Interval Shooting - Randomly Stops

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bspeicephoto

New member
Hey everybody! So as we speak I'm doing a timelapse of stars to put together for star trails, but everytime I do the interval shooting (Settings: Manual Mode, 20sec, f/3.5, ISO 500; 1 second interval, 999 shots, start now) it stops after a little bit (definitely not 999 shots.). It's probably about 40 minutes to an hour that it just randomly stops shooting, and I'm not sure how to fix it. I've had this problem numerous times before, so I know it's not just a one time thing.

I know it's possible to use a program on a laptop or such, however I would rather stick to the free version while I can.

Specs:
Nikon D5100
18-55mm f/3.5-5.6
64gb SD extreme card
 
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bspeicephoto

New member
Well thing the being - if I use a program (Nikon Capture I think was something I used like a week ago for something else) I don't run into the issue whatsoever. It just shoots until the battery dies (or the power goes out and the external harddrive I was offloading pictures on) stops working. So it doesn't really make sense for that, although I could see that being a problem.
 
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Fork

Senior Member
I think the buffer is filling up. A 20 sec exposure will normally take 20 seconds to write to the memory card. On long exposures the camera's software will effectively take two "exposures" and combined them to cancel out noise. I think after a while the images will back up and the buffer will be full, therefore stopping the camera taking any more images. In your case the buffer is filling up before all your images have been shot.
 
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bspeicephoto

New member
Fork said:
I think the buffer is filling up. A 20 sec exposure will normally take 20 seconds to write to the memory card. On long exposures the camera's software will effectively take two "exposures" and combined them to cancel out noise. I think after a while the images will back up and the buffer will be full, therefore stopping the camera taking any more images. In your case the buffer is filling up before all your images have been shot.
Click to expand...

I could definitely see how that would be possible. Also, I'm using a 64gb SDXC card so I ultimately don't think it takes 20 seconds to write to the card. But do you think my problem would be fixed if I use a computer to offload pictures?
Still working on a free solution that works well.
 
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Fork

Senior Member
bspeicephoto said:
I could definitely see how that would be possible. Also, I'm using a 64gb SDXC card so I ultimately don't think it takes 20 seconds to write to the card. But do you think my problem would be fixed if I use a computer to offload pictures?
Still working on a free solution that works well.
Click to expand...

Unfortunately it's not the card that controls the writing speed. The speed of a memory card only governs how fast it can transfer images from the card to a computer. The software in your camera is unaffected.

The "buffer" I'm talking about is kind of like the camera's RAM, it gets full if it has too many shots to process (like a PC trying to run too many programs at once) and it freezes the camera until all the photos in the buffer have been processed.

To demonstrate, set your camera to burst mode (or continuous shooting mode) and hold the shutter button down. See how many shots it takes before it starts to struggle to keep the speed up. Eventually it will stop and you won't be able to do anything until it has processed all those images. That's because the camera's RAM can only do so much at one time and the shots waiting to be processed get backed up.

The best way to speed up the buffer is to lower the quality setting in-camera. If you can bare to set it to the next quality level down from whatever you're using, I think you'll find you'll get a few more shots out of it before it grinds to a halt. :)

As a side note: If you look into your viewfinder, down in the bottom right hand corner you will see a little box with the letter 'R' and a number a bit like this [R07]. That indicates how many shots the buffer can contain before it has to stop.

Do the holding shutter button down experiment again whilst looking through the viewfinder and watch that number. You'll see it go down the longer you hold the shutter. Eventually it will get to zero and the camera will stop shooting. You will then get a blank screen and the green 'saving' light on the back next to the screen will stay on until all shots have been processed. Once all those shots have been processed it will reset to its original number and you can hold the shutter down again.

Basically, because a 20 second shot takes so long to process, the camera hasn't finished processing by the time the next shot is being taken so it's processing and shooting at the same time - it will eventually get to the point where there are too many photos for it to process so it has no more RAM to use for the next shot.
 
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§am

Senior Member
Fork said:
Unfortunately it's not the card that controls the writing speed. The speed of a memory card only governs how fast it can transfer images from the card to a computer.
Click to expand...

Not entirely true I'm afraid.
The card doesn't necessarily control how fast it is written to, but it certainly does have a huge say in the matter.
Higher class SD cards will tend to write faster then lower class cards. How much difference in the writing speed will depends from manufacturer to manufactuer and also the model of the card.

As a guide, higher class cards (eg. Class 10) will be written to faster then say a Class 6 card.
One thing to note is, that read speed is nearly always much faster then write speed, and it's usually read speed that most manufacturers quote on their marketing blurb (unless they specifically mention the write speed of course).

I'm guessing your 64GB SDXC is at least a class 10 card, but if it's also a UHS-1 compatiable card, then you can be assured their will be a minimum write speed for that.
What card have you got out of interest?


Back to your problem in hand - I agree, the long exposure is probably filling up your buffer and it's taking more then a second at a time to write that to the card, however, I would imagine that the camera would be writing to the card as it 'takes the shot', so in theory it should not have that much data to write to the card backing up all the time to the point where it has no internal buffer space.
Play around with times between exposures see if that helps.
 
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Fork

Senior Member
SS381 said:
Not entirely true I'm afraid.
The card doesn't necessarily control how fast it is written to, but it certainly does have a huge say in the matter.
Higher class SD cards will tend to write faster then lower class cards. How much difference in the writing speed will depends from manufacturer to manufactuer and also the model of the card.

As a guide, higher class cards (eg. Class 10) will be written to faster then say a Class 6 card.
One thing to note is, that read speed is nearly always much faster then write speed, and it's usually read speed that most manufacturers quote on their marketing blurb (unless they specifically mention the write speed of course).

I'm guessing your 64GB SDXC is at least a class 10 card, but if it's also a UHS-1 compatiable card, then you can be assured their will be a minimum write speed for that.
What card have you got out of interest?


Back to your problem in hand - I agree, the long exposure is probably filling up your buffer and it's taking more then a second at a time to write that to the card, however, I would imagine that the camera would be writing to the card as it 'takes the shot', so in theory it should not have that much data to write to the card backing up all the time to the point where it has no internal buffer space.
Play around with times between exposures see if that helps.
Click to expand...


Ok, you may be right. But it still won't help the camera's software process the images any quicker, so my diagnosis still stands :)
 
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§am

Senior Member
Have a look at the section on this page headed "Memory Card Capacity" Nikon | Imaging Products | Specifications - Nikon D5100
and also at the "Continuous shooting and buffering" section here Nikon D5100 In-depth Review: Digital Photography Review

A quick search on the net will also provide a wealth of info on the matter, but a faster card does generally help the matter in hand (though there will be a point where the write speed does not matter as the camera can't keep up with writing the data).
 
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