Dr.db Loc: Central Point, OR

If this is a question, the answer is: yes, each one is a better file, for some purposes, and has its place in a proper workflow.

Wish I weren't late to this discussion, but I was out getting bear scat on my shoes (maybe a preferable experience? ;-) )

At the risk of offending somebody, I must say that with the exception of a few posters, the amount of misinformation and folklore being spewed on this thread seems high above even the usual static level for this type of discussion on UHH. You go, gang, show everybody what you know (or not)... :thumbup: - How about another list of items for consideration?

- PNG is not an "Adobe format" (Wikipedia is your friend.)

- Wendy, I get the feeling you are confusing TIFs with PSDs. If not, can you enlighten us how it is that you can reopen a TIF file and "undo" some edit you did in the past? - I would love to know that trick.

- Apaflo had it right about LZW compression on TIFs - betcha can't give me one good reason NOT to use it.

- For fun, I MUST mention that for several years I used a Canon 1Ds (the original), and its output file format for RAW images WAS .tif. And if I drag one of those TIF files into Photoshop, it opens with Camera Raw by default, and IS a bloody RAW file, with no steenking CR2, NEF, DNG or what-have-you for unnecessary and redundant translation. I wonder why Canon and other manufacturers did not continue on that path? (That's right, it's about the $$$, of course...)
I have a few of those TIFs here, if anybody cares to prove me wrong...

- And one other thing while I'm ranting... I see lots of posts about sending various file formats to commercial printers, but nobody ever mentions PDF for that. But that's the file format which shows a printer you might actually have your s**t together a bit, because you, the customer, in creating your PDF have already finalized the printing decisions about page size and trimming, placement of the image on the page, resolution and colorspace profiles, and etc. When I send a file to my printing company, if it's a TIF, they will have a list of questions about that stuff - if it's a PDF, they say, "okay!" and print it, looking exactly like I already knew it would.

LoneRangeFinder Loc: Left field

FWIW: Some DSLRs do allow shooting in the TIFF format: my old D300 does; my much newer D7100 does not. The TIFF files are roughly twice the size of NEF (raw).

marcomarks Loc: Ft. Myers, FL

You apparently aren't aware that if you open a JPG in Photoshop that it also opens in ACR first, but that certainly doesn't prove it's a TIFF or RAW file - so ACR opening is not a verification that TIFF is RAW or RAW is TIFF. But if you read about RAW in Wikipedia you'll find that the original RAW format by Adobe (DNG) was a variation on the TIFF format. Then proprietary RAW formats started replacing DNG - with a few manufacturers staying with DNG. Now THAT does verify that layered TIFF, DNG, and proprietary manufacturer RAW formats are kissing cousins.

Wendy is not confused but correct if she's saving as a layered TIFF. Layers can be removed or changed after the fact there just like a Photoshop PSD file. Sorry about your lack of knowing such things.

Try to get your facts straight before spewing your misinformation and folklore in the static zone.

jcboy3

I refer to the Wikipedia post on "Raw image format" at

http://en.wikipedia.org/wiki/Raw_image_format

Hence, the Raw file is an image file.

I refer to the Cambridge in Colour post on "Digital Camera Sensors" at

http://www.cambridgeincolour.com/tutorials/camera-sensors.htm

wherein they refer to photosites and pixels of the sensor data.

While there are numerous algorithms for demosaicing the sensor data, that does not change the fact that it is an image. Perhaps you can provide a source for your statement that image data defines just exactly one single image.

On the other hand, if I use Lightroom to view a RAW file, then there is in fact a unique image based upon the demosaicing algorithm used by Lightroom. There is no random event; I will get the same result every time. So in that case, there is exactly one single image associated with that file.

The derivation of an RGB image for display purposes is the same for all image formats. JPG files are compressed and must be converted for viewing. TIFF files can be compressed, and can be higher resolution than supported by displays. So it's all the same, nothing unique about the RAW file. The ONLY difference is that an image is not saved as a RAW file; it's only used for input.

As far as WB, well what can I say. The "as shot" WB is a fact, it comes from the RAW file; it is preserved in a DNG file. It is not a "default" value but is set by the camera. Might be constant if the WB mode is set (e.g. "daylight"), but if auto WB is used, or a custom WB is set in the camera, or if WB is adjusted in camera, then the value will be what is used by the camera to create a JPG.

WB is in the data. Experiment. Change settings in your camera; look at the "as shot" WB in your editor, change it in your editor and export the file as DNG and other formats and see what happens when you re-import. It's all there to discover. No amount of dogmatic pronouncement will change this.

