Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Nikon dSLR

Reply
 
Thread Tools Search this Thread
Old Dec 23, 2012, 11:45 AM   #1
Senior Member
 
Wingman's Avatar
 
Join Date: Dec 2003
Location: Hebron, Kentucky (northern Kentucky/Greater Cincinnati):KCVG
Posts: 4,327
Default D300s (12 Bit vs 14 Bit)

So...what's the practical difference between 12 bit RAW vs 14 Bit RAW? Reason for my question is that when I set my D300s to capture 14 Bit Raw, the shutter sounds like it operates slow. I read on some on-line forums that changing to 12 bit RAW eliminated this issue...which it did.

I'm now interested to know what it means to IQ if any

Any thoughts?

Jehan
Wingman is offline   Reply With Quote
Sponsored Links
Old Dec 23, 2012, 3:30 PM   #2
Senior Member
 
TCav's Avatar
 
Join Date: Sep 2005
Location: Washington, DC, Metro Area, Maryland
Posts: 13,572
Default

RAW files are a record of the luminance detected by each photoreceptor. RAW files do not contain any color information.

Most cameras use a Bayer Filter over the image sensor to allow each photoreceptor to detect the luminance of a certain color of light, either Red, Green, or Blue. There are twice as many photoreceptors detecting green light than there are detecting red or blue light. Because of the layout of the color filters in a Bayer filter, and in order to map color values for each of the three colors to each pixel, the values for each color at each pixel for which the corresponding photoreceptor didn't collect, are interpolated from adjacent photoreceptors that did.

So each green photoreceptor contributes 1/4 of its value to each of the 4 adjacent pixels whose corresponding photoreceptors detected either red or blue. In that way, green is well represented in the image because 1/2 of all photoreceptors detect green light. But the values for red and blue are spread more thinly. Each red photoreceptor contributes 1/2 of its value to each of the 4 adjacent pixels whose corresponding photoreceptors detected green, and 1/4 of its value to the 4 pixels at each corner whose corresponding photoreceptors detected blue. The same is true for each blue photoreceptor, which contributes 1/2 of its value to each adjacent green pixel and 1/4 to the 4 red pixels at each of its 4 corners. As a result, details in red and blue objects are less well represented than details in green objects.

This is why advertisements for Sigma's digital cameras, which do not use Bayer Filters, are filled with photos featuring lots of detail in objects that are not green.

Remember that color information is very much diluted in the process of assigning red, green, and blue color values to each pixel, so the more nuances that are preserved, the better. A 14 bit RAW file contains 16384 discrete values for luminance for each photoreceptor, whereas a 12 bit RAW file contains only 4096 discrete values, so a 14 bit RAW file will preserve more nuances in color and detail than a 12 bit RAW file, especially for red and blue.
__________________
  • The lens is the thing.
  • 'Full Frame' is the new 'Medium Format'.
  • "One good test is worth a thousand expert opinions." - Tex Johnston, Boeing 707 test pilot.

Last edited by TCav; Dec 23, 2012 at 7:43 PM. Reason: sp
TCav is offline   Reply With Quote
Old Dec 24, 2012, 6:17 AM   #3
Senior Member
 
zig-123's Avatar
 
Join Date: Dec 2006
Location: Cape Cod, Massachusetts
Posts: 5,157
Default

Thanks TCav, for that very detailed explanation.

After reading your response, I started to dig into my manuals and it opened my eyes to some of the other important settings I was overlooking.

14bit lossless compression is one of the more important settings that, up until now, I had not paid much attention to.

Zig
__________________
http://scortoncreekgallery.smugmug.com/

So you want to be a better photographer? Open your eyes and take a look at what is all around you.
zig-123 is offline   Reply With Quote
Old Dec 24, 2012, 9:23 AM   #4
Senior Member
 
Wingman's Avatar
 
Join Date: Dec 2003
Location: Hebron, Kentucky (northern Kentucky/Greater Cincinnati):KCVG
Posts: 4,327
Default

Indeed, thanks for the detailed explanation.

Zig, be advised though that using 14 Bit Raw slows your burst rate down to 2 FPS...may not be suitable for BIF shots.

I've been experimenting with RAW for my aviation photography and discovered the issue of the slow burst rate at 14 Bit compared to 12 Bit. To my eyes for images resized to 1200 pix wide, I cannot see a difference. I'm waiting to see if the screeners at airliners.net notice a difference.

Jehan
Wingman is offline   Reply With Quote
Old Dec 24, 2012, 9:45 AM   #5
Senior Member
 
zig-123's Avatar
 
Join Date: Dec 2006
Location: Cape Cod, Massachusetts
Posts: 5,157
Default

Quote:
Originally Posted by Wingman View Post
Indeed, thanks for the detailed explanation.

Zig, be advised though that using 14 Bit Raw slows your burst rate down to 2 FPS...may not be suitable for BIF shots.

I've been experimenting with RAW for my aviation photography and discovered the issue of the slow burst rate at 14 Bit compared to 12 Bit. To my eyes for images resized to 1200 pix wide, I cannot see a difference. I'm waiting to see if the screeners at airliners.net notice a difference.

