2:52 pmOff
Camera Raw Workflow Options
You know that "link" at the bottom of Camera Raw?

Camera Raw Workflow Options "link"
It allows you to change a couple of important Camera Raw options. These settings are not image-specific, meaning that they are not saved in the metadata of a file (be it in the XMP or embedded in a DNG) and therefore cannot be synchronized between images. These settings are global and if you never change them, they will never change from image to image.
With that said, let's look at these options in more detail:

Camera Raw Workflow Options Window
First of all, we have to understand that a raw file is not yet processed, it is not yet a matrix of "pixels", therefore it doesn't yet have a color depth or color space — it is only the end result of the processing that is made to fit inside those constraints.
In order for Camera Raw to present to you a preview of the file as it will look like once processed and to present to you an histogram that is representative of that preview, it has to know to which color space and bit depth you will export the file. (If you've been working with Adobe Lightroom, you know that there is no such option window — that is because Lightroom works natively in ProPhoto RGB at 16 bits/channel and only (optionally) converts to more restrictive constraints when images are exported or sent to an external editor.)
In Camera Raw, you will notice right away that if you choose a smaller color space in the workflow options (say, sRGB), the image preview and histogram will automatically reflect that change: highlights and shadows will be clipped far sooner, as a result of values being constrained to a narrower gamut. Therefore, you should set these options before you start processing your raw file, otherwise you will be mistaken in setting your white point, saturation and other significant values.
Speaking of color spaces...
Different people have different opinions on the matter of color space, but I prefer to work just like Lightroom, in ProPhoto RGB at 16 bits/channel, and only squish image data at the very end of the workflow (usually when exporting images for the web). If you've been reading reviews of the latest inkjet printers, you will know that Adobe RGB is not big enough any longer. Here is an excerpt from a review of the Epson Stylus Pro 7900/9900 printers:
This new ink set is called Ultrachrome HDR and for the first time in an Epson Pro series printer Green and Orange inks are utilized. This actually allows these printers to exceed Adobe RGB in certain parts of the spectrum, by a not inconsiderable margin.
What this tells us is that we don't know what new technology will pop up around the next corner, therefore we should keep as much information in our original files as possible — it doesn't hurt since we're keeping the files in 16 bits/channel.
Speaking of bit depth...
Indeed, there is no question that you should work in 16 bits/channel. 8 bits/channel is generally okay for a final image, but not for one that is still subject to manipulation (since, as we know, manipulation implies loss of information). If you start with 8 bits/channel and manipulate, you will end up with less than 8 bits/channel, and this will likely show up as posterization (especially in smooth gradients) — you know you're in this situation when your histogram has gaps.
That being said, Color Space and Bit Depth are really the only two workflow options you should consider while working in Camera Raw, as they are the only ones that will have an immediate effect — all the others will only have meaning once you export the image out of Camera Raw.
The only time you would play with the other settings (Size, Resolution and Sharpening) is if you were going to use Camera Raw itself to export finished products. I personally prefer to let Photoshop handle that, so I actually never touch these settings (except the first time I open up Camera Raw after installing the Adobe Suite, of course), leaving them as they appear in the screenshot above, for optimal quality.
The problem is that if you change these settings, the next time you open up Camera Raw, you will have to reset them back to the original values — something you are likely to forget, which would mess up your files (more on that later). This constant hassle to reset the settings back and forth depending on the usage of the file (immediate export vs. further work in Photoshop) is enough to make me want to batch process my exports through Photoshop and always leave these options alone to the optimal quality.
To complete our exploration of the options...
As I was saying, unless you're going to, say, export JPEGs for the web directly from Camera Raw, you should leave the Size option to the 1:1 value (no upresing nor downresing). Resizing is better left to the specialists — the algorithm applied here is not as optimal, nor as parametrable as the one you can use in Photoshop. Every resizing calls for interpolation, which means loss of detail, so you should only go through one resizing procedure, if needed, at the very end of the workflow, before you export.
Resolution, as it's been said before, doesn't mean anything until you start talking about printing. Whatever value you put here is meaningless as long as the file is not actualized. Stick to 72 if the file is going on the web (merely because that is the established standard), but otherwise, this number has no effect on the image whatsoever.
Output Sharpening, too, should definitely only be used if you're going to export files directly from Camera Raw. This, too, is a step that should be done at the very end, and is specific to where the file will be going. You don't apply the same sharpening on files viewed on screen vs. files printed on glossy paper vs. files printed on matte paper vs. etc., so you shouldn't apply it at this point if the file will be going to Photoshop for further processing.
To wrap up
Frankly, unless you're going to use Camera Raw to export images directly, to get optimal results, save time and avoid mistakes, I strongly recommend you use the settings shown in the screenshot above and never bother touching them again.
But it gets better...
Wouldn't it be nice if you could just change your mind later, once you're in Photoshop and it's too late because you've left Camera Raw? Wouldn't it be great if every setting in Camera Raw could still be changed later, once you're in Photoshop (and I really mean every setting, not just the workflow options)?
Well, they can, and it's amazingly simple to do! Instead of using the "Open Image" button (which rasterizes the raw file for good), simply hold the "shift" key to turn the button in an "Open Object" button. Ta-dah! You're now working with a "Smart Object": the raw file is now embedded inside your Photoshop layer and can always be edited back in Camera Raw when needed.