The difference between WB adjustment for JPG and TIFF can also be easily demonstrated. If I adjust WB and export to TIFF, then when I re-import the image the adjusted WB will be displayed as an "as shot" value. For JPG, however, the WB setting is not preserved and the "as shot" value will show 0 for both temperature and tint. That is clearly a difference, as I was stating.

I am aware that raw file formats are based upon the TIFF/EP format, as is the DNG format. As stated in

http://en.wikipedia.org/wiki/TIFF/EP

But that is irrelevant, since most software written to process TIFF image files do not process RAW files.

Regards.

Wendy2 Loc: California

Do you use CS or the cloud? If you save a file in Tiff format, when you reopen it, it will contain all the editing you did. Tiff and PSD files work the same way, but the Tiff file is smaller.

I do this kind of editing on a daily basis. I used to save the files to PSD but learned from many instructors on CreativeLive.com that that is not necessary. That Tiff files work just as well as PSD, but take up less space or memory.

Apaflo Loc: Anchorage, Alaska

And just because you found it on the Internet, it's true?

Cambridgeincolor often uses language very imprecisely. They really should fix that! Wikipedia is well know for inaccuracy. Here is what that article says (analyze this for logic, rather than content):
IOW, it's not an image after all.


Invalid logic, but that isn't the point anyway.

There are numerous images that can correctly be generated from any given RAW file with any given algorithm. They all represent a valid application of that given algorithm. (And that it is not a reversible process, in that none of the images can be used to re-generate the RAW file.)


Perhaps you can provide a source that says otherwise. Isn't it inherent in every image standard and every definition of "image"? An image is an image, not a collection of images.

Or more to the point, each pixel has exactly one location, one tone level, and one color value. And each pixel is unique, it affects those values for that one location in the image and does not affect any other location. That is, as a set, the pixel data absolutely defines an image. Just one image. Anything that changes the image is either an edit or an error.

Compare that to raw sensor data. Each sensor location value affects multiple pixels of any generated image. None of the values is unique to any pixel. And no set of values for one location actually defines the location, the tone level or the color value for that location in a resulting image generated from the raw data. And when correctly processed there can be many different and each quite correct images produced.


That is not true. Lightroom can show you thousands of distinctly different images, each derived from the exact same raw sensor data, and each image is "correct". You will only get the same result every time if you tell it you want that one single result. That doesn't make the other incorrect, and the others do not require editing the raw sensor data to get a different result.

With an image file there is only one way to display the data correctly. Anything else necessarily means the data is edited. (Not that every display provides exactly the same image, but that is the intension and the differences can be measure and are "errors" in display.)


JPEG and other images, not just TIFF images, can also be higher resolution than supported by displays. The image format has nothing to do with resolution.

RAW files are clearly different than image files. The data necessarily must be processed to generate an RGB image. The data does not define just one RGB image. Without editing the data there are many possible RGB images. But once an RGB image is formed, it is just one image and any change requires editing the image data to display something different.


WB data that is in the RAW file has not been applied to the raw sensor data. That particular WB data need not ever be applied! It is used as the default by some RAW converters, but even with those the default can be changed to virtually any valid WB setting.

Whatever WB data is in the RAW file is just non-essential metadata. Your RAW converter can totally ignore it with no consequence.


No need to experiment, I've looked at the source code to the RAW converter that I use (and a couple others).

The raw sensor data is not affected, ever, by WB. It isn't until the RAW converter generates RGB image data that WB is applied. And if that is then changed, while still working with a RAW converter, the entire RGB data set that had already been adjusted for WB will be discarded, a totally new data set generated from the raw sensor data, and only then will WB be once again applied.

It is, at that stage, never converted from one WB adjustment to another. But if it is saved to a file or otherwise transfered to an editor that does not have access to raw sensor data, any change to WB is necessarily an adjustment to what exists. That has a very different effect too, due to the artifacts created at lower bit levels.

Essentially, you really do not want to change WB of an 8-bit JPEG if there is any way to avoid it. Less important with a 16-bit TIFF, but even then it is best avoided.


Clearly an artificial distinction between what your editor shows for one and what it shows for the other, and not a distinction between how WB is applied to either type of file.

At the point when WB is adjusted in an editor the data being worked on is not in either JPEG or TIFF format, but rather in the internal RGB format of the editor. After WB is applied to the RGB data it can be written to a file in either JPEG or TIFF format, which will not change WB.

jcboy3

I'm going to keep it simple this time.

