The camera does a 12-bit Analog to Digital Conversion (ADC) of the voltages accumulated by the CCD.
These 12-bit values are stored in the Nef file. This is the Raw data.
If it's a compressed Nef file, like the D70, some bits are lost to compression.
For more info on that see Nikon D70 compressed NEF files are lossy

Yes, the Nef file contains the Raw data, and more; as explained in the original post.

Bitmap is an oxymoron that goes back to monochrome images.
Nowadays bitmap has come to mean a format with values for individual pixels as opposed to a vector or other format.
So yes, I consider a Raw file to be a bitmap; it's just that each pixel is only red, green, or blue.

FWIW, the Nef file also has a small TIFF bitmap and two Jpegs embedding in it in addition to the Raw bitmap.

Because the computers we use store 8-bits in a byte and it's very awkward to split bytes; 12-bit data is stored using 16-bits, 4-bits are unused.

Bill

Visit me, info and galleries at: Nikon Photos and Information

Small correction here - NEF files actually pack two 12-bit values into three bytes to keep the size of the files down.

Alan.

That's correct, right now no D70 tags are encrypted.

The value is not stored as in Kelvins but rather as ratios of red/green and blue/green.
Mapping this to a Correlated Color Temperature (CCT) is non-trivial so discrepancies are to be expected.
If I were reverse engineering this I would be trying to duplicate the Nikon Capture (NC) values; since this would be the "gold standard".

(Edited to remove an erroneous statement)

Bill

Visit me, info and galleries at: Nikon Photos and Information

It also occurs to me that you might be talking about the discrepancy in the D70 manual page 51 and actual color temperatures.
That subject is covered here Real Color Temperature Values for White Balance

Bill

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"Your selected WB and the 'As Shot' WB are different."

In Capture's WB dialogue, on a Mac, a RAW image taken with WB of cloudy -3 shows "Camera WB:Cloudy -3". In the "New WB" drop down option list, selecting the "Recorded Value" option will restore WB to Cloudy -3.

From this I'm assuming that Recorded Value and Camera WB are the same. Does this mean that "As Shot" is another variable? If so, the "Recorded Value" or "CameraWB" must be stored in another tag - has that tag also been encypted?

Thanks for the link and yes that's the thread I was referring to.

BTW Another current discussion on WB is showing that on some systems Capture displays this same WB setting as "CameraWB:6600"

George

Bali, ID

You're right! I was confused.
I corrected post#4 so people who read it later won't get wrong information.

Thanks!
Bill

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George

Bali, ID

Except for 'Auto' these values come from a table in the firmware.
So another fact is that only the 'Auto' WB is problematic if you respect the encryption.
The other values can be looked up given WhiteBalance and WhiteBalanceBias (tags x05 and x0B respectively, not encrypted).

Bill

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That makes sense. The camera doesn't yet have enough oomph to deduce the CCT from an auto setting so the ratios are stored for computation elsewhere. Capture must be using x05 and x0b as default for WB and only looking at x97 when auto WB is set. That still doesn't explain how RSE, and presumably Adobe, manage to come up with a consistent offset against the camera user's set WB. They can't be using x97 because it will vary from shot to shot and RSE consistently reads a camera set 6600K as 7900K

...scratching head ...unless the firmware table look up, when the user sets WB, also stores associated red/green blue/green ratios in x97, rather than those actually measured. Do you know whether that is the case?

George

George

Bali, ID

x97 always has the 'As Shot' WB.
In 'Auto' it is computed by the camera, otherwise it comes from the table in the firmware.
If you don't have access to x97 then you can use x05 and x0b and a table like the one in the firmware to "get" the 'As Shot' WB value; unless x05 is 'Auto'.

Does this make sense?

Bill

Visit me, info and galleries at: Nikon Photos and Information

George

Bali, ID

Hi Bill,

Thanks for posting this stuff, it's quite interesting. I have a question on custom WB. If one sets a custom WB with a gray card, Expodisc, etc, then I assume that x05 will report 'Custom' and the true value will be recorded in x97. I also assume that there's no way to use the table lookup in the same manner that you appear to be saying will apply to the camera presets. If that is true, then the WB setting with either Auto or Custom are lost, correct?

As a side note, I've seen reports from Australian users that the new D70s appears to have this encryption as well. Have you any information on that?

Thanks.

Kerry

The x97 'As Shot' can only hold one value so if your setting is not 'Custom' then it will not be there.
However, I don't know what the vast majority of the other data in x97 is.
Specifically, I don't know one way or the other whether the 'Custom' setting isn't stored there as well in a different field.

As to the D70s, look elsewhere in this thread; I'm about to make a post

Bill

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Okay, thanks for the info, Bill. I saw your post on the d70s not being encrypted, so at least that is some good news.

Kerry

I've heard that the D2X is hand assembled so it's certainly possible the the innards and shell could match.
But for a mass produced camera, like the D70; that would be hard to achieve.

Thanks for contributing!
Bill

Visit me, info and galleries at: Nikon Photos and Information

x98 is lens information, such as information from your CPU lens.
I'm currently clueless about x91 and the balance of x97.
Maybe someone out there will provide the answer for those!

Bill

Visit me, info and galleries at: Nikon Photos and Information

So, then to summarize.

Photoshop (and any other sw that doesn't decrypt the encrypted data) won't be able to read the 'as shot' WB, lens info (type, focal length setting for zooms - I assume aperture is from the camera body), and some other as yet undetermined info in D2XD2Hs NEF files.

Am I understanding this correctly?

SantaFeBill

Yes, for the D2X.
If unsure about the D2Hs, I have not yet acquired any D2Hs Nefs for testing.
BTW, not all lens information is encrypted; only details regarding CPU lenses.
So LensType, FocalLength, etc. are not encrypted.

Bill

Visit me, info and galleries at: Nikon Photos and Information

Can you be specific about which fact(s) you want documented?

To anticipate...

I have gathered a great deal of "publicly" available information and have also done some of my own investigations.
This information is encapsulated in a "super Exif" program that I use personally.
The output of my program seems correct therefore I believe the underlying facts are correct.

I will not disseminate information that I don't clearly have the right to disseminate.
For example, telling you tag x98 is lens information is benign.
Telling you the layout and meaning of the data in tag x98 might violate Nikon's intellectual property rights.
(Just because someone else already posted it doesn't mean I will).

I hope you will understand.
If I were you I'd be disappointed but that's my position.
(This might also be the Nikonians Terms of Use position depending on how you read it.)

All I can suggest is web searchs for "makernote" AND "Nikon" etc.
And also a reminder than not all the information you find will be correct.

If you want to discuss this further I suggest e-mail rather than posting here.

Regretfully,
Bill

Visit me, info and galleries at: Nikon Photos and Information