Jehan

Hi Jehan,

Up until now, I have used 12bit RAW lossless compression as my default setting. And, for the most part, it has worked quite well. But, I do a fair amount of landscape and static photography, so fps is not a factor. It is this area, that I have great interest in improving.

I did some quick testing this morning. While not conclusive, the detail and depth of color seemed improved- By that I mean the color needed no adjustment-something that I regularly do in CS6. Now, it's time to go out and try it seriously on some landscape shots and compare results.

Zig

Zig
__________________
http://scortoncreekgallery.smugmug.com/

So you want to be a better photographer? Open your eyes and take a look at what is all around you.
zig-123 is offline   Reply With Quote
Old Dec 24, 2012, 10:26 AM   #6
Senior Member
 
TCav's Avatar
 
Join Date: Sep 2005
Location: Washington, DC, Metro Area, Maryland
Posts: 13,572
Default

A 14 bit RAW file contains room for 4 times the data for each photoreceptor, so a 14 bit RAW (uncompressed) file should be about 4 times the size of a 12 bit RAW (uncompressed) file. That should explain the reduced continuous frame rate. (The previous, italicized passage is not correct. Please ignore it.)

It's important to remember that few monitors are capable of displaying the added color and detail that a 14 bit RAW file has over a 12 bit RAW file. The real test is in the printing. But the printer's real resolution and the amount of upsampling the driver performed when printing the RAW file, can reduce the apparent difference.

Basically, if you can handle the slower frame rate and additional storage requirements, 14 bit RAW is worth the effort on the rare occasion when it will make a real difference. But if all you're doing is creating images that will only ever be displayed on a TV or computer monitor, then there's no real benefit.
__________________
  • The lens is the thing.
  • 'Full Frame' is the new 'Medium Format'.
  • "One good test is worth a thousand expert opinions." - Tex Johnston, Boeing 707 test pilot.

Last edited by TCav; Dec 30, 2012 at 10:06 AM. Reason: Removing error
TCav is offline   Reply With Quote
Old Dec 24, 2012, 10:49 AM   #7
Senior Member
 
zig-123's Avatar
 
Join Date: Dec 2006
Location: Cape Cod, Massachusetts
Posts: 5,157
Default

Quote:
Originally Posted by TCav View Post
A 14 bit RAW file contains room for 4 times the data for each photoreceptor, so a 14 bit RAW (uncompressed) file should be about 4 times the size of a 12 bit RAW (uncompressed) file. That should explain the reduced continuous frame rate.

It's important to remember that few monitors are capable of displaying the added color and detail that a 14 bit RAW file has over a 12 bit RAW file. The real test is in the printing. But the printer's real resolution and the amount of upsampling the driver performed when printing the RAW file, can reduce the apparent difference.

Basically, if you can handle the slower frame rate and additional storage requirements, 14 bit RAW is worth the effort on the rare occasion when it will make a real difference. But if all you're doing is creating images that will only ever be displayed on a TV or computer monitor, then there's no real benefit.
Good points, TCav,

I regularly sell landscapes as large as 13 x 38 that have been printed on an Epson 4000. It is for this reason that whatever last bit of detail and color I can
pull out would be worthwhile.

Zig
__________________
http://scortoncreekgallery.smugmug.com/

So you want to be a better photographer? Open your eyes and take a look at what is all around you.
zig-123 is offline   Reply With Quote
Old Dec 24, 2012, 1:09 PM   #8
Senior Member
 
TCav's Avatar
 
Join Date: Sep 2005
Location: Washington, DC, Metro Area, Maryland
Posts: 13,572
Default

Quote:
Originally Posted by zig-123 View Post
I regularly sell landscapes as large as 13 x 38 that have been printed on an Epson 4000. It is for this reason that whatever last bit of detail and color I can pull out would be worthwhile.
Amen to that.
__________________
  • The lens is the thing.
  • 'Full Frame' is the new 'Medium Format'.
  • "One good test is worth a thousand expert opinions." - Tex Johnston, Boeing 707 test pilot.
TCav is offline   Reply With Quote
Old Dec 25, 2012, 9:56 AM   #9
Senior Member
 
TCav's Avatar
 
Join Date: Sep 2005
Location: Washington, DC, Metro Area, Maryland
Posts: 13,572
Default

I did this just to make it clearer to myself. What do you think?
Attached Images
 
__________________
  • The lens is the thing.
  • 'Full Frame' is the new 'Medium Format'.
  • "One good test is worth a thousand expert opinions." - Tex Johnston, Boeing 707 test pilot.
TCav is offline   Reply With Quote
Old Dec 26, 2012, 7:27 AM   #10
Senior Member
 
zig-123's Avatar
 
Join Date: Dec 2006
Location: Cape Cod, Massachusetts
Posts: 5,157
Default

I'm dizzy just looking at it.

Zig
__________________
http://scortoncreekgallery.smugmug.com/

So you want to be a better photographer? Open your eyes and take a look at what is all around you.
zig-123 is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 7:40 PM.