Compressed RAW Images?

R8JimBob88

R8JimBob88

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James Stockton
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Sorry for asking this as this time on a Saturday morning....

Just that my new D200 gives me the option to shoot RAW and also Compressed RAW? Obviously the compressed raw images are much smaller in size and I will fit more to a CF card but are there any downsides to this? Kind of defeats the object to shooting regular RAW doesnt it?

Please enlighten me :)
 
speaking with 100% lack of knowledge
I would imagine there is a processing overhead
so picture save time would be slower
 
So if it is lossless, is there any reason not to use it apart from it takes longer to write to CF?
 
compressed_menu.jpg


I like the way the manual describes it "with little drop of quality" :)

To my mind that says it's not entirely loss-less or they are protecting themselves. Further in the manual it states even the compressed RAW files are 12 bit.
 
I always use compressed RAWs. Not really noted any problems with speed. You get around twice as many pics on a card, but be aware that the 'pictures remaining' does not take this into account. So if you would normally get 200 pics on a card, switch to compressed raw, it will still say 200 remaining, but you will actually get more like 400.

HTH
 
I have been shooting compressed. Uncompressed the file sizes are 15-20mb's and the compressed ones are approx 6-8mb's. Visually I cant tell any difference!

Thats what I found Joe, I have a small 1 gig card in, shooting compressed raw and small fine jpegs and it said I had 52 images to a full card. 69 shots later it said I still had 19 left :D
 
The reason for the disparity between the display and what you can 'fit on' has been there since D100 (maybe with D1 as well). It's way of making sure that, if do decide to switch to uncompressed, you will still have the displayed capacity of the card.

Not only that, the compression algorithm hardly ever produces the same file size - it depends on how the data can be 'lost' so to speak. Therefore the display shows the minimum that could be stored.
 
chuckles said:
I like the way the manual describes it "with little drop of quality" :)

To my mind that says it's not entirely loss-less or they are protecting themselves. Further in the manual it states even the compressed RAW files are 12 bit.
Click to expand...

I see, so they are most likely removing some information from the shots when compressing them. If they're 12-bit and without any in-camera post processing, they still beat jpegs IMO.
 
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