Still camera - pic storage requirements?

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Hi all,
how do you get from image mega pixels to number of pics stored on a card?

Say 1Gb card and 8Mp image with no compression, how many pics?

And with lossless compression, how many extra pics can be squeezed onto the card?

I am not interested in lossy compression.
 
Hi Andrew

Figure on 24 bits per pixel, so 3 bytes per pixel. 8MPx3 give you 24MB to store 1 pic without compression.

But, it that number certainly looks wrong. My RebelXT is an 8MP unit, shooting in raw gives about 6 to 8MB per pic. So I guess, RAW mode already contains some form of lossless compression.

Shooting JPEG 'fine' mode gives about 2.5 to 3MB per pic.


1GB = 1000MB. Figure from there..

Cheers!

Clem
 
Hi,
that 24Mb estimate matches up with Olympus TIFF storage of 23.3MB per pic.

But they also quote RAW @ 13.5MB/.

What is Jpeg? are these lossy compression or lossless?
Jpeg gives 1.9MB/, 4.3MB/ and 6.1MB/

So TIFF gets 42pics onto 1GB
and RAW gets 74pics onto 1GB without any loss. Is that right?
 
Hi,

I'd expect RAW to actually vary dependent on lighting etc, dependent on how redundant the data is.

JPEG is definitely lossy. It's the compression used on most of the images you see on the web, now that GIF has copyright etc.

Yep, 42 and about 74 or 75 pics for tiff and raw, in your case...

Cheers!
 
Personally i don't bother with raw nor tiff;
my 4 mpixel camera can take upto 3 shots per second using jpeg,
it takes 2-3 seconds for one shot when i use tiff.

When editing, i always save "inbetween edits"using a lossless format, bmp or tiff.
Every time you save, depending on the editing you did, there is a potential loss using jpeg.
This also depends on the jpeg-quality settings in your editing-software.
When i need the final result f.i. for web use, i convert to jpg.

Also i ALWAYS keep the original jpg.

Klaas
 
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