"The Portfolio:Pro Invitation" - Constructive Critiques / Discuss

koaflashboy    says:

My apologies for the duration between the first thread and now - as promised - Part Two. For this installment, we'll move forward with a raw workflow and take a look at Adobe's Camera Raw plugin that ships with Photoshop (beginning with CS). The version I'll be using is the beta version of the plugin from CS3. Some features (particularly Recovery and Fill Light) I have found to be fairly powerful, albeit yet very useful. Vibrance is a nice touch for adding saturation (supposedly) without affecting skintones and it does a fair job. The Parametric Curve and the HSL tab are also powerful additions, but for those not yet on CS3 or able to get their hands on the beta, I'll call out the differences between the new version and previous versions.

But that being said, assuming ACR (Adobe Camera Raw and how I'll refer to it from here on out) has been profiled for your particular camera (and you can find out if it has here) and you've amassed a few gigs of raw image captures, we can begin.

When you double-click a raw file to open in Photoshop, what you'll see is the raw plugin - not Photoshop. We have a little bit of work to do before we can open it into Photoshop proper. But this is the fun part, so here we go.

Here's what the main dialog looks like for an image we've just opened (my apologies for the 'postcard' quality of the image) -



What we see are some tools up top, some choices at the bottom, and then a mess at the right, including a histogram. Obviously, this is a rather poorly exposed image as we can see from the histogram (most information captured is darker than a midtone - not ideal by any means). But that aside, the interface is streamlined and we'll move through it in a straightforward setup because that's how it's been designed.

First thing is color space, depth, size and resolution. This is something I touched upon in that first thread (which, by the way, can be found here in case any of you didn't catch it) - the bit about color space. Here, we're able to specify which color space we want to open our image into once we convert from our linear capture to a nonlinear file. The list (on a Mac) includes AdobeRGB (medium-sized space that is a good choice and nicely grey-balanced), ProPhoto (a monstrous space developed by Kodak that encompasses all colors that our eyes can see), ColorMatch (an Apple color space that is fairly small), and sRGB2.1 (the Windows/web defacto space that, like ColorMatch, is quite small and should only be used for images destined only for the web). I've chosen ProPhoto of course and would recommend that for just about any image - we can always convert to a smaller space later on down the road but why toss color information straight away?

Next we'll choose our bit depth. This is of course (like much of digital imaging) up for debate, but I typically choose 8-bit because 16-bit files are huge and I don't often find a lot of use for the extra bit depth unless I've lost a lot of highlight detail, which - if I have - I tend to toss the image in the trash can rather than fuss with it. You'll also notice the ability we have in ACR to resample, both up and down. I've tested this out and have come to the conclusion that if you know your final size that you're intending, that it's a slight advantage to do it from the linear capture rather than the nonlinear file later on in Photoshop. Granted, marginally - but still a bit smoother with less noticeable artifacting. I'm able to resample up twice from my 4MB raw captures (Canon G2) and get perfectly acceptable 11x14" prints - even, in some cases, with additional resampling a not-too-shabby 16x20 (which is quite surprising and wouldn't be possible without having been able to resample the nonlinear capture).

The tools at the top are pretty self-explanatory, and the checkboxes for Shadows and Highlights simply mean ACR will show you which highlight or shadow pixels are blown out if you check them.

OK, moving right along then to the meat of ACR - the sliders at the left. They are laid out in such a fashion as to be processed in the order they are, from top to bottom. I always start with Temperature and set that first, then adjust the Hue (right shifts the color to the green spectrum while moving to the left shifts hue to the magenta end of the spectrum). Remember about perhaps forgetting to properly set your in-camera white balance? Not to worry! Maybe you're image opens up looking a little funky, but you can completely non-destructively change the white balance here with the flick of your mouse or pen. One thing to also keep in mind (as I've done on this image and you can see below) is the fact you can creatively set white balance judiciously. I've opted to set it a bit cooler than the actual temperature of the ambient light to give it a cooler tone. Play around and have fun - you're not hurting anything and you can always simply go back to your original settings.

(Speaking of that - the flyout menu at the righthand side of every tab houses some neat stuff that we'll look at once we've got our image the way we like it - keep reading).

Once those two are set, I'll next attack the Exposure. If you hold down Opt/Alt while sliding, you get a preview of what pixels are clipping. White pixels mean all three channels are blown - any other color means only one or two channels are blown. Remember, ACR will approximate blown detail even if all three channels are blown out in the original capture if you slide this far enough to the right and given the fact they're not horribly blown out by 3 or more stops.

The Recovery slider is new in CS3, and works in conjunction with the Exposure slider to eek out a bit more blown detail without affecting the rest of the tones. Similarly, Fill Light and Blacks (formerly Shadows in CS and CS2) work together to adjust the shadow densities of the image without affecting other areas. And, as with Exposure, holding down Opt/Alt on these two allows you to see which pixels are being blown out with the exception that black pixels mean all three channels are blown).

