Uncompressed vs. lossless NEF files

[Randy Stout]

Good day all:

I am shooting with a D300, and have the option of uncompressed NEF vs. lossless compressed NEF. The latter sounds appealing for smaller file sizes, but I always worry about any degradation in my images. I would appreciate folks opinions and practices in relation to this issue.

Good pictures to you all.

Randy

[Alfred Forns]

No degradation The capture time will be longer Would recommend not using it !!!

[Robert O'Toole]

Each report I have read usually has the same conclusion that there isnt any visible degradation but I have never tried on my own. My D300 is on Uncomp NEF. Will be interesting to hear from others on BPN.

Robert

[Randy Stout]

Thanks Alfred:

I would have assumed shorter capture times because of the smaller file size, but didn't take into account the processing required to generate the smaller file. In that case, its a no brainer for me. Cards are cheap, storage is cheap, missing that critical shot is a bummer!

Thanks

Randy

[George DeCamp]

I've never noticed a difference on the D3 or D2x. I would assume the same holds true for the D300. That said when I am home and have plenty of HD space, I use uncompressed. Sometimes on the road I switch to lossless compressed and still have yet to figure out which is which.

[john crookes]

on the Nikon site and the nikonians web site people have found that it is actually faster to photograph in the lossless mode over uncompressed in the d3 and the d300 in 14bit mode.

also on a 4gb card thats about 85 more photos before changing cards

I photograph with 16 gig card and that means having almost an extra 4 gig card capacity when i photograph in lossless

[Randy Stout]

John:

Can you tell any quality difference at all, even in 14 bit, uncompressed vs. lossless compressed?

Randy

[john crookes]

Not in any of the files that I have tried it with

[E.J. Peiker]

The very definition of lossless compression means that there will be absolutely no difference. Basically a lossless compression algorithm oversimplified works like this. Lets say there are 100 pixels in a row with the same color value (common in skies) so rather than storing the same color values 100 times it simply says, the next 100 pixels have this color value. When you convert this file, the original pixel values are restored from that information. So a photo that has large expanses of the same tonal values will be much more compressible than one that doesn't. So there is no downside from an image quality standpoint to shoot lossless compression NEF.

A lossy compression algorithm on the other hand will compress similar values that aren't the same into a single value - that can show some degradation depending on how aggressive the compression setting is - JPEG does this.

Canon RAW files have always been compressed RAW which is why file sizes for the same megapixels as Nikon were always a lot smaller (for example a 16.7MP EOS 1Ds2 file is smaller than a 12MP D2x file). In the latest round of cameras Nikon added lossless compression as an option to their NEF files.

Finally, whether or not shooting compressed or uncompressed is faster is dependent on a number of things including the speed of the compression algorithm and the processor it runs on and the speed of the flash card and the pipeline feeding the flash card. With a very slow card where it is the limiter, compressed will be faster. With a very fast card where it isn't the limiter then uncompressed may be faster. I don't know enough about the Nikon pipeline (yet) to assess whether a card will ever be the limiter or if the processor or data pipeline is ever the limiter.

[Randy Stout]

EJ:

Thanks for the input. I will give it a try while in Florida, where my cards will be filled to the brim (I hope!)