How do you take advantage of 12 bit NEF image?

How do you gain from a 12 bit NEF image if you can only work with it after it is converted to an 8bit TIF?

You record this great raw file but you never get to see the 12bit color.Correct me if I am wrong but aren't monitors limited to 8bit(per channel) color? Are there printers that can show 12 bit color?

How does the 12bit raw color translate into useable data?

Don Terrana

don Terrana said:

How do you gain from a 12 bit NEF image if you can only work with
it after it is converted to an 8bit TIF?

Click to expand...

When you load the picture in photoshop it stays 12bit all the time you work on it you can then decide if is time to save it at 8 bit or 12 depending on the format you choose.

Gabriele

don Terrana said:

How do you gain from a 12 bit NEF image if you can only work with
it after it is converted to an 8bit TIF?

You record this great raw file but you never get to see the 12bit
color.Correct me if I am wrong but aren't monitors limited to
8bit(per channel) color? Are there printers that can show 12 bit
color?

How does the 12bit raw color translate into useable data?

Don Terrana

Click to expand...

Deon,

You can work levels, curves, and other things in PS at the 16 bit level before having to drop to 8 bits. (Note: anything over 8 bits is treated by PS as a 16 bit file.) The advantage is that when "pushing pixels around" with these tools, you can run out of pixels if the file is only 8 bits, where 16 bits gives you more headroom to make your corrections.

Ron

don Terrana said:

How does the 12bit raw color translate into useable data?

Click to expand...

Hello Don Terrana!

You are right in your assumption on 8-bit for Monitors an 12 Bit for NEF.

Shooting TIFF eats up a whopping 17,4 MB of CF - card space. NEF is only about 10 MB. Using the NEFs is best with Nikon Capture, where you can use the "extra" 4 Bit per Color to correct Exposure, White Balance, etc. After saving the result as TIFF, you have a pretty good working file for Photoshop. Without Capture and only Nikon View its just a way to maintain best available quality without using to much space. Just open the NEF in View, try some of the very limited corrections and save as TIFF. Its a better way of using TIFF with only 9.6 MB.

So, conclusion: If you own some 10+ Microdrives, and do not own Capture: shoot TIFF.
If you have Capture: shoot NEF.

nt

12-bit is usable in Capture or in Photoshop as a 16-bit TIFF (you have to select the 16-bit option). In theory 12-bits of information give you 4096 shades for each Red, Green, and Blue channel compared to 256 for 8-bit. In reality the numbers are less due to noise. Most monitors and printers are 8 bit and I am not even positive if the human eye can see 12-bit differences (I could be wrong). The advantage comes from post processing with all the extra data. This page can explain it a little better: http://www.outbackphoto.com/handbook/digitaldarkroombasics.html

don Terrana said:

How do you gain from a 12 bit NEF image if you can only work with
it after it is converted to an 8bit TIF?

You record this great raw file but you never get to see the 12bit
color.Correct me if I am wrong but aren't monitors limited to
8bit(per channel) color? Are there printers that can show 12 bit
color?

How does the 12bit raw color translate into useable data?

Don Terrana

Click to expand...

If you do more than 1 colour change in 8 bit mode, something called clipping may occur and the end result will be less refined than working in 12/16bit. But it's very subtle. You might see it if you've done 12 colour changes. (colour balance, levels, curves, channel mixer, fading all these changes) Whenever I see it, I always see it in the dark areas.

Even if you start with an 8 bit Jpeg, converting to 16 bit makes sense (Photoshop help file)

You'll probably find more information if you do a search in the retouching forum.

Bart

don Terrana said:

How do you gain from a 12 bit NEF image if you can only work with
it after it is converted to an 8bit TIF?

You record this great raw file but you never get to see the 12bit
color.Correct me if I am wrong but aren't monitors limited to
8bit(per channel) color? Are there printers that can show 12 bit
color?

How does the 12bit raw color translate into useable data?

Don Terrana

Click to expand...

Wolfgang58427 said:

So, conclusion: If you own some 10+ Microdrives, and do not own
Capture: shoot TIFF.
If you have Capture: shoot NEF.

Click to expand...

I'd have to disagree somewhat, Wolfgang. If you have Photoshop but not Capture (or Bibble or QImage, both of which also post-process NEFs), you can still have an advantage to shooting nefs. They have all the raw 12 bit data, but are only half the size of tifs, and if you have Nikon View, there is a plugin that will allow you to open the nef files directly in PS. Thre is really no reason to shoot tif any longer from what I can tell...

