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Wednesday, November 08, 2006

Review: 'Real World Image Sharpening with Adobe Photoshop CS2'

by Joe Reifer

Secret Unsharp Mask settings, LAB conversions, layer masks: there has always been a lot of voodoo around sharpening images in Photoshop. Bruce Fraser, author of previous Real World series books on Photoshop, Camera RAW, and Color Management, has a relatively recent book called Real World Image Sharpening with Adobe Photoshop CS2. The book is divided into six chapters as follows:

A short introductory chapter explains how sharpening works by emphasizing edge contrast. In Chapter Two Fraser considers the difference between sharpening film and digital images, and balancing noise reduction needs with sharpening. Next we move into a superb explanation of varying your sharpening technique based on image content. Bruce talks about how a low frequency image like a portrait, which has large continuous areas of tone and gradual transitions, may need a different sharpening technique than a high frequency image like a city skyline shot with lots of tight transitions in a small area.

The theoretical foundations in the first three chapters build an excellent case for a two-step sharpening workflow, which considers the image source and content first, and then output usage. While sharpening your images twice may seem almost heretical at first, after reading the book I felt that my previous workflow of globally sharpening the image for output was rather primitive.

Chapter Four goes over how the sharpening tools in Photoshop work, including a detailed look at Smart Sharpen settings. That's all fine and dandy you say, but show me the money—how does Bruce do it? The various sharpening techniques are based on using Calculations to create a new channel, Find Edges to create a mask, adding an appropriate amount of blur to the mask based on image content, and then sharpening the edges through a mask. There are some great settings for limiting your sharpening to the midtone tonal range using the Layer Blend sliders. The steps are explained quite well, and if you follow along at the computer you'll easily be able to create a Photoshop Action.

Many of you are probably using third party tools for noise reduction such as Noise Ninja or Neat Image. Bruce includes a discussion of the Photoshop Reduce Noise tool, and some very simple and quite useful techniques for reducing luminance noise by using the Despeckle command on individual channels.

In Chapter Five the techniques are put together into a workflow. Whether you are a Photoshop novice or an experienced veteran, you're going to learn something useful here. Unsharp Mask radius setting voodoo is divulged. Low, medium, and high frequency images are analyzed in detail. Selective sharpening and smoothing are covered. Chapter six shows additional sharpening case studies on a 4x5 chrome, 35mm color negative, hard-copy scan, and both JPEG and RAW captures from a digital SLR.

If you want to just push a button and get great results, try out the Photoshop plugin from Bruce's company Pixel Genius called Photokit Sharpener. It's $100, and works great. If you want to understand how Photokit Sharpener works, or want to tinker on your own with sharpening, then Real World Image Sharpening with Adobe Photoshop CS2 is definitely worth reading.

Posted by JOE REIFER



Featured Comment by Richard Sintchak: I learned how to sharpen and prep my images for print and/or web presentation by reading the hints in Fraser's earlier book, Real World Photoshop 6.0, and by attending a couple all-day seminars taught by Fraser, Andrew Rodney and Jeff Schewe. So, I kind of learned the techniques from the grass-roots, basic level—all before Pixel Genius came out. When it did come out I considered it but found much more control in knowing the foundational elements used in PS to accomplish what PG pretty much did using canned Actions with slight tweaking. Also, even then Fraser had short, concise online articles that could be easily understood and followed in short order.
Actually I not only found more control doing it myself but found it so simple—pretty much a 3–4 step process—that I wondered why people would spend that kind of money for PG when they could do it themselves if they took only an hour or so of reading articles and then practicing (which never made anyone worse). Going the automated route might be considered easier, and things can seem to get complicated learning it yourself, but because images, their characteristics, and the output desired can vary so much, a photographer wanting the utmost in perfection would at least want to understand the fundamentals better so as to tweak them for their needs and understand why they are doing so, and what it is actually affecting.

I hope I'm not sounding haughty but I think taking easy shortcuts (and spending the money), on such things as Pixel Genius and saying that it's "good enough" can short-circuit your potential, much in the way relying too much on auto-exposure can affect your images. Or similarly in having someone else develop your B&W negs.

There seems to be packaged actions sold for almost every aspect on post-exposure image production these days and there may be danger that soon you yourself will not only have little control in the end but will not even really know how you got where you ended up.

Call me old fashioned, but adding constantly to my knowledge and expanding my depth and understanding of what goes into producing my images is what I need to build up the wisdom I desire to master my craft.

These books, and the different aspects they cover, are the what the zone system, developer process and darkroom process were in the pre-digital age. You can dive in as deep as you want or just wade into the shallows up to your knees. But as in the past, it seems the waders are generally the ones who seem most frustrated in why their work never seems to go over the top or be all they want it to be.

Joe's review sounds great. And if the book is half as good as the other Real Word books Fraser has been involved with were, I'm excited to pick it up and read it.

8 Comments:

Blogger Ken Tanaka said...

Thanks for the review, Joe. I had wondered how anyone, even Bruce Fraser, could fill a book with such a limited subject...I thought the answer must be 'big print and many illustrations'.

Personally, I'm somewhere between a button-pusher and tweaker. I use the Photokit Sharpening tools quite often for larger prints. They're the most refined and sophisticated tools of their genre, in stark contrast to Nik's awful, pricey blunt-force-trauma sharpeners. For Web images I've found that CS2's built-in "Smart Sharpen" is more than adequate.

