Camera stopped working.

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paul04

Senior Member
I was outside last night, set the camera up to take pictures of fireworks, 1st couple of pictures were fine, then the camera just froze on me, would not do anything,

Just had the little green light on the back of the camera.

It would not turn on or off, in the end I took the battery out, memory card out, and removed the lens, left it for about 10 minutes, put lens back on,battery and memory card back in, turned the camera back on, and it worked, It had a message on the screen saying " press shutter to reset"

I can only think it got a bit cold from being outside. took some pictures this morning,and its working fine.

Any one else had the same problem?
 
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SteveH

Senior Member
Was the previous shot to it freezing a long exposure? If so, there may not be a problem.... Check the settings for "Long exposure noise reduction".

If you take a 30 second shot for example, the camera will record a LOT of info in that 30 seconds... It will then spend another 30 seconds after the shutter closes doing noise reduction.... All of this then needs to be written to the memory card. During this time, the green light will be on and the camera won't be able to take another shot.

How is the camera now? Check the settings and try again with a long exposure tonight, but bear in mind that a 30 second exposure could take 1:10 - 1:30 mins to complete from shutter opening to the camera being ready to take another shot. You speed this process up by disabling long exposure noise reduction, but you will have noisier shots.


ETA - The camera will not power off until the buffer is written to the memory card, which is why when you powered it off, it stayed on until you removed the battery.
 
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J-see

Senior Member
Does it say "Job nr" when you look through the viewfinder? If, it's the noise filter at work. The cam won't respond to anything during and it can take ages.
 
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Felisek

Senior Member
SteveH said:
If you take a 30 second shot for example, the camera will record a LOT of info in that 30 seconds... It will then spend another 30 seconds after the shutter closes doing noise reduction.... All of this then needs to be written to the memory card. During this time, the green light will be on and the camera won't be able to take another shot.
Click to expand...

To be more precise, the amount of information recored in a long exposure is similar to that from a short exposure. During an exposure pixels convert arriving photons into charge, which is accumulated in a special element. When the shutter is closed these charges are read by camera's electronics. I might be wrong, but I don't thing camera is recording or processing any information when the shutter is open.

After a long exposure the camera takes a blank picture (with the shutter closed) of the same exposure time as the main picture. This takes time: as you said, if you take a 30-s exposure, the camera will take another 30-s blank exposure afterwards. This blank frame is used to measure noise caused by the heat in the sensor. It is a different type of noise than the high-ISO noise, it makes parts of the frame brighter. Then, the blank frame is subtracted from the image, I don't suppose this process is going to take much time in a modern camera.

But you are right, the camera is busy for a while after taking a long exposure and will not take another shot.
 
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J-see

Senior Member
Felisek said:
After a long exposure the camera takes a blank picture (with the shutter closed) of the same exposure time as the main picture. This takes time: as you said, if you take a 30-s exposure, the camera will take another 30-s blank exposure afterwards. This blank frame is used to measure noise caused by the heat in the sensor. It is a different type of noise than the high-ISO noise, it makes parts of the frame brighter. Then, the blank frame is subtracted from the image, I don't suppose this process is going to take much time in a modern camera.
Click to expand...

That solves the riddle why it took so long even at 100 ISO. I read somewhere it could double the write time at higher ISO but my experience was that even at low ISO, long exposure shots took ages to process. This explains exactly why it takes that long even at lowest ISO. Thanks.
 
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paul04

Senior Member
Thanks for your replies,

it was about 5 minutes after the last shot when it froze, I went to take the next picture, and normally you here the shutter move as you take the picture,, but nothing.

I think I have worked out what it is., the SD card
Taking some pictures this morning and everything was fine, I put the sd card in the computer to look at the pictures, there was 2 folders on the card, one with this pictures on the card before it froze, then another folder with pictures after it froze.

I tried to delete some pictures off the card, but it would not let me, just said the card is write protected.(but it was not)
So I saved the pictures, put the card back in the camera, which let me delete the pictures

I have formatted the card now, hopefully that should fix it, its a sandisk ultra 16GB so a good card.
 
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