Working with the combination of these simply takes some practice but their power is very real and you'll get that after working with them a bit. It is in this tab (Basic in CS3 - was Adjust in previous versions)that I do most of my adjustments (as in, 90%). And once you're familiar with the sliders, you can do this very quickly - 30 seconds or so and you should be satisfied or it's time to toss the image and move on.

Here is what I was able to get to by adjusting these sliders for the above image -



Quite a difference!

So moving to the next tab - and be forewarned, the tabs have not only been increased from five to eight in CS3, but they've been rearranged. Normally, the Detail tab is next - but now we find the Tone Curve tab. Here, jumping out of order is less of an issue, so we can jump over the HSL/Greyscale and Split Toning tabs to the Detail tab. In this tab, we find sliders for Sharpening and Noise Reduction.

I've also tested sharpening in ACR vs. both the standard Unsharp mask and CS2's Smart Sharpen filter (I do do this for a living, in case any of you were wondering what sort of geeky life I lead) and I've found both tools in Photoshop to be more powerful than sharpening in ACR, so if I sharpen in raw I set it as a preference to only sharpen the preview and not my actual file (go to the flyout menu at the top right corner of each tab and you'll find Preferences... where you can select Apply Sharpening To: "all images" or "Preview Images Only").

But the noise reduction is really the huge thing here - another point I mentioned in Part One. Here you'll see the image as shot, even at ISO 50 but since 90% or so of the information was below a midtone so it's fairly noisy -



And here it is with Luminance Noise reduced 50%, sharpening boosted up (on the preview only) and Color Noise left at the default (I rarely find that Color Noise has much effect - certainly not as much as Luminance Noise) -



That's a pretty remarkable difference, and all this has been done to the raw capture before we've even converted! Powerful, powerful stuff.

The next tab to the right of Detail is Lens Corrections. Here again is a powerful set of sliders, namely the Chromatic Aberration ones. This feature can be found in Photoshop under Filter/Distort/Lens Correction - but beware it's much more crude in Photoshop proper than it is in ACR. To fully get the power out of these sliders, set the zoom factor to 1:1 (100%) and hold down the Opt/Alt key while sliding them to view a more distinct preview that allows you to really see any Red/Cyan or Blue/Yellow aberrations. If there are any, and aberrations can be typically found on high-contrast edges towards the sides of the frame - this is the place to remove them. I find an adjustment of between 20-30 is all it takes, typically to the Red side (move the R/C slider to the left) or the Blue side (move the B/Y slider to the left).

Here too, you can either correct lens vignetting or introduce it for an effect.

Now, let's jump back to the Tone Curve (or simply Curve in previous versions) tab. Also new in CS3 is an additional sub-tab called Parametric. Previously, we just had the tone curve which is not to be confused with Curves in Photoshop proper. Remember, we're dealing with a linear file at this point, so if you tweak this tone curve too much, you'll see some fairly nasty results.

So I've simply used the Strong Contrast default in the Point curve as seen here -



If for no other reason that adding custom points and shifting the 3/4-, mid-, and 1/4-tone points around did not yield a more desirable effect. But, it is really in the new Parametric sub-tab that we can fine-tune our adjustment to an alarming degree.

We have the option obviously to tweak Highlights, Lights, Darks and Shadows. The really powerful aspect of this curve is found in the triangles along the bottom of the curve diagram. Slide these around to adjust what tones are being affected by each slider. As can be seen here -



I've moved all three of them to bring in some extra contrast to the shadow tones without muddying up the dark rock at the righthand edge of the frame. The Shadows are only being adjusted to tones to the left of the leftmost triangle (I've set them down 45 points for increased contrast). I then boosted the Darks (where the tones of the dark rock mentioned above can be found) in the narrow band between the leftmost and the middle triangle. Lights then were really tones between the 3/4- and mid-tones (boosted only slightly by 5 points), while Highlights covered everything above a midtone (again, boosted only slightly 5 points). Remember this image's Histogram? Most tones were below the midtone, and based on what we remember of linear capture and 50% of the information being captured in the highlight stop - that is why I've set the Highlight triangle as I did, even though I didn't push it too far.

Very, very cool stuff.

OK - we're almost done. The next tab I would jump to is the Camera Calibration tab (simply Calibrate in previous versions). Typically, you actually don't want to mess with this because Thomas Knoll & Co. have gone to great lengths to profile your camera for you (that's what it means if ACR can interpret raw files from your particular camera model - that a profile for that specific camera has been created that tells ACR how to render the image by default among various other engineering feats). But if you see a pattern of your images opening and having, say, a green cast or the reds are overly-saturated, this would be the place to change that. And one slider in particular in this grouping I've found to be very useful is the Shadows Tint slider. I find a lot of times shadow tones have a bit of a magenta cast to them, and a simple nudge of this slider to the left takes care of that cast without affecting anything above the shadow densities. Very cool.

You're of course free to experiment with the Hue/Saturation sliders for the RGB channels respectively - but again, remember this is a linear file still so the tool does not have the same intuitiveness as the Hue/Saturation adjustment in Photoshop proper.