Raw file appears as a Smart Object
To bring the raw file back in Camera Raw, simply double-click on its thumbnail, and voila!
Note that this embedded raw file is not linked in any way to the original raw file that was opened as a Smart Object — you could always move the initial raw file or delete it altogether and it would not affect your image in Photoshop. Note as well that any Camera Raw parameters you change when editing your Smart Object will not be applied to the original raw file neither. It really is a copy of the raw file that was embedded inside the Smart Object, not just a link that was established.
7:18 pmOff
Expose to the Right (and then some)
Following up on the previous post, where I was making the point that fully embracing the new photographic technologies meant more than shooting raw, I would like to point out to a recent post by Michael Reichmann. His text, from just a couple of weeks ago, was an open letter to Leica, explaining his ideas on how to improve their cameras.
The most interesting part of the letter, for me, wasn't so much Leica-related, but the part where he clearly stated how camera makers (and camera users, by extension) should fully come to terms with the actual behavior of the current technology:
All major digital camera makers seem to be stuck in the film era when it comes to exposure metering and setting. Part of the problem is that consumers want the image on the rear LCD or in the viewfinder to "look right", but looking right and being optimum from a raw image quality perspective are not the same thing. [...] In other words – let's leave the film exposure paradigm behind. Digital exposure is different than film exposure, and basing 21st Century cameras on 19th Century exposure rules has to end.
Well that's all good — we're all familiar with the "expose to the right" approach to optimizing exposure, and that understanding leads us to deliberately use generous exposures in the field, when gathering ambient light.
But what about when we're working in a controlled environment, when using strobes in a studio for example? There, it's as if we suddenly forget the "expose to the right" mantra and rather rely on our flash meters to calculate the exposure. If we want to push the reasoning all the way, shouldn't we reconsider our approach?
Let's consider this very simple experiment. Single Speedlight in a Lastolite EzyBox to camera left, ISO100 at f/5.6. This is what we get (as expected): a "correct" exposure.

Flash Meter at f/5.6, ISO100
I took an item on my desk that contained bright white, so that we can really see what's going on:

Tissue Box at f/5.6, ISO100
Whites are white — no doubt about it. Now let's double the flash power (f/8), but leave the aperture at f/5.6. This is what we get, straight out of the camera:

Tissue Box, 1-Stop Over-Exposure
Overexposed! But of course, this is exactly what we would expect — exposing to the right is supposed to optimize the file, not get the best result straight out of the camera (or on the LCD display, or on the histogram). As a matter of fact, this is what the two histograms look like, without any adjustment:

Histogram Comparison
According to this histogram, we were too enthusiastic and went too far to the right — we know that we shouldn't clip the highlights, because then we can't bring them back at all. To adjust the exposure so that we get (visually) the same result as the first file, I simply pull back the "Exposure" slider in Camera Raw — I'm not even messing around with the "Recovery" hack, there is no need, there is plenty of information in the highlights. Ta-dah! This is the result I get:

Tissue Box, Exposure Adjusted in Camera Raw
Well well. Nothing is clipped now, I get information everywhere from that same file, which was over-exposed by a full stop.
The question is, did this really have any effect on the quality of the image? Well yes it did indeed. Remember that this image was shot at ISO100, so the noise was already pretty low. But by taking a region from the blurred background and bringing up the exposure to get a middle gray (which, obviously, enhances the noise further) and removing any kind of noise reduction there was, we get this result:

