Why are my D3 NEF files SMALLER than my D2X?

I just shot some test images today with my new Nikon D3.

I noticed that a number of .NEF images today (FX format, ISO 200, 14 bit
RAW) are 15-16mb each in size.

Two years ago I shot a number of .NEF images with my D2X that are 19-20mb
each.

Can anyone help explain why they would be SMALLER in a D3?

I want to make sure I'm getting maximum quality out of my D3.

BTW, I am simply thrilled and stunned with this D3's features, performance
and everything else about it!

TIA---

John

"John Smith" <JohnSmith.RemoveThis@aol.com> wrote:
>I just shot some test images today with my new Nikon D3.
>
>I noticed that a number of .NEF images today (FX format, ISO 200, 14 bit
>RAW) are 15-16mb each in size.
>
>Two years ago I shot a number of .NEF images with my D2X that are 19-20mb
>each.

The D2x has two modes for saving raw data with NEF
files. Both are 12 bit files, but one uses a look up
table to compress the data by reducing the total number
of values from 4096 down to less than 700. Using the
compressed format results in 9-14Mb files rather than
the 19-21Mb files of the uncompressed mode.

Unfortunately the compression is lossy, though only
slightly so and only in the highlights (where it usually
is not important).

>Can anyone help explain why they would be SMALLER in a D3?

I haven't seen anything yet that gives the exact details
on what the D3 and D300 NEF files use, though it very
clearly is available (granted, I haven't even tried to
find out what it is).

As you will note on Page 68 of the D3 manual, in
addition to switching between 12 bit or 14 bit data, the
D3 has two compression formats, as well as the
uncompressed format.

Here is a chart showing file sizes that I got for the
different format with one particular image:

12 bit 14 bit

Compression 12.0 Mb 15.1 Mb
Lossless Compression 12.8 Mb 15.9 Mb
Uncompressed 19.6 Mb 25.0 Mb

First, you'll notice that 12 bit uncompressed NEF is
just about the same as with the D2x uncompressed NEF.

Next you'll note that 14 bit files are indeed
significantly larger. And it appears that, at least for
this particular image, the lossless compression is
almost as good as the lossy compression.

I didn't take a similar image with the D2x, so I can't
compare the compression between that and the D3. I've
seen the D2x (lossy) compression generate files from 8Mb
to 13 Mb, so the above is within that same range.

>I want to make sure I'm getting maximum quality out of my D3.

Go to the "Shooting Menu", the scroll it down almost
half way, to the "NEF (RAW) recording" item. That gives
you two selections.

The top selection is "Type", go there and select
"Uncompressed" or "Lossless compressed". Probably
"Uncompressed" is the best choice, given that we aren't
really sure what "Lossless compressed" actually is. I
would _not_ advise selecting "Compressed" until you are
aware of exactly what it does.

The bottom selection is "NEF (RAW) bit depth", and there
you can pick 12 or 14 bits. I'd recommend 14 for
absolute best performance.

Just be advised that you'll need a *lot* of disk space!

You can use only half the disk space by using 12 bit and
the lossless compression, but you'll also have less
performance. I'm not sure what "Lossless compression"
does, but the regular compressed format will lose fine
detail in the upper two zones. That would be important
for white wedding dresses, bright flowers, and that sort
of object. The difference between 12 bit and 14 bit
files is probably about 1 zone worth of dynamic range
added to the the low end, though in theory it would be 2
fstops, and in fact at higher ISO settings it probably
is less than 1 fstop (due to noise).

>BTW, I am simply thrilled and stunned with this D3's features, performance
>and everything else about it!

In the last three weeks I've shot only a few images that
a D2x is able to get (tonight I got some fireworks, and
that probably would not have been much different, for
example). But this week I've been shooting local
"Arctic Games", which are traditional Eskimo indoor
sporting events, at a location with poor lighting where
I've just never been able to get good available light
images before. I'm shooting at ISO 3200 and 6400, which
provides the ability to adjust shutter speeds up or down
depending on how much motion blur is desired.

It's astounding...

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd.RemoveThis@apaflo.com