RAW file conversion - what matters?

When I first converted to digital photography from film, I researched every RAW converter/photo editor I could find. And even though I looked hard at alternatives, Adobe Photoshop was the best overall converter and editor for me.  I sold a pretty nice lens to pay for it. Photoshop does nearly everything well, even if the interface isn't the easiest to learn.

I confess, I was pretty upset when Adobe decided to go with a subscription model.  I knew right away that wasn't going to work for me.  I'm an amateur.  I don't get paid.  I do photography for fun, but I don't do it every day.  

So I started researching alternative RAW converters.  The following information took me at least a year to gather.

I tried several, both paid and free: 

• Aftershot Pro (formerly Bibble), 
• Capture One,  
• Canon's DPP4 (only for Canon users),
• DarkTable 1.2.x (Linux/Mac only - I use Windows so I ran it in Linux via VirtualBox),
• DxO Optics Pro 9, 
• LightZone 4,
• Photo Ninja 1.2.5,
• RawTherapee 4.x,
• Photivo, 
• SilkyPix

I thought about Lightroom but I'm not sure I trust Adobe to keep that one free from subscription.

Some converters are easier to learn (and some have difficult learning curves), some are faster, some have nicer defaults than others, etc.  Some try to do everything, some do nothing automatically.  After months of experimentation, I came to realize I only cared about a few features:

• White Balance/Color space
• Highlight/Shadow recovery/Exposure
• Noise Reduction
• Lens corrections (if needed)
• Usability/speed

One of the things I have realized about these programs is that good or bad looking defaults don't tell you how well the program does using "best" settings.  Finding those best settings can take quite a bit of time and patience.  I am not convinced that I have learned how to get the best from each of the converters I've tried.

Some of the converters let you select from several demosiacing algorithms.  In practice, I found little difference between them.

I ruled out Lightzone because it seems to be missing a bunch of basic features, yet has a ton of fancy filters I don't care about.  I have not found a way to fix blown highlights.

White Balance/Color Space

Every converter can adjust white balance and color.  I think all of them have a spot tool where you can specify any region as neutral, and the app adjusts the color for the rest of the image based on that.  Most of the converters produce a decent default white balance, and I confess, that is an area where I struggled with Adobe in certain cases.  Every time I struggled with the white balance and color, I seemed to end up using DPP.  However, once I started playing with Photo Ninja, I found it really easy to make the colors either accurate, or have a nice 'pop' that for me is more difficult in the other converters.  I have played with RawTherapee more than most other raw converters, yet still find it very difficult to get the right color from it, and gave up on it for now.

I nearly gave up on Photivo early on due to a steep learning curve, but I gave it more time and got to learn the interface.  I found Photivo slower than most of the others, yet quite capable... until I realized it has limited color space options, and no matter what settings I have used, the saved TIFF looks very different from the preview in Photivo itself.  I do not have that problem with any other converter, so I know it isn't a calibration problem.  I tried adding ICC profiles for the color space(s) I wanted, and didn't see any benefit.  That was a showstopper, and eventually I threw in the towel on Photivo.  I hope they fix that in the future.  If they do, I will certainly give it another shot.

Highlight/Shadow recovery/Exposure

Highlight and Shadow recovery is a difficult problem.  The best highlight recovery I have seen is in Adobe, DxO, recent versions of Photo Ninja, and DPP (requires some fiddling in DPP4). The DPP4 highlight recovery is trickier than some; move the middle slider in the gamma adjustment curve if the normal highlight slider isn't good enough.   RawTherapee and Photivo defaults didn't work that well, but changing the blending mode gave me decent results in each of those two. DarkTable was pretty bad in the sample I tried (1.2.x), and was unable to recover any highlights regardless of settings.  That knocked DarkTable out of the race.  Likewise, I wasn't able to figure out how to do highlight recovery in Lightzone.

Noise Reduction

Most of the converters I tried did a very good job with noise reduction.  It isn't a distinguishing factor for me anymore.

I experimented with their various sharpening methods, and came to the conclusion that most of the time, I don't like capture sharpening, so that became mostly a non-issue.  If it is an issue for you, then I suggest you take a close look at DxO, DPP4, and Photo Ninja, which are superior to the rest.