Noise Comparison (200%)
I will grant you that, in practice, this would not be much to write home about. But certainly, even in an ideal situation, there is a difference — deeper shadows, in particular, would benefit even more from this 1-stop gain.
Now this is where it gets interesting. Because we know that the "expose to the right" approach has a more obvious impact on the quality of a file in the shadows, and especially when we're dealing with high ISOs, there is another situation where we should definitely apply it.
When we're working in a mixed "flash+ambient light" exposure! In these situations, we normally have large parts of the image in darker tones, and we're usually working with rather high ISOs to get acceptable shutter speeds. The typical exposure is usually somewhere around the -2 stops for the ambient, over which we add the flash. Well, I'll let you work out how you incorporate the lesson from situation to situation, but in the end it should probably look more like -1 stop for the ambient, +1 stop for the flash!
1:24 amOff
Camera Raw is not Just an Import Plug-in (Anymore)
Back in 2002, when Adobe Photoshop 7 came out, it featured a new plug-in called Camera Raw 1.0, to provide support for reading raw files. At the time, the functionalities offered by Camera Raw were very limited, and it was used basically as a mere import plug-in for raw files. Camera Raw started to be a more serious tool at around version 3 (with CS2), and by version 4 (with CS3) it had matured into a pretty powerful raw processor.
If you've been shooting for a long time and actually went through the transition from film to digital (I have not), you've had to relearn your post-processing workflow many times over to adapt to the rapidly changing technology. You've likely started to work with digital long before digital cameras (and raw files) even existed, and your basic workflow meant scanning negatives/slides into high resolution TIFF files and going straight to Photoshop to do all the processing. When serious digital cameras came out and you started using them, you've been told that raw files contained much more information than JPEGs (or even TIFFs, for some cameras used to optionally shoot straight to TIFF), so you've gladly begun shooting raw.
Now even you are advocating shooting raw to preserve all the information the camera can capture — which is good — but you may still see the raw processing step as a mere intermediary to Photoshop, where all the serious stuff goes down. You'll say things like "Well, you see, here you have all these sliders that you can play around with to change your exposure, white balance, curves and all — kind of a simplified version of the basic functionalities you get in Photoshop... But, you know, we are all eager to bring that file into Photoshop, a much more powerful tool anyway, so we'll go right ahead and press 'Open'." You'll then lecture on using the Threshold adjustment layer to find your black and white points, using Color Samplers to locate them, and use a Levels or Curves adjustment layer to set the clipping with the black and white eyedroppers — you won't fail to mention that one should probably aim for 10 black and 245 white at most, because printers cannot manage further extremes; you'll add a Color Correction adjustment layer to fix the color cast; etc.
Now that's what is known as old think.
Don't get me wrong; I'm not saying this won't allow you to achieve satisfactory results — go right ahead and use whatever you are more comfortable with. Daniel Malka said it best when he said: "If it looks good, it's good, right?" If you've been looking at Joey L's early work, for example, and have been blown away by the results he achieved, you wouldn't really care to know that his Photoshop techniques were, at the time, profoundly lacking (as even he acknowledges).
But still, if that is the way you see your typical workflow, you are missing out on what raw files have to offer; you haven't fully embraced the digital workflow to the fullest; you have kind of a half-assed approach to image processing that is tainted by your past experience; you aren't extracting all the detail you can out of your files. Even a 16-bit, ProPhoto RGB TIFF file only has a fraction of what the raw file has to offer, for the simple reason that as soon as you leave the raw file, you are working with a baked file: everything you'll do to the image from this point will be destructive, and you'll never be able to extract all the detail that was available in the source file. That's because a raw file has not been demosaiced, it's still in a linear gamma, and all the settings you play with are only parametric: they are not affecting "pixels" yet.
For optimal results, ideally, you should be doing as much of the work as possible on the raw file (be it using Camera Raw, Lightroom or any other raw processor) and only open the image in Photoshop once you've exhausted all the possibilities, for more complex local/pixel-level editing (when needed). Camera Raw and other raw processors now even provide some level of parametric local adjustments (especially since Camera Raw 5, Lightroom 2, etc.), so there is no excuse. The white and black points (referred to as "Exposure" and "Blacks" in Camera Raw/Lightroom) are particularly important, because you cannot recover blown highlights once the image has been baked, no matter the bit depth and color space...
But don't take my word for it. For an excellent primer on the raw processing workflow, you should definitely read the first three chapters of the Real World Camera Raw books by Bruce Fraser and Jeff Schewe — even if you're not working specifically with Camera Raw. (Note that Lighroom uses exactly the same processing engine as Camera Raw.) Or you can always watch one of the comprehensive video tutorials with Jeff Schewe and Michael Reichmann back at the Luminous Landscape.
1:28 amOff
Exporting JPEGs for the Web from Lightroom
There seems to be quite a bit of confusion regarding the exportation of JPEG files from Lightroom. The "Export" window itself is rather straightforward, but you still have to know which setting is more appropriate for your needs. In particular, three settings may need further explanation.
Screen Sharpening
In a complete image processing workflow, there are commonly three different kinds of sharpening applied at different stages and for very different purposes.
