Why 40D Raw smaller files than TIFF from Nikon?

[derrickdehaan]

We just got married on July 4th. Over our wedding/vacation, I took many photos with my Canon 40D. Now my 40D

shoots RAW files that range 11-13MB per photo. A friend shot our wedding and said he would shoot in TIFF files

from his Nikon D100. After getting the digital files from our friend, I was amazed that these Tiff files were so big. The

files are 17.2MB per photo from 3008 x 2000 6mp camera. I guess my question is, is there that much more info on

those Nikon Tiff files over my Canon RAW files?

 

Thanks,

 

Derrick

[John Crowe]

Now convert your RAW files to 16 bit tiff files through your Canon software or Photoshop. There you go you now have way more info than a 6 MP camera. So, no, your RAW files are superior.

[peter_daalder]

The Nikon Tiff files most likely started off as NEF files, which were then converted to Tiffs.<p>You can do the same with your Canon RAW files and obtain even 'larger' Tiff files than your friend.<p>Open them up with Canon's DPP. It should have come with your camera...

[John Crowe]

The reason he likely gave you tiffs is because they are much easier to print at home or at a store. It is also easier for him to have done some Photoshop work with them in tiff format before saving them for you. I keep a copy of my RAW and NEF files as the "negatives" and convert them to tiffs for editing, printing and viewing purposes. Then I reduce these tremendously in size and convert to jpegs for emailing or posting here on photo.net.

[derrickdehaan]

Thanks folks. Guess I never had converted any of my canon images to tiff long enough to see how large of a file they were. Thanks again.

 

Derrick

[chrisjb]

Tiffs should be lossless files, so you can still fine tune without loosin Q, sounds like 8bit tho. From a wedding just finished with 40d our tiffs average bout 58meg :)

[derrickdehaan]

Chris...my 40 TIFFs are 58meg as well. So my new question is...why are Tiff files larger than RAW. Obviously everything on a TIFF is in the RAW file. What makes them suddenly larger files? Just curious now.

 

Thanks,

 

Derrick

[JosvanEekelen]

Probably because TIFFs are 16 bit, adding several 0-s for the least significant bits whereas a proprietary file format like the ones Canon (and Nikon) use just skip this information and record 12 or 14 bits of info.

[rainer_t]

-- "What makes them suddenly larger files?"

 

You should investiage how digital sensors record the light and try to understand how the "bayer matrix" works ... then you would find, that raw files contain pixels with just one color, the reslting tiff file has the missing two other colors per pixel) already interpolated. This step of "developing" a raw file doesn't produce new information out of nowhere, but it changes the size of the resulting image file nevertheless.

[frank_ernens]

Although information is measured in bits and file size is also measured in bits (well, multiples of 8 bits), they are not the

same thing. For example, if I write a single letter A to Z in a computer file I will probably use 8 bits to do that - but there is

only between 4 and 5 bits of information there, because 26 is between 16 and 32.

[ShunCheung]

Derrick, I have a Nikon D100 from way back in 2002. It is a 6MP DSLR and its uncompressed RAW files are about something like 9.8M bytes each.

 

Any 17M-byte TIFF file from the D100 probably just has a lot of filler without any real additional information. That is why very few people use the TIFF mode because it merely takes up space.

In these days it is primarily for law-enforcement and legal applications.

 

Congrats on your wedding.

[apetty]

"Chris...my 40 TIFFs are 58meg as well. So my new question is...why are Tiff files larger than RAW."

 

RAW is a loss less compression. TIFF is not compressed at all.

[frank_ernens]

Adam Petty wrote:

<p>

<i>TIFF is not compressed at all.</i>

<p>

TIFF does allow for lossless compression. Even if the Nikon uses that, the TIFF will still be larger for the reason Rainer gave.

[chrisjb]

G`day, as quite often answers can be found on the PN site as such

 

http://www.photo.net/learn/raw/

 

while it is basic even ol folks like myself still find time to learn, following further is up to each, the analog/digital converter is 14bit so would account for a gigher file size?

 

When I managed a photo store I found that by spending extra time to explain how cameras worked and the componants to achieving a good photo, those folks were the ones who kept coming back with enthusiasm and smiles. those that just bought and went off were never happy. That was in film days, digital and the net makes it easier to learn how all processes click together. Understanding as much as possible gives more control to the user, happens with all things I guess most women don`t understand car engines just as men don`t know sewing machines, this makes certain task harder to do either way

 

Have fun :)

[onewish]

TIFF files have 24 bits per pixel, or 3 bytes. 6M pixel * 3 bytes / pixel = 18M bytes.

RAW files have 14 bits per pixel and are lossley compressed, say 1.3 bytes. 10M pixel * 1.3 bytes / pixel = 13M bytes.

 

I hope that explains the file size difference.

 

To answer your question of which file has more information, the RAW files have more information in less bytes than the Nikon TIFF. Canon and Nikon sensors record one color per pixel and interporlate the other 2 colors to create a jpeg or tiff file. Ignoring the interpolated data, the TIFF files provide 6MP at 8 bits per pixel, compared to 10MP at 14 bits per pixel with RAW.

[arie_vandervelden1]

Like Yoav says. RAW files have 14 bits per pixel, representing either blue, red, or green. Normal TIFF files have 8 bits for red, green and blue, a total of 24 bits per pixel. 16-bit tiff files have 16 bits each for red, green and blue, for a total of 48 bits per pixel.

 

RAW files have lossless compression. Normal TIFF files often have lossless compression (typically the lempel-ziv scheme). I can't get Photoshop to compress my 16-bit TIFF files - they're saved without compression and they're huge.

 

Some typical file sizes out of my XTi - 8 Mb RAW, 14 Mb TIFF, 64 Mb 16-bit tiff.

[ted_marcus1]

When I tried the LZW compression option for 16-bit TIFFs in Photoshop, the result was larger than uncompressed TIFFs. The only truly effective compression I've found for 16-bit files is lossless JPEG 2000, which can reduce the file size by up to 30%. That needs a plug-in manually installed from the CD or DVD, and its performance is excruciatingly slow.

[frank_ernens]

Ted, you inspired me to do some testing using Photoshop CS3 (version 10.0). It turns out Adobe are using horizontal differencing (TIFF

tag 0x13d is 2) for 8-bit LZW but not using it (tag is missing, defaults to 1) for 16-bit LZW. Hence the "compressed" file

actually is bigger for photographic images, exactly as you said. ("Differencing" means that what is compressed is the

difference between adjacent R, G or B values rather than the values themselves.)

 

That arithmetic-type compression like LZW is useless for photographic images if you don't use differencing should have

been obvious to whoever wrote Adobe's code, but just in case it wasn't the TIFF standard goes to the trouble of pointing

it out on page 65.