Since I'm chewing up memory cards twice as fast as my D70s, I figured I'd check out the rebates and get some more CF cards for some upcoming trips.

I noticed that my D300 tells me on a newly formatted 8 GB card, that I get 394 pictures. Now, its a 12 MP camera, on raw only, so roughly 12 MB / pic, or what I thought should be about 680 pics for that card.

So I started shooting, and rattled off pics until the sensor told me I had 200 pics left. Guess what - I had shot 374 pics, or what would have been about 750 pics. I realize there is some fluctuation pic to pic, so the 680 to 750 doesn't concern me.

What bugs me is the way it calculates the number and then recalculates continually. Why can't it just be even close - the number almost means nothing to me now, particularly if I'm shooting a combination of RAW, Raw + JPG or JPG only on the same card.

To the other D300 owners, are you seeing the same thing, or do I potentially have a problem?

 

hmmm - I found something. Apparently I have a setting for 3 types of RAW/NEF files, and two bit depth settings..

Lossless compressed 12 bit: 10.5 MB, 14 bit 13.9MB
NEF Compressed 12 bit: 9.5 MB, 14 bit 11.9 MB
NEF Uncompressed 12 bit: 19 MB, 14 bit 25 MB

From some forums on Nikonians, it appears that the algorithm is based on the uncompressed format, and adjusts as you shoot. So now that I know that, I'll ask two different questions:

If a raw file is really what the sensor sees, should a file be ~12 MB for a 12 MP camera?, and
Is there value in changing the settings from lossless 12 bit to anything else for my normal, daily, hobbyist shooting?

 

1 pixel is not equal to 1 byte.
1 byte = 8 bits.
1 pixel = 12 bits or 14 bits.
so
1 pixel = 1.5 or 1.75 byte.
12 mega pixel in D300 is about 18 or 21 mb. to make the calculation more complex, 1Kb is not 1,000 bytes. it's 1024 bytes. that means, 1Mb is in fact, 1,048,576 bytes. to make the matters worse, there are header, footer, and exif information is also embeded.

i do not know how many photos it should hold on a 8Gb CF, however, all my 2Gb's can hold about 86 photos as camera says when it's empty. however, since i'm using 12 bit lossless compression, i get about 140 photos per 2 gb. unless you are printing larger than 20x24, you won't see much difference.

 

Thanks for the math lesson Paul. The 1M bytes vs. 1.024 MB isn't much of a difference for me to worry about, it was the other stuff. Also, the header/exif and metadata aren't that much in relation to a 10+ MB file., so I didn't bother to consider those. The byte conversion vs pixels and depth is the difference.

As for printing, I've got a 16x20 from a 6MP JPEG image from my D70 that is on my wall. Printing really large stuff isn't a big worry of mine.

THANKS!

 

higher ISO files require more space too, keep that in mind.