Getting it right in camera II - Image formats:
A lot gets written about on the topic of image file formats especially such as jpg, raw and tiff.
Each file format has it's advantages and disadvantages. Most of us generally know and understand these nuances, and for total newbies to digital camera/image file formats, there is much more detailed info available on many other sites than I can describe here.
One thing to note here .. I'm no expert on the topic, and I can only reiterate accurate info on the topics as I've come across the info myself.
I don't pretend to know every bit and byte of data on the topic of image formats, but having had some unique experiences, I've collected a fair amount of info and like to share it with those that care to know.
While some of this thread will involve an opinion(in my situation .. my opinion) .. I'll try to keep the majority of the info on a factual basis.
On the other thread that resulted in this discussion/thread, much was made of file formats and what they are and how they're represented .. and some of it was written as an opinion, not fact.
While these opinions can be true for some, they're not true for everyone concerned with the topic.
Hopefully my thread will explain the differences.
Because this thread is as a result of the slightly OT discussion on the other getting it right in camera thread, I'll start with some aspects of geting it right in camera file formats.
JPEG: there is nothing wrong with using this file format to get images out of your camera. If you get them right every time, kudos to you and happy shooting.
But if you can't accept the point that no matter what you know, there is always something else to learn .. then why limit yourself to a restrictive format.
As a matter of opinion, I (along with many other people) believe that the JPG format is not the best file type to be shooting in camera. As already said, there is nothing wrong with it per se, but it is more limited in at least two ways.
1/. it's a limited, compressed and completely cooked data file.
(FWIW: jpg is not an image exactly! .. it's a set of data that isn't all that much different to how raw files are rendered .. more on this later)
2/. because it's a cooked file format, it isn't the best file type to use for learning(again more on this later.
We already know most of the limitations of the jp format .. ie. 8bit colour, compressed data(even at 100% quality .. it's still compressed .. etc).
While 2/. is as much an opinion on my part as the opposite view is from other's, part of my opinion is based on fact. The facts are right .. but if yours is an alternate opinion on this subject and hence in opposition to mine, then you will see my opinion as wrong!
All the best to your POV, but if you want to express your opinion on the topic as definitive and right .. then at least some facts should be presented as to why.
Here's why I think my opinion is the more relevant.
The better file format to shoot in camera is raw. Always! Once you have an image shot in jpg, you can't instruct the image later on in Post Processing(PP) to render in an opposing manner with respect to colour.
And by this colour, I mean whitebalance(WB).
if you accidentally shot a jpg image at WB setting of 2500K .. good luck to you trying to get it to an accurate WB setting of 10000K! You won't.
The attempt to do so will only result in posterization, as you will be pushing this limited compressed and lost data to an extreme it was never meant to achieve.
(while this an assessment of mine and hence my opinion, it is also based on some facts. Both technical and personal experience on a few image editing programs .. but those programs exclude Photoshop!)
Whilst WB is one of my main reasons for using raw, there are also other important reasons to do so.
In camera picture style rendering.(Nikon calls them Picture Controls .. other manufacturers call them other things .. I'm a Nikon user, so I'll stick with pc's .. which is not personal computer!!)
In the other thread linked too, a comment was made that the in camera picture styles(pc's) are not rendered in the raw file. That is(I think) that the pcs don't actually render the raw file.
While this is partly correct, in reality nothing renders the raw file unless you have a raw converter to do so. Some raw converters do render the file as per the pc's, some don't.
In effect, this is your option. You can choose if you want the pc's to render correctly or not in your workflow. Like I said tho, while it's partially correct, on the whole it's wrong! very wrong.
What the original author of that statement said is not a fact, it's an opinion. While it's right for them, it doesn't mean that it's right. If a piece of info is to looked upon as right or wrong, it has to be for everyone .. not just the person making the claim.
So as already said, while my view on the subject is an opinion(which makes it right for me), it's also based on a small fact.
So if you just got lost in that small diatribe:
the picture style(pc's) used in camera(most cameras nowadays) is a set of instruction to render a raw file in a particular way. That set of instructions causes the raw file to have a specific look. This look is then cooked into the raw file. You way choose to see it, or not .. but the fact is that this cooked look to the raw file is there .. always! There is basically nothing you can do about it other than deconstruct the raw file .. which may render it to be useless!