That, then, is what the Hue/Saturation/Luminance (HSL) tab is all about. Unfortunately, this is a CS3 exclusive so without either the beta or purchasing this, you're stuck with what I've told you and you can skip down to the end when I touch on the flyout menu options I mentioned at the start of this incredibly (I'm afraid to look) long thread. The HSL tab is a bit more intuitive, but still can cause disastrous effects if used too liberally.

All three tabs are fairly self-explanatory (and I'm not just saying that cos I've been typing this for almost two hours) - Hue adjusts the color of each of the selected colors, Saturation adds or removes saturation from each of those same colors while Luminance brightens or darkens each of the selected color ranges without affecting either of the other two properties. I've used it sparingly as shown below -



The greyscale functionality is of course new to CS3 as well and can be used like, albeit as all adjustments to a linear file not quite as intuitively, a channel mixer conversion in Photoshop with even a bit more fine-tuning because you can adjust eight channels to really hone-in on the conversion you're after.

One thing to keep in mind on all adjustments to the Curves or HSL tabs - smaller moves are better as large leaps of the sliders will typically give a pretty messed up looking image. But used sparingly, they are indeed immensely powerful tools.

OK, finally lets take a look at the flyout menu quickly before leaving this for Part Three, where we'll examine automation and batch processing to speed up our conversion from raw files to workable files we can further retouch and adjust in Photoshop while maintaining all the power and flexibility of a raw workflow.

Alright, the flyout menu then.



First, we see at the top various settings we can choose-

Image Settings are those that we have set by adjusting everything I've just talked about and after having saved our file either as a .dng (Digital Negative format) or back to the raw state with the XMP metadata that will tell ACR what settings we've chosen when we go to reopen this image (more on that in a second).
Camera Raw Defaults are the default settings ACR uses when it opens your image, based on your camera settings and the profile it has for your camera model
Previous Conversion - takes whatever settings you made on the last image you successfully converted by pressing either Save or Open.
Custom Settings are the settings you've chosen before you've saved your file.

You'll then see - if you look down a bit - the ability to both Load and Save Settings. By choosing Save Settings... we're able to save whatever combination of settings we choose as a preset, which will then give us the ability to Apply Preset as shown below the settings options I just talked about. We'll cover this in more detail in Part Three, but sufficed to say this is how we can begin to batch process and even automate our raw conversion.

You can save your current settings as New Camera Raw Defaults so that each subsequent image you open will do so with those particular settings. If you change your mind, simply select Reset Camera Raw Defaults back to the plugin's defaults.

Finally, we can look at Preferences -



Like I mentioned, you can choose how to apply sharpening, and also how to save your image settings to raw files. I choose to save them as .xmp sidecar files, meaning that with every image file you have you have a small, accompanying .xmp file that contains the XMP metadata tags ACR uses to know what settings you've chosen (if you're really bored or just truly a geek, you can open the .xmp sidecar in any text editor and have a walloping good time reading through it). Of course, some of you may cringe at the fact of an extra file with every image you convert, which is why ACR gives you the option to save them to a database. Beware of this, however - this means that, should you ever choose to move your image or, say, burn it to a CD or onto a flash drive for whatever reason, when you go to reopen it in ACR - the plugin won't have any idea what settings you've applied unless you've gone in and remembered to grab the .xmp file for the particular image file(s) you've moved.

The checkboxes for Default Image Settings are pretty self-explanatory - but we had a member asking about the auto tone adjustments in the first thread because she didn't like the fact ACR was applying auto tone adjustments to her images. If that's the case with you, simply deselect this as I've done. I've chosen to have ACR make defaults specific for my camera serial number and ISO setting but that's it.

I've never bothered messing with the cache size or location - feel free to do so if you are so inclined. Not a bad idea to periodically purge the cache if you can remember to do so.

And finally, DNG file handling is also self-explanatory. We'll talk about a DNG workflow more in Part Three so I'm going to leave this for now.

And there you have it. More or less a walk-through of Adobe's pretty fantastic camera raw converter. Post any thoughts or questions of course - even just a note saying you read this and found it helpful would be good for me to know the last three hours I spent of my life putting this together were worthwhile to someone.

Oh yeah - and don't forget to take a look at the final image here -



and compare it with the default raw image at the top of this thread - there's not a whole lot of further editing that we need to do in Photoshop at this point. Of course I'd apply the color correction magic I talked about in this thread, and perhaps add a luminosity curve to boost contrast, maybe boost some saturation in particular colors slightly, but that's about it.

And remember, this was all done non-destructively before we even converted the file. If we want, we could go back to this raw file and try a hundred other manipulations without ever losing a single pixel that our camera captured. Like I've said - pretty cool stuff.

And, as always, happy shooting!

cheers

Finally - here's a link to the list of all TECH THREADs posted to date.


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Originally posted at 11:39PM, 1 May 2007 PDT ( permalink )
koaflashboy edited this topic 23 months ago.