Lens corrections

For lens corrections, I rate DxO the best (truly outstanding!), followed by Adobe, DPP, and Photo Ninja.  RawTherapee in theory can use Adobe LCP files, but somehow never seemed to handle CAs (Chromatic Aberrations) well.

I really like DxO, but after my trial period, I realized I had to pay more for the Elite version just because of the camera model I happen to own.  That bugged me and I decided it wasn't worth that much money over DPP, which is free.  But it has a lot of features and fantastic lens corrections available.  DPP only has corrections for Canon lenses, of course.  Photo Ninja appears to have more manual controls rather than lens profiles, but seems to also do a great job for my lenses by default, when needed, so I guess there are things happening under the hood based on the lens/camera detected.

Usability/Speed

Usability is clearly a matter of taste, but it is important enough to me that I had to mention briefly what I like and don't like.

Speed is more important perhaps. 

I ruled out Capture One, Aftershot Pro, and SilkyPix pretty quickly due to interface issues (no particular issues here, I just didn't like them).  They may well have some excellent features but I never got over the interface with them.  C1 in particular has a lot of followers, so don't let my tastes dissuade you from trying it.   RawTherapee appears to be very easy to learn, yet I have not mastered it in months of trying.  DPP4 is much improved over DPP3, but still not perfect. 

Photivo was trickier to learn, but I spent quite a bit of time with it. I found that by default you have to click a button to get the changes you made to execute.  It is quite slow in operation, but I like the interface. Too bad it doesn't appear to be actively developed anymore, and had the color space issues.  

At first, I didn't like the Photo Ninja interface that much, but a friend encouraged me to try it again, and patiently answered my questions.  Also, once I bothered to look, I found the help/instructions very clear and concise. After a little use, I learned to love how Photo Ninja operates. My favorite feature is the ability (in most contexts) to click between zooming to 100% and full-image views. That alone puts the usability of PN well above all the others.  PN has fewer options than some raw converters, but it has everything I care about; if I need more (such as selective sharpening, or dodging/burning, etc), I send the tiff to an editor.  PN is fast too.  I'm excited to see what the next major release looks like.

Summary

So in the end, I settled on two:  DPP and Photo Ninja.  I prefer Photo Ninja for nearly everything because DPP4 tends to overdo the contrast and saturation by default (where DPP3 was one of the most accurate converters on default settings).  I keep DPP around only because I found one example where Photo Ninja changed the color too much.  Also, DPP is slower than Photo Ninja, and DPP4 does not support my older images from older cameras, so I have both DPP3 and 4 installed.

Having used Photo Ninja for some months now, I like it more and more.  I found a bug related to my camera, and Picturecode listened, fixed the bug within a couple of days, had me test it further, and finally released a new version.  Name a big company that can do that!  They are very responsive to feedback.  Sometimes, they said "great idea, we'll work on that for the next release".  Sometimes, they pointed me to the manual.  But they always responded quickly and politely, and they always backed up their decisions with sound reasoning. They earned my respect and loyalty. The more I use it, the more I like it.

I mentioned not caring much about sharpening at the conversion step... but that has changed with Photo Ninja.  I actually use Photo Ninja's sharpening, often keeping the default settings.  I'm not sure how their algorithm works, but it avoids artifacts and halos very well, and sharpens on par with the best.  The only time I turn it off is when I need selective sharpening via masks/layers.

I like Photo Ninja so much that I barely use anything else.  I will sometimes use Photoshop for selective sharpening or dodging/burning, but now mostly it gets used for resizing images.  Once Photo Ninja improves the resizing feature, I feel I will use Photoshop even less, perhaps for just a handful of images per year.

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Update:  After all of the above, I found digiKam is available for Windows, and tried the raw conversion.  First impression is that it doesn't handle highlights any better than DarkTable or Lightzone.  I'll have to experiment with settings.

Update:  I keep reading great things about Iridient Developer.  When that becomes available for Windows and Linux, I'll try it.

Update:  I found a Windows version of DarkTable 2 on Partha's site, and found that version runs pretty quickly.  I'm still not a fan of having to import images and store changes in a database, nor do I like the sliders, but the quality has improved quite a bit and I'd say it is worth another look.

Update:  A friend pointed me to yet another free raw converter, Photoflow.  As of this update, it is in an early stage (0.2.6), but shows some promise in both quality and usability.

