Slow Write Speeds with Long Exposures

I have two 16GB Lexar Pro's, one 400x and the other 600x. When I shoot long exposures (30 sec - 1 minute) my 7D says BUSY when it's writing. Today I was using the 600x and it was taking up to almost a minute to write, in the mean time losing shots at sunrise. Is this normal for the speed of this card? Should I consider a 1000x card? Will it make much difference? And is there really a difference between the 1000x and the 1066x cards?

Thanks

I only use the Sandisk Extremes. They never take that long to write to the card a 30s shot will take moments, a 10 minute shot will not take a minute to write... Not sure if that is a lexar issue, or whether you are storing RAW + Jpeg (that would double your write time)?

Ots not the card, its the processing by the camera if you have long exposure noise reduction turned on it uses a dark frame to rduce noise. I dont want to attempt to describe the process but the processing rakes approximately the same rjme as your exposure.

gonzogolf wrote in post #17314284
Ots not the card, its the processing by the camera if you have long exposure noise reduction turned on it uses a dark frame to rduce noise. I dont want to attempt to describe the process but the processing rakes approximately the same rjme as your exposure.

I was thinking that as well, but he did say "sunrise", so i thought it probably wasn't that..

Thanks, that was it.

Just checked my settings:

"Long Exp. noise reduction
2: On

Since I haven't tested, would it be just as effective to turn NR off and apply it later in PP? Other suggestions?

You likely dont need it for longish exposures with lots of color snd detsil. It helps a lot on astro-Photography and shots where a good part of the scene is black. Try a shot both ways to see if it matters.

Ynot wrote in post #17314456
Thanks, that was it.

Just checked my settings:

"Long Exp. noise reduction
2: On

Since I haven't tested, would it be just as effective to turn NR off and apply it later in PP? Other suggestions?

It could help some - you can take a blank frame of the typical exposure length (or several of different lengths), invert them and merge them with the original photos. That's what LENR does, and why it takes so long (each exposure is followed by a phantom black exposure of the same duration and the two are sandwiched to cancel out any hot spots. But LENR isn't quite the same as regular post-processing NR, which tries to identify odd pixels based on what's around them.

Thanks all. I've turned it off for now. You've also reminded me how it was set in the first place. A couple months ago I took an astro photo workshop where we were told to turn LENR on. Guess I forgot that it was set.

How does LENR work on non-long exposure shots?

Ynot wrote in post #17314694
Thanks all. I've turned it off for now. You've also reminded me how it was set in the first place. A couple months ago I took an astro photo workshop where we were told to turn LENR on. Guess I forgot that it was set.

How does LENR work on non-long exposure shots?

It doesnt. It only activates on long exposures.

Great, thanks a bunch.

Thanks everyone!

You might regret turning that feature off. You can end up with hundreds of green, red, and yellow colored pixels in your final image that will take much longer to clean in post than the extra minute you have to wait after taking the picture. I keep mine set to "auto" and the camera is generally pretty good about deciding when it is needed.

Are you shooting RAW? Granted I don't have NR turned on in my 7D. But I do A LOT of long exposures and after a 30 second exposure it takes maybe 0.25 seconds to clear. I'm using Sandisk Extreme 60MB/s cards...nothing too fancy.

ptcanon3ti wrote in post #17316175
Are you shooting RAW? Granted I don't have NR turned on in my 7D. But I do A LOT of long exposures and after a 30 second exposure it takes maybe 0.25 seconds to clear. I'm using Sandisk Extreme 60MB/s cards...nothing too fancy.

If you are shooting RAW and have long exposure noise reduction turned ON, the noise reduction process should take exactly as long as the original exposure. If that is not happening, then your camera is not functioning properly. If you have long exposure noise reduction set to AUTO, then I find it only kicks in once you get to the 1 minute range.

Mark-B wrote in post #17325668
If you are shooting RAW and have long exposure noise reduction turned ON, the noise reduction process should take exactly as long as the original exposure. If that is not happening, then your camera is not functioning properly. If you have long exposure noise reduction set to AUTO, then I find it only kicks in once you get to the 1 minute range.

I have NR off. I can't wait 30 secs for a 30 sec. exposure. Especially when doing long exp. HDR.

Thanks Mark, I'll give the Auto setting a try.