 (Mon), 18:03
I'm thinking of buying the A75. Will I destroy the CCD if I take repeated pics of the setting sun?

I have a 10 year old apple quicktake digital camera and have made many hour-long time-lapses of the setting sun and there was no damage at all. See my example here:
http://www.redrival.com/scorpius/Nov17.m1v (http://www.redrival.com/scorpius/Nov17.m1v)

Anyway, I would keep the camera aimed at the horizon, so the sun wouldn't be very high in the sky (and, therefore, not as intense as it is at noon). I'd let the camera's auto setting choose the exposure.

So is the A75's CCD too sensitive to handle the sunset?

BruceC
3rd of January 2005 (Mon), 18:26
My A75 manual says not to point the camara directly into the sun which could damage your eyes. So I dont know if it says that for your safety of the A75s. How do you do that timelapses?

Bodryn
3rd of January 2005 (Mon), 18:41
I'm no expert but I think probably the spot of focus where the sun hit the CCD would probably damage it due to excess heat buildup, if the sun is higher in the sky. You might try an experiment where you hold a similar sized lens out to the sun and hold a piece of paper up at the sun's focus. Or even just hold your finger at the focus. If your finger gets too hot, consider what that might do to the CCD. Electronic devices as a rule do not handle excess heat very well. But at low sun altitudes you probably can get away with it.

Moppie
3rd of January 2005 (Mon), 18:49
What your doing is simply taking lots of shots of the setting sun, with out focusing directly on it.

I see no reason why it should harm the CCD, the setting sun is so low in intensity there won't be any problem.
I have nearly a hundred photos of sunsets, all taken with my A80, and none of them have done any noticable damage.

Shooting the sun repeatedly at midday however would lead to damage :)

scorpius
4th of January 2005 (Tue), 15:51
Bruce, to make the timelapse, I modified Apple's SDK to enable the cam to snap a picture once every 20 seconds and save it as a sequentially numbered tga file. I set it to go for 5 hours, then made the mpeg with the free tmpeg encoder. The camera has to be connected to the PC and a power adapter (the batteries only last for about ten pics).

The quality isn't that great, so I need to upgrade my camera. I want to buy an A75 because it can be on for 16 hours until the batteries die. All I have to do is modify the firmware to allow timelapse mode. But the A75 is out of stock in my area so I might have to go with another model, or wait.

Moppie, was the sun still yellow in your photos, or was it very dim and red?

Moppie
4th of January 2005 (Tue), 20:28
Moppie, was the sun still yellow in your photos, or was it very dim and red?

Most were dim and red, getting close to the Horizon.
I have a few wheres its still quite yellow.

If you point the camera at any strong light source for any length of time it will damage the CCD, I imagine your old Kodak suffered some damage taking the time exposures.
But its cumlative, doing it once might not leave any noticeable effects, doing it 5 times starting at 4pm in the middle of summer will damage it.
But it will damage any digital camera.

BruceC
4th of January 2005 (Tue), 20:57
Ah i see change the firmware. Could you direct me to a website where I might learn alittle about this stuff. Also you can get the A75 from amazon.com for $148 shipped new. Thats where I just bought mine.

scorpius
7th of January 2005 (Fri), 17:41
The canon cameras use good-old DOS as the operating system. So you have to know some assembly (or C) to make modifications. Are you interested in timelapse also? Let me know if you want to help me figure it out.

These two sites have loads of info about firmware:
http://groups.yahoo.com/group/PowerShot_programming_research
http://groups.yahoo.com/group/canondigicamhacking

This allows for longer movies:
http://nostromo.dynalias.org/canonhacking

BruceC
7th of January 2005 (Fri), 18:22
wow this is really cool. I used to love DOS! Still do. Thanks!

scorpius
7th of January 2005 (Fri), 22:50
Can anyone verify if the A75 works with the Remote Capture application? I want to use it for time lapses, and want to know how many frames at 640x480 I can capture per second. I have a USB 2.0 port and a 3.6GHz PC -- how fast does it tranfer from the CF card?