Modifying a centerpost to get your tripod lower

I used a fairly good, inexpensive aluminum tripod for many years.  It was stable enough under most conditions (especially with the legs not extended... this is common for me as I shoot a lot of closeups).  But as I got better gear, longer lenses, became pickier about sharpness and so forth, I decided it was time to both cut the weight and increase the steadiness.  I had read a lot of good things about carbon fiber tripods.  I did some research, including hands-on visits to the local store, and became convinced it would be a significant upgrade over the old tripod.  I picked the Gitzo 3530 because it had similar size/dimensions to my older tripod, which fit me well.  I was completely underwhelmed when I opened the box because it looked so similar to the old tripod, but I was astounded by the difference in quality.  Night and day really.  When I had my 300mm mounted on the aluminum tripod, legs fully extended, I could tap a leg and watch it wobble in the viewfinder... literally for seconds.  The Gitzo, under the same conditions, didn't budge.  No wobble whatsoever.  You can see vibration from the tap, but it stops immediately.  So I recommend a carbon fiber for anyone, regardless of the size tripod you need.

Gitzo has many models designed for many uses.  I wanted one that would do just about everything, from going to ground level, to fitting me standing up, while supporting my telephoto lenses.  Now, in a properly fitted tripod, when it is fully extended, you should not need the centerpost to look through the viewfinder.  No stooping, no stretching... with a head and camera mounted, it should just work for you.

The only problem is, the centerpost of the 3530 is way too long to get to ground level.  My old tripod had a split centerpost... you could use just a short part of it if you didn't need or want all 18" of it. Gitzo makes a number of models without centerposts, but, as I do a lot of closeups, I find a bit of centerpost adjustment very convenient, much easier than adjusting the legs (In closeup work, a tiny movement is a huge change in composition).  Gitzo's solution is to allow the user to remove the centerpost entirely.  The 3530 has a hook on the bottom of the post, and that can attach directly to the mounting plate.  It works, but it isn't convenient... you either have no vertical adjustment, or you have to take it apart in the field.  Gitzo sells short centerposts... but after spending over $600 (USD), I was reluctant to spend another $100 on another part.

I decided to cut the post to fit.

First, I measured how much centerpost I would actually use in the most extreme of situations, like standing up with the camera aimed skyward.  I found 8" (5" of travel) would do the trick, while still letting me get as close to ground level as I'd done with the old tripod.  Please don't assume my numbers will work for you... anyone who does this will need to make their own measurements. Measure twice, cut once. Obviously, once you make the cut, that's it.  By the way, carbon fiber is very easy to cut.

I didn't want to lose the hook, or lose the ability to remove the centerpost entirely.  There is a mount at the bottom of the centerpost where the hook screws in, and it is firmly epoxied to the interior of the centerpost.  I had to remove the epoxied part that was stuck to the mount by sanding it off the mount, which took some time and patience.  Once done, I simply epoxied the mount into the bottom of the shortened post.  It fits perfectly, and almost looks professional (I can see a hint of the white epoxy I used).  It seems to be just as strong as the original.   I can still remove the centerpost entirely if I want to get lower, I still have the hook, and I have all the centerpost I need.

Some say having a model without a centerpost makes the tripod more stable.  I have not noticed any problems in using the centerpost even at 1:1 magnification, or with a 400mm telephoto. I also have not personally seen any physical evidence that a centerpost, lowered all the way, is any less stable than a flat plate or a leveling base.  If someone learns of such evidence, please point me to it, I'd love to see it.    Gitzo tripods are well-built and the carbon fiber is excellent at absorbing vibrations.  As I write this, I've had the 3530 for over 8 years and it is still solid.

Review of the Kirk BH-1 ballhead

I've read some mixed comments online about the Kirk BH-1, and thought it was time to share my experience the ballhead.

I bought the Kirk BH-1 in early 2003. I've had it more than long enough to know it well, and to have given it a few dings and wear off a bit of finish. It works just like it did the day I unwrapped it, even if it isn't quite as nice looking. Strong, solid, smooth. I have 100% confidence that it will hold anything I can put on it. In a nutshell, it works very well and I like it. I have never regretted the purchase. It works and doesn't get in my way; I give it no thought in use and that's the way it should be. I've had other heads that would shift, slip, or poke me, so having something so well made is wonderful. My version is old enough that Kirk changed the clamp design, but I'm not sure if anything else is different vs the current model.