It is important to understand that most of the sharpening is necessary even if one does not want to apply it "for effect", because of various limitations along the workflow. It should be noted that a basic sharpening workflow is not aimed at correcting soft images (caused by focusing error or motion blur), but at maintaining optimal detail in files that already contain as much as they can.
- Capture Sharpening (or Input Sharpening) is applied first and is necessary to restore loss of detail inherent in digital capture. That is particularly obvious when anti-aliasing filters are placed in front of image sensors to reduce moiré, as is very often the case (except on most digital backs, the Leica M9, and others). That is why the default behavior in Lightroom/Camera Raw and other raw processors is to systematically apply at least a basic amount of capture sharpening, which must then be refined manually (depending on various factors such as frequency). Note that this is true only when shooting raw files—shooting JPEGs means that the camera has already applied sharpening, so additional work on the file must be done carefully.
- Creative Sharpening is usually applied locally on specific regions of an image that require it most (such as the eyes and mouth when working on a portrait). This is the only kind of sharpening that is applied "for effect", where the photographer decides whether he wants his image to look natural or more crunchy.
- Output Sharpening is applied at the very end and is totally dependent upon the destination of the image. Luckily for us (and thanks to the work of Bruce Fraser and the guys at PixelGenius), Lightroom makes it incredibly easy to properly perform this task, which used to require a lot of trial and error. The thing is that if the image is going to an inkjet printer on glossy paper, the sharpening applied is not the same as the one applied for matte paper, and is not the same depending on the resolution of the print, and is very different from the one applied for viewing an image on screen. On one hand, inkjet printers inherently introduce a certain loss of detail because of the nature of the technology itself, so some additional sharpening must be applied—sharpening that would definitely look ugly if the image were to be viewed on screen. On the other hand, images need to be resized to be of an appropriate size for viewing on screen, and resizing an image calls for interpolation algorithms, which also means a loss of per pixel detail. This is why Screen Sharpening is required, not "for effect", but to maintain optimal detail when the image is to be viewed on screen.
Applying a "Standard" amount of screen sharpening to JPEG files exported for viewing on a web page is a very good idea—not to make the images look crunchy, but to retain an optimal level of perceptible detail.
Note that whether you intend to export images for the web or to print them, output sharpening is not something Photoshop will do automatically or even offer. When you want to do it yourself in Photoshop, the burden is on you to apply the optimal sharpening for a given destination—good luck! Do yourself a favor and just don't do it that way... Either print/export from Lightroom, or use PixelGenius' PhotoKit Sharpener and skip output sharpening altogether in Lightroom.
Resolution
When exporting images for viewing on screen, the resolution of the file has absolutely no meaning, so whatever value you put in that field has no importance and, contrary to what you might have been told, will have no effect on the exported file—files won't have more or less detail, and file size will not be affected at all. The important factor when exporting files for the web is the size (in pixels), not the "resolution".
Traditionally, images consumed on a computer screen have been set at 72 ppi (so you might as well put that), but that really depends on the resolution of each monitor—something you have no control over when you publish images on the web.
Color Space
If a file is going on a web page, because we cannot know if the browser used to view the image will support color management, we should aim for the common denominator (it won't support it) and choose the sRGB color space (the default presumption when color management is not supported).
The gamut of the sRGB color space is smaller than the gamut of the AdobeRGB (1998) color space, which itself is smaller than the gamut of the ProPhoto RGB color space—that much is true. But "color spaces" must not be confused with "color models".
The fact that most commercial printers offer very limited gamuts has nothing to do with the fact that they work in CMYK (a color model, not a color space). One simply has to have a look at Bill Atkinson's book to realize that commercial printers are technically able to achieve excellent gamuts and color fidelity when they put in the required effort.
In other words, the CMYK color model itself does not define the gamut, so it would simply make no sense to state that "CMYK has a smaller gamut than color space X".
2:12 amOff
Small test prints
So you want to do a test print on a sheet, but you don't want/need to print a whole-page test.
Yes, you may resize and drag around the preview image in the "Print" dialog box from Photoshop, but it's really approximate—chances are you won't fully exploit the real estate. Yes, you may use the "Print" module from Lightroom, with a certain cell configuration, and fill in the blanks with a bunch of dummy blank images until your test image falls in the right spot, but it's kind of a hack—why won't the software allow to leave spots blank and drag a picture around on the layout is a mystery.
Here's a different approach. What I do is I create a new document in Photoshop, the size of the printable area of the test paper, at a good resolution (say, 300 ppi), and I split the page using guides according to how big I want the tests. I only need to do this once, because I save the file each time I'm done with a test. The advantage is that I know exactly where the next available slot for a test print is on the test paper, and because I have precise guides to help me, I can fully exploit the available space in each cell.

Test print layout.
Before printing, all I need to do is hide the layers of the previous test images, so that only the last one is printed. When the document is full, I delete the layers and change my test page.
Don't forget to write a little marker on the back of the test page, so you always feed it in the printer the same way!