What is an image file:
Firstly, a jpg file, what is it? It's a collection of dots(pixels) that will display on your computer screen. Some folks think that jpg images are set one way and thats it!
Nowadays this is almost certainly right, but not strictly speaking.
A jpg is not a series of pixels that gets displayed onto your screen.
it's a set of instructions of a set of data that the computer renders onto your screen.
Nowadays the point is moot, but not all that many years ago, it may have been. It's doubtful that any issues of the format will arise again as the patents issues have been dealt with. Years ago there was an issue with the patent and as I remember, some software developers created their own codecs to render the jpg files in their software. For some reason Irfanview comes to mind on this.
The key word there tho was CODEC.
What the jpg file format isn't, is a set and forget and render the same way every time file format.
The file's rendering is open to interpretation by the codec used by your OS, or software.
Why is this useless piece of info important?
Really, it's not, as it seems that all vendors use the same basic codec, but it also appears that this wasn't always the case.
uses a different jpg codec in their system to the one Apples chooses to use.
Even tho M$ and Apple choose to use their versions of the jpg codec for their system wide applications, there is no reason to believe that Adobe, Nikon, Canon, Pentax, Phase One .. all use those same codecs in their software as well! they may well use their own, or an open and freely available codec.
This is important to understand because, in effect, it's basically the same way raw files are 'seen'.
Once again, because I know zero about other raw formats, and something of Nikon's NEF format, I'll try to describe what I know of it. While it's not a lot, it's enough to let you all in on some secrets about it.
An NEF is a collection of pixel data, that gets contained in a file format, that needs to be(on the whole) rendered via a raw converter. The raw converter is basically using it's codecs to reassemble the data into a viewable image. ie. basically it's the same image rendering description as the jpg file.
While raw files are on the main, tiff files, they are also jpg files.
Yep! you read that right.. a raw file is also a jpg file.
But not directly. This is the secret tip part I was referring too earlier.
Inside the raw file container, there are not only millions of pixels data points to interpolate, and instructions on the side to interpolate them in a specific way, but also some jpg files. For NEF, that will be three of them. One is very small 300x200 IIRC, the other is a medium size(about 1000pixels or so, and the other is full size(the size of your sensor pixel dimensions).
NOT OPINION, BUT BASED ON SOME LOOSE INFO!:
My understanding of the middle sized jpg is that it's dependent on your review screens pixel dimensions, but I'm not entirely sure? Any factual info with respect to this is welcomed.
But the point I'm trying to make is that while other's believe that raw files are not totally cooked, and as a generalisation this can be correct. The reality is that even raw files can be partly cooked.
So what this means is that a raw file set with specific pc's CAN and WILL(if the conditions are right) to display in a certain way(or rendering).
You can, or may, see this in almost any raw converter, depending on how your raw converter is set up.
I've seen this in many raw converter programs. RawTherapee, Lr, CaptureOne, Nikon's converters, and other software I can't remember .. actually .. my fave viewer .. FastStone's FSViewer! .. etc.
So what does it mean that your raw file is also a jpg file?
That is, how can it make a difference?
because there is a jpg file(actually 3!) you can extract those files(maybe not all, buit at least some) using very simple software, which ARE NOT raw converters.
The one I tend to use more is IJFR .... InstantJpegFromRaw, is what the acronym stands for, which explains waht this program does. it extracts the jpg from the raw file. What it doesn't do is convert the raw file into a jpg file, which is what a raw converter does.
Again, as for jpg files, the important operative word used earlier is codec.
All raw converters need to use a codec to render the image file.
Some manufacturers don't share the inner workings of their raw files, and so other software vendors need to create their own.
This is where the confusing situation of raw file rendering is created.
Nikon's raw converters all render the raw file exactly as per the settings on the camera. pc's in this instance come into play. The pc's you set in camera, using the manufacturers software will almost certainly render the raw file as per the cameras pc settings.
The comment made that picture controls set in raw files aren't rendered in the raw file is not correct on at least two fronts here.
1/. the jpg files inside the raw file are set in stone(in a manner of speaking) they are cooked to the required process recipe set by the camera. No ifs or buts.