Prior to the BH-1, I had a Bogen/Manfrotto 3038 heavy ballhead. The 3038 was very strong, but not smooth, and so heavy that I did not carry my tripod as often as I should (the 3038 head weighed 4 lbs alone). The raves about Arca-Swiss style heads convinced me to upgrade.

One of the reasons I picked the Kirk over other models (such as the Arca-Swiss B1), was the orientation of the drop notch. Many competing models had the controls on the wrong side relative to the drop notch. I hold the camera with my right hand, so I want the ballhead controls easily usable with my left, with the drop notch opposite from me. I shoot a lot of closeups, and end up aiming down frequently. Only subsequent to my purchase have other brands followed that model.

Also, around the time I bought the BH-1, the Arca-Swiss B1 was notorious for having lockup problems. My Kirk BH-1 has never had a single problem in operation, and I've used it in every type of weather. As I'm sure most of you know, Arca-Swiss has since resolved the lockup issue.

At 2 lbs, the BH-1 is half the weight of my old Bogen, much smoother, and though I didn't want to admit it, the plates are much easier to deal with than the Bogen hex plates. For the life of me, I cannot understand why Manfrotto has not completely switched to A-S plates (As of 2013, they support a number of quick release systems). With all the more recent advances in ballheads since I bought mine, 2 lbs probably sounds heavy to a lot of people, but the weight certainly falls into an acceptable range where I don't mind hiking with it.

My model is old enough that the clamp does not have any provision for safety stops, nor a level. I simply have to make sure I clamp it down properly. I have a knob release (I am not sure levers existed when I bought it). I have not had any accidents, the clamp is simple and strong.

How strong is it? Once locked, the BH-1 doesn't budge, not one bit. There is zero creep (though there is settling as I let go, but that is tripod flex due to my input; like in all such systems, this is expected and normal). I have never seen a single movement while locked down in 10 years of use. Odd angles? I'd be more concerned about the tripod tipping over than creep. I've had up to a 400mm f/4 on it and it gives just as much confidence with that gear as it does with a compact setup like a Minolta XD-11 with a 50mm (yes, I was shooting film when I bought the BH-1). I've never even stressed the BH-1. Current models are rated at 50 lbs, but I don't recall seeing a rating when I bought mine. Photographers with heavier gear than mine were using this head when I bought it, so I wasn't worried.

How smooth is it? When the tension is on the looser side, it is quite smooth. It beats nearly everything else I have personally used. Only my Arca-Swiss Z1 beats it, but not by much. A number of other reviews I've read claim that there are a few models that are smoother, but if true, I'd say it isn't a concern if you use the ball loose and lock it down tight. If you use your ballhead loose, you'll be happy. I read one review that said the BH-1 is not smooth. All I can say is, my 10 year old model is smooth. That reviewer might have a lemon. However, the BH-1 isn't as nice when the tension is set fairly tight, and clearly the ball isn't as perfectly round as one might expect. As you move the ball around, the resistance increases and decreases, but it is still smooth.

For years, I simply left the tension setting fairly loose, relying on the main knob to tighten the ball. I never gave the tension knob any thought. More recently, I've read about people setting tension on their ballheads so that the ball does not slip even when the main knob is loose. I tried this recently, and found it just isn't workable on my BH-1. The tension knob requires several complete revolutions to go from completely loose to completely tight (so tight you can't move a thing). But the transition from loose to tight is very very short and sudden, and I have not found that "just so" tension setting. The tension control knob is not marked and not indexed, and it is also very easy to turn. My kids change the tension on me all the time. As a result, I expect some of you will decide to pass on the Kirk. This is the one part that Kirk could really stand to improve (maybe they did?). For my use it isn't an issue. FWIW, a close friend has a Really Right Stuff BH-55 and says the tension isn't very workable on that model either. Only the Markins and Arca-Swiss users seem to rely on that feature.

Also, with the tension set fairly high, I found that the BH-1 ball will shift when I tighten the main control, changing the composition (not just settling), depending on the angle. In doing closeups, this is unacceptable, so I just keep it loose. I can't tell you if that is just my copy, or a common design issue. I've read of this shifting/pulling with other brands too. I get the feeling that only a couple of the very highest end ballheads minimize this issue.

The panning knob just works. Loosen it to pan or adjust the location of the drop-notch, tighten it. It moves smoothly and locks tightly. I've carried it over my shoulder with a camera mounted and it has never come loose. No worries.