Much as I admire that Bruce has devoted such a slice of his life to assembling this book, though, I think I'll pass. I'll sleep well knowing that the Pixel Genius boys are on top of this subject on my behalf.

11:47 PM  
Blogger Photo-essayist said...

Groan. Just reading Joe's synopsis of "Real World Image Sharpening with Adobe Photoshop CS2" makes me want to go throw cold water on my face. I, too, will pass on Fraser's book. Does anyone else wonder how it is "progress" when we increasingly make everything more complicated?

8:11 AM  
Blogger Ken Tanaka said...

I essentially agree with Richard's thoughtful comment, at least in the sense that learning to fish can often produce stronger long-term benefits than hiring a fisherman. Still, the PhotoKit Sharpening tools ("Pixel Genius" is the name of their developer) represents an excellent medium. These boys are the best fisherman in this stream and they enable you to participate in the process to any degree you choose. You want to just enjoy the meal? Fine. You want to see the meal squirm on the hook? Fine, come on into the stream.

If I was a fan of landscape photography I can imagine obsessing about how sharp a rock or leaf appears at 400 yards from the camera. For MY OWN interests, however, I'm much more inclined to devote my learning time toward honing my skills at recording ever-better images and compositions. Degrees of image sharpness accuracy, FOR ME, is somewhere toward the bottom of my top 5 list. Dull, uninspired, and poorly composed images don't benefit from sharpening.

Whatever aspect of photography makes one happy is the most important aspect...TO YOU. I always encourage people that their first mission is to find those aspects.

1:22 PM  
Blogger Joe Reifer said...

Richard and Ken both have good points - I tend towards Richard's view of going as deep as possible. Here's the irony: I prepared four versions of the same image in Photoshop to the best of my ability using four types of sharpening, and then made 8x10 prints. Unsharp Mask output sharpening only, Smart Shapren output only, two pass sharpening as learned from Bruce's book, and Photokit Sharpener. My two pass results and Photokit Sharpener were very close - but I slightly favored the Photokit Sharpener version. So Ken, I think you can sleep well with store bought fish. And Richard, I'll see you on the boat. :)

Cheers,

Joe

3:14 PM  
Blogger Adam McAnaney said...

I dunno. It seems to me that what is important is knowing what you want the final image to look like and knowing how to achieve that look. To the extent that learning about this stuff on the micro level helps you achieve that, so much the better. But I think prepackaged actions (for sharpening or anything else) are only bad if:

(1) you don't know what look you are going for, or what the result will look like when you apply an action. This is what happens when people apply an action and hope that something "cool" will result. This strikes me as being a lot like playing the lotto, except that when I play lotto, I at least know what I'm trying to achieve. ;-) $$$

or

(2)You know what look you're trying to achieve, but you don't know how to manipulate the action or image to get you there.

But if someone has no idea how an action works (in a technical, behind-the-scenes kind of way), yet still knows how to use it to consistently achieve a specific, desired result, I don't see any downsides.

OK, I take that back. I concede that learning about this stuff on a micro level can both help you understand what is possible, and better visualize what result you are going for. Plus, you're not limited by available actions, so you have greater flexibility.

Of course, that comes at a cost, in terms of time and the opportunity to develop other aspects of your photography. Which leads me back to what Ken said about picking what elements of your photography you want to focus on and develop.

I just repeated what everyone else said. This is what happens when I start typing before thinking things through. Ignore me. ;-)

4:28 PM  
Blogger mrkwr said...

Gimme a break, a whole book on sharpening? It's just another way to fetishise the the technology rather than focusing on taking, enjoying and sharing pictures.

-Mark

5:23 PM  
Blogger Olaf Ulrich said...

A whole book just on image sharpening? Yes, sure! I bought this book several weeks ago and boy, I'm glad I did.

To be afraid that reading another book will cost too much of your precious time and keep you from learinging more important aspects of photography is just ridiculous. Of course, everyone sure is entitled to pass ... but to anyone who does image post-processing Bruce's book is a must.

Many great photographers have hardly ever seen the interior of a wet darkroom and still were great photographers. Others always felt that processing film and printing images is just as important, and enjoyable, as exposing film. Today, many digital shooters don't care about digital post-processing; others do. And those who do should do it right, or all efforts put into exposing the sensor's photo sites would be moot.

Image sharpening is just as important an aspect of the whole post-processing chain as mastering contrast, tones, hues, and colour management. And it is as complex. Reading Bruce's book makes a new world unfold at your fingertips. Those who wonder how image sharpenening can fill a whole book simply have no idea yet what image sharpening really is. Understanding image sharpening and the tools and techniques is essential to anyone who wants to really master digital image post-processing---no matter if you do your actual sharpening manually, by home-made actions, or by purchased software. A fool with a tool is still a fool.

I can only recommend Bruce Fraser's book. It costs approx. the equivalent of three rolls of film incl. processing. Plus some time to read it ...

-- Olaf

5:30 AM  
Blogger Joe Reifer said...

Just for reference, the conversation about this book review spread to The Nocturnes Blog, and Brooks Jensen's Lenswork podcast. Further commentary here: http://www.joereifer.com/words/?p=56

Cheers,

Joe

10:13 AM  

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