2/. Using a specific raw converter, you will see the raw file as it was set by the cameras pc's .. again no ifs or buts.
-Nikon software will only ever render the raw file as per the pc's chosen in camera .. again no ifs or buts. You don't have an option in the process.
On the face of it this may sound a bit limiting, but the reality is that it's a bit of a blessing.
(your manufacturers software probably works the same way)
What this means is, that if you choose to use your manufacturers software, you can alternate through various pc's to see which one renders better, or nicely, or appropriately.
What this situation then does for us, is take us back to the beginning and makes it easier to teach us what camera settings allow us to create images that are right straight out of camera.
The alternative is if you choose to use jpg in camera, to achieve the same level of what can be a complex learning curve, you could shoot thousands of images in jpg mode, with in camera pc's cooking those jpgs, and review them all on the computer to see which one you prefer!
if you're a glutton for punishment .. then use jpg mode thousands of times ... and that's your choice.
But for the rest of us that may like to set up our images in multiple and/or various ways, sitting in front of the computer, alternating through various pc's cooking processes is a lot easier to learn about what camera pc's settings do for for the look of the images.
This part of the image editing workflow is optional .. and not forced upon you.
Once you have them the way you like, you can then upload the the pc's to the camera(most cameras have the option to upload YOUR pc's settings .. then shoot in jpg knowing you have got the shot right in the camera.
But again, why limit yourself to such a narrow perspective?
Keep shooting raw mode, as you already have a jpg in the raw file! .. extract that jpg(as you now have a jpg straight out of the camera anyhow!!) but you then have the option later on in life if you want to alter the raw file to something else.
OPINION (... kind'a ... more of an observation really)
One thing Nikon have taught me is that, over time, they 'improve' the Picture Control editing options in their cameras and software.
Again, at the least, this comment is Nikon specific .. your camera manufacturer's workings may be different.
OPINION (... I think)
I'll go back to the "raw is a jpg" comment I've made, and how it can affect non manufacturer's raw converters.
What I've noticed as I've been trialling other raw converter software(of which include many brands), is that on initial loading of the raw files into the converter itself, the thumbnail images presented in the software will almost certainly be those of the embedded jpg preview files in the raw file.
This doesn't mean that ALL raw converters will do this .. just the one's I've tried(and have).
LR4 and 5 do this, Capture One also does. Most image viewers also do this too.
When raw files are viewed in most software, there may/will be a setting which allows the software to view the embedded jpg file(s) in the raw file.
With some software you can enable/disable this setting.
With Windows, I've never seen the option, and have only ever seen it render the embedded jpg preview file(s).
Small jpg for thumbnails, and if you want to view the larger full pixel version, it must then use the full sized preview file.(I don't think these software use the mid sized file .. this may only be a Nikon setting for viewing on the camera's review screen.
A note for some native OS environments: For Windows to see the raw file, the codec from the manufacturer must be installed. This could be native to Windows, depending on the version, in some instances where the OS is older than the camera model, you download and use the manufacturer's latest codecs.
Either way, whether jpg or raw .. a codec must be installed on your PC to view the image.
With jpg this is simple, your OS(or software will have one by default).
Just because you can't see this or don't know this, doesn't make it an opinion.
It's a fact. jpgs are not some miracle file that is ubiquitous and that all software can see or use.
ie. you don't just see them, they get rendered.
I've noted a slight difference between jpg rendering on a few occasions myself.
A long time back(maybe 5-6 years ago), I had an instance where a jpg file was displayed one way in one software(Lr4) but totally different by other software(Nikon's CNX2 and VNX2).
I have no idea why other than the only way to show this problem was via screen captures.
I never got to the bottom of the issue other than I haven't seen it ever again.
My OPINION is that some software may use different jpg codecs to render the images.
If anyone has any information contrary to my findings or facts, I'm happy for them to share these findings.
Opinions are OK, facts are better .. but opinions presented as facts are not cool. It doesn't help anyone interested in the topic to learn about it.
Ken Rockwell wannabees be warned!
In a later post, I'll show some examples of in camera raw files that have a unique look to them, and I'll also post some info on how to use Picture Controls to an advantage.