Perhaps you will consider what the Nikon web site says about the NEF format:

http://www.nikonusa.com/en/Learn-And-Explore/Article/ftlzi4ri/nikon-electronic-format-nef.html

"Exclusive to Nikon cameras, the NEF is Nikon's RAW file format. RAW image files, sometimes referred to as digital negatives, contain all the image information captured by the camera's sensor, along with the image's metadata (the camera's identification and its settings, the lens used and other information). The NEF file is written to the memory card in either an uncompressed or "lossless" compressed form.
The primary benefit of writing images to the memory card in NEF format rather than TIFF or JPEG is that no in-camera processing for white balance, hue, tone and sharpening are applied to the NEF file; rather, those values are retained as instruction sets included in the file. You can change the instruction set as many times as you like without ever disturbing the original image's RAW data. Another benefit of the NEF file is that depending on the camera, it retains 12-bit or 14-bit data, resulting in an image with a far greater tonal range than an eight-bit JPEG or TIFF file.
After-capture processing of the NEF file by Nikon's Capture NX2 software, or other imaging programs, offers greater control over the final image than the processing of a JPEG or a TIFF. After processing, the NEF file can be saved as a TIFF, JPEG or again as a NEF with the addition of any applied Capture NX2 processing saved inside the file as a second or alternate instruction set. As long as the original NEF file is preserved, the "digital negative" remains untouched; processing a NEF file does not alter the original instruction set."

And just one other point. Perhaps WB data stored in the RAW file is non-essential to you. But I do set custom white balance with white or gray cards or ExpoDisc, and the preservation of that data is essential for my RAW data processing. Because the sensor image data is not changed, I need the WB metadata to be preserved and used to correct the image in post processing.

Apaflo Loc: Anchorage, Alaska

This is much like your citing Wikipedia and Cambridgeincolour, where they simply did not say what you claim!


Note that while this refers to "RAW image files" it does not refer to the sensor data as an image. It's an image file. And there are multiple JPEG formatted images in each NEF file, as well as raw sensor data.


The only image it refers to is produced by processing the NEF file. And note that they say exactly what I've said about White Balance not being applied to raw sensor data, ever.


I've never suggested the WB channel multipliers saved as metadata are not useful. Where did you get that idea? I'm just saying that is exactly all the WB data is, a set of channel multiplier values, one each for Red and Blue and two for Green, that are later applied to an RGB image and are never ever applied to raw sensor data.
The above is output from exiftool. the top line shows raw values, the second line is normalized to set the Green channels to 1.

Those values are literally plugged into the source code for a RAW converter. These lines are code from UFRAW (written by Udi Fuchs, and are values that I provided).
Note that all of the presets are "well known", and RAW converters can actually ignore what the metadata tags are. With Canon the cameras Auto WB multipliers are always recorded in the metadata, even if Auto WB is not enabled. But Nikon only embeds the camera configured multipliers, so the camera's Auto WB values are not available unless Auto WB is enabled.

jcboy3

I recommend you review my previous posts.

I did not say that any of these file formats were "images", I was stating that they were all image file formats, and that images were derived from these formats (with varying degrees of effort). Not once did I discuss what constituted an "image".

I did not say that WB was applied to the image sensor data in the file, but that it was stored in the file for later use.

On the other hand, you did say that the WB data was non-essential. I allowed that this was your opinion, but I stated that, to me, it was essential.

Architect1776 Loc: In my mind

Gee I guess I am doing all this wrong by enjoying taking photos, worring about composition and other such mundane things like trying to capture the moment and the feeling. You guys have sure enlightened me on my failures as to what is really important.

jcboy3

I certainly hope that is not the case. It was not my intention to let this devolving discussion of image file formats have any impact on the more important elements of photography.

At some point in this discussion, the OP question was answered. The remainder, I think, can be summarized as a philosophical discussion of the nature of an image.

As such, I am unwatching this thread but will open a new one on the topic.

canon Lee

Phewwww. enough already!! It seems like you being a consultant, perhaps like" Jonathan Gruber" you feel you know more than the rest of us and think we are " STUPID". You just can't let it go. Being right means everything to you even in the face of you being wrong. You are not helping the new-bees with your intellectual ramblings, you in fact are confusing them. I do not think you are capable of "keeping things simple", because you can't resist the opportunity to show how much you think you know. BTW "professor" I don't know how my car is engineered but I certainly can drive it, without knowing all of the technologies that "engineers" know to design it. Leave answering the new-bees questions to us "stupid" ones, we know how to relate to the beginners, since we all were one at one time! If my reply to you seems harsh, It is, but I am sure you have had others do the same. Learn from us, and stop teaching us.

Architect1776 Loc: In my mind

Good response.
This is a good forum to do some debate but should be how to see better photographically with a few Nikon/Canon jabs.

redrocktom Loc: Sedona

I think we should welcome all input and opinions from all contributors. No one is forcing anyone to read any one reply. So I want to thank all of those with the knowledge and experience base for making things easier to understand for us less experienced. And I also want to thank the "techies" for their contributions. Sometimes I like to read and learn the tech detail. It's always my choice.