The bottom line is, this ballhead holds my camera steady with every piece of gear I've ever owned. The BH-1 isn't fancy, but it is a workhorse. It works well enough that I generally don't have to think about it when I use it, which is as it should be. Compared to previous heads I've used, that was a first.

Update:  After I wrote all this, dpreview came out with a very nice test of similar large ballheads. Unfortunately, Kirk wasn't included in this test: Battle of the Titans

Thoughts on a few quick-release clamps

I converted to an Arca-Swiss style ballhead and quick-release system over 10 years ago. As most of you know, this style is a dovetail design and relies on friction to hold a plate in a channel.  When I first started reading about them and took a look, I admit I was nervous about the plates sliding out of the sides.  Once I tried one, I was hooked on them and lost my concerns.  Given a properly-sized plate, they clamp down tightly and are completely secure.

Here are my thoughts on the few clamps I have tried.

Kirk (old style) screw-knob:

The first such clamp I ever used was a simple screw-knob type that came with my Kirk BH-1.  It is a very simple but strong design.  It takes a few turns to lock, but as it tightens, you can feel it grip the plate and you know it is secure.   My model is over 10 years old, and came with no safety stops... no pins, no channels as you find in more modern clamps.  But honestly, it doesn't need it.  Such things are for peace of mind only.  I have tried to push out the plates and was unable to budge them.  This clamp is more than strong enough for any application I have.  I love the large knurled design of the knob; very easy to grip even with gloves.

I have only two gripes with this older Kirk clamp (and they are nitpicks):

First is the length of the knob.  If you use the clamp with the knob pointing back at you, it can poke you in the face.  To be fair, this is common to most screw-knob clamps.  It is apparently a deliberate design decision; I have been told they are long to accommodate more plate styles, but I don't use anything that requires it.  To avoid being poked, I think most people use the knob on the other side, sticking out under the lens.  My old film body was short and the lens was always too close to the knob for comfort, so I solved the problem by using a square plate on the camera body and oriented the knob to the left side.  That worked for me for years until a friend convinced me of the benefits of an L-bracket.  Being poked in the face isn't a problem with larger DSLRs!

My second gripe is the speed of the clamp; it takes a few turns to tighten/loosen the clamp.  This wasn't an issue until I finally bought an L-bracket, and I wanted to switch orientations on the bracket more often.  One purchase leads to another, and the L-bracket got me looking at other clamp designs.

Kirk (new style) fast screw-knob:

The image is from Kirk's website.

Since I'd had such good luck with Kirk and thought I'd prefer a screw knob, I tried Kirk's newer fast speed screw knob.  I didn't like it, right from the start.  It didn't take much of a turn to unlock it, and didn't provide quite the same feedback as my slower screw during tightening.  It's faster, but it just didn't feel secure to me.  Also, I noticed that the clamp pushes the plate out of level when tightened, making the level totally useless.  The new Kirk clamp has channels that act as a safety catch when used with plates that have safety screws on the bottom.  And finally, I didn't like the more-rounded knob; it is harder to grip.

Acratech screw knob clamp:

The image is from Acratech's site

A friend of mine has an Acratech GP, which comes with a choice of either a lever clamp or a screw knob.  My friend has the double-speed screw knob. It has a nice knob and a quality feel to it.  I liked it better than the Kirk fast model, but it still doesn't provide the tactile feedback of my older slow screw knob.  My friend's clamp comes with a safety pin that will catch in the bottom of most plates and will help stop a plate from sliding out if it is partially loosened.

Markins lever clamp:

The Markins lever is nicely made with a quality feel.  It came with a Q20i ballhead I rented.  It is the first lever I tried and it was much nicer than I expected.  I appreciate the speed of locking and unlocking. It requires a bit of force and I don't see it opening by mistake too easily, but you could in theory catch the end of the lever on something.   My only frustration is that apparently my older plates have inconsistent widths and one of them wasn't totally tight.  I was able to push the plate out of the clamp with thumb pressure.  The fix is to get plates from one maker that are all the same width, and adjust it properly.   The Markins has a pin like the Acratech model to act as a safety stop with virtually any plates.

I also don't see the point of a level that is hidden under your mounted camera.  To use it, you have to level the clamp before you mount the camera.

