no change in capacity between uncompressed RAW and lossless compressd RAW

[jeelan]

hi guys

i've got a D300 and i've recently started shooting in RAW. On the D300,i hv the option of shooting in RAW Uncompressed, Lossy compressed or lossless compressed and also in 12bit or 14bit.

I'm using a Sandisk Extreme III 8GB card.

i've set the camera to shoot in 12bit, however when selecting either lossless compressed, OR uncompressed, there is no change in the capacity of the card (on a freshly formated card, it reads 394 on the LCD). This figure doesnt change irrespective of whether Lossless compressed, or uncompressd RAW is selected.

IF i select lossy compressed, this figure changes to 541 (still 12 bit) and with 14bit selected, the 394 drops to 303 (for lossless compressed, AND uncompressed) or 448 for lossy compressed...

i'm surprised with this because Nikon's manual states that there is around 30% file reduction for uncompressed to lossless compressed and this is not showing on the capacity calculator on the camera.

for travelling on extended trips ie 4-5 weeks, i've got 3 of these CF cards (Extreme 3m 8gb) but i'm wondering if that's going to be enough.

can anyone give any feedback on this or share what their respective card capacities are?

I noticed that if i plug in the D300 to my MAC and read the CF card from the computer, thte 8GB card (after in camera formatting) only shows a capacity of 7.2GB....

these results are reflected on all 3 CF cards that i've got so i can safely rule out faulty card...

and feedback would be appreciated

cheers
Jeelan

[farmer_rob]

I believe it is hard to predict accurate compression ratios for lossless compression of images. I assume you are starting with a blank card and looking at the total available. Nikon probably take the uncompressed size and predict the number of images, using that for both compressed and uncompressed. If you take a few shots with lossless compression, you may find the capacity will not be reduced by as many shots as you have taken.

(BTW, if you are shooting RAW, I just don't think you'll have anywhere near enough capacity. I took over 1000 shots on a 14 day holiday to India. You might need to look at some form of portable hard disk storage.)

[I @ M]

jeelan, the choices of formats for the D300 are different to the D200 but what I do know is that if I select to shoot in uncompressed NEF then the counter says 120 pictures is the max I will fit on a 2gb card and it is pretty spot on.

If I set the camera to shoot compressed NEF, the counter still says 120 images --- but ---- it will actually hold between 180 and 215.

[jeelan]

thanks for the feedback guys..





(BTW, if you are shooting RAW, I just don't think you'll have anywhere near enough capacity. I took over 1000 shots on a 14 day holiday to India. You might need to look at some form of portable hard disk storage.)

hmm.. i'm not a big fan of travelling with too many gadgets and gizmos. Until this year (which is when i got my first DSLR) i've been more into camcorders as a means of recording my travels, so for the last 5-6 yrs i've been travelling with a single camcorder that can also take still shots...

now i've got Sony camcorder which takes 10MP stills so i'm sort of torn between taking "everything" or sticking to camcorder and perhaps a compact still....

hmmm...if only i could shoot RAW with my camcorder :D :D

cheers
jeelan

[arthurking83]

The number of shots(remaining) on the LCD display is only a 'guide' as to how much space may be available. It;s not absolute and will depend greatly on many variables with each shot. ie. how many colours if it;s looking more monotone.. etc plus the compression/quality factor.

BUT if you set the quality to 14 bit, as opposed to 12 bit you do lose a lot of space on a 8gig card.

The actual number of proper binary bytes on the card is correctly registered as 7 point something, and not 8, as 8 is the number of bytes on the card measured as 1000 bytes.. and not 1024. It's the same deal with all drives of any kind, where your 320Gig Hdd is actually more like 296 or so!

My 8Gig no name card only shows 7.55Gigs via the PC's properties context menu also.

Some cards do have an ability to hold a few more images than others(for the same nominal capacity), I have two 4 gig cards of different brands and the Sandisk version is slightly smaller, maybe by 20-50meg or so, because it reads at least 2 shots less than the Apacer Card I have of the same 4gig capacity.

My D300 using that same no name 8G card indicates 390 images as a standard procedure from the word go! But I have had over 400 shots on that card once the camera starts to get a better idea of how many megs each file actually contains. It's then averaged out and recalculated as the number of files on the card increases, so you will almost invariably get more shots on a card than the display originally indicates. You may actually get less(I never have) if you find yourself taking lots of images with lots of different colours in the scene and with various Picture Control settings(I think Vivid with Saturation and Contrast enhancements) enabled too... I think!
But some files can be as big as 25 or more Megs, others may only be a light weight as 18Megs(12 bit RAW), whereas 14 bit NEF's can be as large as 32Megs(so far that I've seen).

The level of compression is also an estimate too. Lossless compressed may yield you a few more shots again.. could be 50 more, by the time you have half filled the card.

3x 8gig cards may be fine, and what I'd do is review them after every night and definitely delete any non keepers. You could also purchase a few cheapo CF cards along on your travels or try to get your full cards backed up to DVD disks somewhere??
Of course that assumes you are travelling to 'civilised' places, and not totally remote places where these services aren't available to you.