Compact Flash Write Speeds

<p>Hello, <br>

I am in the market for a compact flash card for my Nikon D300. I have a very specific requirement, especially when it comes to the write speeds from the camera buffer. <br>

I am going to shoot some long exposure shots of a rapidly evolving scene (northern lights) and I don't want the camera to get locked up between shots for too long.<br>

I see different cards with different speeds (133X, 200X, 400X etc. with write speeds ranging from 15 MB/s, 30 MB/s, all the way to 90 MB/s). <br>

I wonder which one would be sufficient for my purposes? I would obviously get the fastest card if I could afford it, but since I can't, the question. <br>

I don't really care how much time it takes to transfer the files to the computer. <br>

I would appreciate your input.<br>

Thanks.<br>

Avi</p>

<p>What is "too long"? Generally speaking, unless you are shooting rapid fire like for sports or news reporting, or for tracking birds or other moving targets, you are very unlikely to see any results from a faster card. This is especially true because the camera will use the long exposure time to finish writing out the last shot if it hasn't completed when you shoot again. With that camera, even if you hold the shutter button down in continuous mode, you will get over 15 RAW shots or 30 JPEG shots with pretty much any card.</p>

<blockquote>

<p><em>"I am going to shoot some <strong>long</strong> exposure shots..."</em></p>

</blockquote>

<p>I would think that even the slowest card available would not be a problem with this scenario. As soon as the exposure is completed it's written to the camera buffer and you can immediately proceed to the next shot. The camera can then write the file to the card from the buffer while the next exposure is under way.</p>

<p>Maybe I misunderstand, but I don't see how you can ever fill the camera buffer in these circumstances. As long as the buffer is available, card speed shouldn't really matter.</p>

<p>I see.....I assumed that if the data transfer from the buffer to the card is faster then the camera becomes ready to shoot quicker. <br>

Coming to think of it, I think for long exposures (30 secs to 1 min), I am more limited by the noise reduction the camera performs than anything else. I can confirm that with NR on, the camera is unavailable for ~30secs between shots. <br>

I am not too worried about rapid fire scenarios and I am satisfied with the burst performance of my card. <br>

Thanks a lot for your help! <br>

Avi</p>

<p> </p>

<p>Thanks a lot folks! I just verified and you are right......as long as I don't use NR, it makes no difference to the shooting. <br>

But using NR makes a big difference and that is what is affecting the availability of the camera after a shot.<br>

Avi</p>

<blockquote>

<p><em>"I assumed that if the data transfer from the buffer to the card is faster then <strong>the camera becomes ready to shoot quicker</strong>."</em></p>

</blockquote>

<p>It does ... when the buffer is FULL. :-)</p>

<p>However, you are never going to fill the buffer with a single exposure every 30 seconds, as at even the slowest write speed the single file in the buffer will have been written to the card and cleared long before you finish the next exposure.</p>

<p>NR will be your limitation, as a second "dark exposure" equal in duration to your first exposure will taken, and card speed has no impact whatsoever on that function.</p>

<p>Hi Michael, <br>

Yes...my tests are in complete agreement with your statements. <br>

Thanks! Saves me a few bucks.<br>

Avi</p>