Ron

bartP said:

Even if you start with an 8 bit Jpeg, converting to 16 bit makes
sense (Photoshop help file)
You'll probably find more information if you do a search in the
retouching forum.

Bart

Click to expand...

I made that discovery some time ago. I would use a 250 pixel feather to "burn down" the edges of my portraits on the 8 bit scans my lab would make from 120 negs, and I began to notice some faint posterization at times. When I converted to 16 bit to make the same enhancement, no more posterization! Now, even after I have to convert to 8 bits so I can do cut & past or use levels, I usually go back to 16 bit to do gaussian blur or feathered selections.

Ron

CoryC said:

12-bit is usable in Capture or in Photoshop as a 16-bit TIFF (you
have to select the 16-bit option). In theory 12-bits of information
give you 4096 shades for each Red, Green, and Blue channel compared
to 256 for 8-bit. In reality the numbers are less due to noise.
Most monitors and printers are 8 bit and I am not even positive if
the human eye can see 12-bit differences (I could be wrong). The
advantage comes from post processing with all the extra data. This
page can explain it a little better:
http://www.outbackphoto.com/handbook/digitaldarkroombasics.html
Dear Cory,

Click to expand...

Thanks very much for your reply. Your explanation is vwry helpfull.
Don Terrana

CoryC said:

PS. my sincere thanks to everyone who answered my questions.I really appreciate your efforts

don Terrana said:

How do you gain from a 12 bit NEF image if you can only work with
it after it is converted to an 8bit TIF?

You record this great raw file but you never get to see the 12bit
color.Correct me if I am wrong but aren't monitors limited to
8bit(per channel) color? Are there printers that can show 12 bit
color?

How does the 12bit raw color translate into useable data?

Don Terrana

Click to expand...

Click to expand...

Don,

don Terrana said:

How do you gain from a 12 bit NEF image if you can only work with
it after it is converted to an 8bit TIF?

Click to expand...

You import the image as a RAW file into Nikon Capture or into Photoshop using the plug in as a 16 bit file. You make your adjustments to tone , saturation , WB ..etc. and then save the high bit optimized image into a lowbit space (8) format like jpg or TIFF. This ensures that posterization of color values in the original data does not occur and allows you very fine grained control of the various gradiations in your original image. It also allows you more latitude for fixing exposure flubs than shooting in a low bit space to begin with. Here's a tutorial on high bit processing, Photoshops help is also a very good source:

http://www.btinternet.com/~ian.lyons/16bit/16bit_1.htm

don Terrana said:

You record this great raw file but you never get to see the 12bit
color.

Click to expand...

Maybe ..maybe not ..read on.

don Terrana said:

Correct me if I am wrong but aren't monitors limited to
8bit(per channel) color?

Click to expand...

Monitors are limited to what the video card can provide as far as discrete colors available from a pc, but most consumer monitors also have an 8 bit variation in the R, G and B values that the electron guns can excite from the phosphor dots in the CRT's shadow mask. A monitor is an analog device, the phosphor dots used in the shadow mask on a CRT can have a very large gamut depending on the gradation of excitation caused by the electron beams. A few links:

http://www.cg.tuwien.ac.at/research/theses/matkovic/node24.html

http://www.cg.tuwien.ac.at/research/theses/matkovic/node22.html

Most video cards shipping today can provide 24 bit as well as 32 bit color (mine does), but if you have an 8bit RGB CRT it doesn't matter you'll only see 24bit color on screen, additionally weather your eye can even discern the difference in so many hues is still not exactly a fact. (Some claim they can see differences, some can't..)

don Terrana said:

Are there printers that can show 12 bit
color?

Click to expand...

Maybe, different printers depending on the inks and dyes used to produce the print have different output gamuts..just like your camera does (sRGB, AdobeRGB..etc) and your monitor does. The dye sub and color laser printing methods will most likely have the highiest output gamuts in comparison to say inkjet printers, you can probably find detailed research on this on the net. Here's one from google.

http://www.kodak.com/US/en/corp/researchDevelopment/technologyFeatures/gamut.shtml

don Terrana said:

How does the 12bit raw color translate into useable data?

Click to expand...

I'll need a bit more clarification on this question before I can answer.

Hope that helps,

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