View Full Version : raw

05-04-2012, 1:57am
Question hope this is the right place for it thinking about raw files my camera tells me it is 14 bit raw ,but I have also seen other camera which are 12 bit raw ,but a friend tells me that her camera shoots in full raw , which I thought was 12 bit I could be wrong could someone please enlighten me to the difference between 12 , 14 bit and full raw and which is the best so to speak, thanking you .

05-04-2012, 6:27am

12 bits can record a number (remembering that digital files are just made up of bits and bytes - numbers) with 4096 different possible values (2 to the 12th power). Jumping up to 14 bit RAW files gives us 16,384 possible values, or four times as many as that of a 12 bit RAW file.

Where this can come into play, is that 14 bit RAW files can often have more detail in the shadow area of photos. It can also help control the amount of detail in the highlights in your file as well.

The off-set is that 14 bit RAW files generally are at least 25% larger (filesizes) than 12 bit, therefore take up more room on your memory card and take longer to write to the card as well, which for things like fast action sports can slow your camera down. The Nikon D300 has been tested to show that simply changing from 12 bit to 14 bit can change it from 6 FPS to 2.5FPS capture speed.

So if you are a landscaper and want to get the most out of highlight and shadow detail, and capturing at a rate of FPS is not really that important (landscapers tend to set-up, sit and wait, take a shot, recompose, or wait for a change in the light etc), use 14 bit. But if you are a sport photographer and getting a heap of shots off, of an exciting moment in the game is important, stick with 12 bit.

05-04-2012, 9:18am
And as for "full" raw...
Maybe that's something a large lion does, but I've never heard of the term before. It sounds more like hype than anything specific.
The question is, Where do you stop? OK, Adobe Photoshop CS6 can read 32-bits-per-channel files, but what camera produces that? I suspect it's for CMYK files.

For comparison, a jpeg file can only hold 8 bits per channel, or 256 tones per R G and B channel. So if you're shooting jpeg only in the camera, you are compressing all the tonal information into narrower bands.
If you had a range of colours, like in a rainbow, a jpeg could not distinguish between and record as many hues as could a 12- or 14-bit raw.

06-04-2012, 12:49am
thanks for the info with use it wisely

06-04-2012, 2:29pm
I suppose you could use the term 'full raw' for an uncompressed 14bit raw file, and the term 'less than full raw' for a compressed 12bit raw file! :p

Seriously as Rick pointed out raw is raw and the reason some manufacturers offer a 12 bit mode is that the file sizes are smaller for quicker camera response/shooting and the reality is that 99.999% of people will not really ever see the difference of those last two bits of data info(usually at the highlight end of the scale).

If you are shooting for high end fine art type purposes, then you shoot shoot in 14bit mode.

The same reasoning applies to compressed raw as for 12 vs 14 bit raw mode. The compression is kind of like the conversion to jpg, where some data is lost, but the manufacturer compresses the highlight part of the scene. This area of data is almost certainly insignificant to the average punter, so you could use some compression on your raw file for better speed and data storage. The same high end usage caveat applies to compression of raw files as it does to the bit rate too.

With some older cameras(that I only know of Nikon and possibly Sony models) if you choose 14 bit mode over 12 bit mode, your camera's fastest frame rate can drop significantly(it's a property of the sensor).
D300 can achieve 6fps or 8fps in 12 bit mode, but only about 1.5fps in 14bit mode, no matter if the battery grip is used or not. The sensor's output path is the limitation in 14 bit mode. D3x has the same issue, and they both use a Sony designed sensor.
From what I know of the D7000, which is a far newer model, and which also uses a Sony sensor, it can shoot at the same frame rate irrespective of bit mode chosen.

Because of the fps limitation I generally shoot in 12 bit mode on my D300, and will choose 14bit mode if I'm shooting landscapes.

08-04-2012, 4:57am
thanks I mostly asked cause a friend told me that I didn't have full raw cause it said 14 bit raw she thought it was lesser .I will more then likely shoot in 12 bit mode fort he faster speeds but it is good to know there is a bit extra there for landscaping and stuff as mention probably wont tell the difference between the two ,and most of my shoots are in jpg at eh moment but I have the option there to use in the future as I become more involved ,not sure if I want the extra work load though that raw brings with all photos needing post processing

08-04-2012, 7:36am
Some cameras shoot less fast (fps) in 14 rather than 12

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Mark L
08-04-2012, 9:31pm
....,and most of my shoots are in jpg at eh moment .......,not sure if I want the extra work load though that raw brings with all photos needing post processing

You can take your photos using both. Then when, later as you learn, or when that stunning image happens, you've got the raw to extract more!

08-04-2012, 9:49pm
Lycan. I'm sure you won't look back when you start enjoying the rewards from the bit of extra work processing raws.