Really Right Stuff lever clamp:

This is the clamp I ended up keeping.  Many people rave about RRS gear and now I understand why. I didn't expect to like lever clamps but RRS changed my mind.  I have the B2 LR II, which, as it was made after 2012, has a self-adjusting design that holds each of my varied plates securely.  I cannot push my thinnest plate out of the clamp they way I could with the Markins clamp.  Every plate (all Kirk plates) I own is 100% secure in this clamp.  I'm not saying every plate ever made will work, just that all of my Kirk plates work.

The lever wraps around the edge of the clamp and always ends up under your camera or lens, giving it more protection from an accidental tug (which requires a fair amount of force anyway).   The safety mechanism is the same as the new Kirk clamp; channels which require screws on the plates to stop an accidental slide.   The build quality is excellent; it feels beefy and secure in use.  While I would like an extra lock on the lever for my own peace of mind, I don't think it really needs one.  In actual use, I never give it any thought; I just know it is secure.

It has a scale on both sides of the clamp with marks every 1mm.  However, my L-bracket is fat enough that it covers most of the marks.  I can see the larger marks, just not every 1mm.

General observations:

A brand I would like to try, but have never had a chance, is Hejnar.  I like the short knob versions.

Another clamp design that looks interesting, but does not fit my Z1, is FLM's SRB-60 screw knob clamp.

In screw knob clamps, I found a trade-off between speed and my sense of security.  I'd rather feel secure.

One of the benefits of the lever clamps (this applies to both Markins and RRS, and a few other brands) is that the lever is low-profile, not jutting out above or below the clamp itself.  I can orient the RRS clamp in nearly every direction in my ballhead without hitting anything (it barely touches the base when the lever side is down in the drop notch, but this isn't a problem in practice).  Screw-knobs can hit the sides, base, or other controls on some heads, making some orientations awkward in use.  An L-bracket obviates most of those issues when they occur. 

On a monopod, I prefer a slow screw knob like my old Kirk clamp.  I think it is easier to tighten in that situation.

On a tripod, since I use an L-bracket, I like the speed of the lever.  If I didn't use an L-bracket, I would not care either way. 

What works for you is a matter of preference.

Sharpening techniques for digital images

Here are a few digital sharpening techniques I have found/learned over time.  None (so far) are truly original to me, I just wanted to put them all in one place.  Some people have favorite techniques and I am no different, but I enjoy learning new methods.

I shoot raw only, but I generally do not do capture sharpening during raw conversion.  I usually find it better to wait for the very last step, particularly if I re-size an image for web display.  Capture sharpening tends to make re-sized images look "crunchy" to me.

One of the primary motivations for me to search out a variety of sharpening techniques is to make myself independent of any particular tool.  When Adobe changed Photoshop to a subscription model with Photoshop CC, I realized paying a monthly fee to use software makes no sense, for me.  I am not a pro and I don't make any money from photography.  It's a hobby.  A passion, an obsession, but not a business.  Up to that point, I mostly used "Smart Sharpen" in Photoshop (I started with version CS2).  It works well but it is proprietary to Photoshop.  My goal was to find a method that works just as well that I can use in any image editor, because some day, I will be forced to upgrade my hardware or OS and eventually, my version of Photoshop won't work.  There is also a strong possibility that I will move back to Linux in the near future.  Actually, I gave up Linux at home when I bought my first digital camera, because GIMP didn't (and still does not as of my writing) support 16-bits per color channel.  Photoshop seemed to be the best option at the time, and I got used to it. 

Motivation aside, I'll get to the list and details:

I prefer to perform all sharpening on a duplicate layer so that I can undo it at any time.


Basic sharpen
A number of tools have an option called "sharpen".  Sometimes, it has no parameters whatsoever.  You get what you get.  This is basic and rarely very good.


Unsharp Mask (USM)
This is the most common "advanced" sharpening technique, available in most image editors.  You can do two things with it... detail sharpening and local contrast enhancement.  If you overdo the settings, you can create unnatural halos around your subject.  It can also increase noise.  I haven't learned it well yet myself, because Photoshop's smart sharpen was so much easier to use.

The strength setting refers to the amount of contrast used at the areas being sharpened.

Radius controls how far out the sharpen effect extends.

Threshold refers to how much difference in needed between pixels before the effect is applied.  Using Threshold 0 means every part of the image gets the treatment.

For detail enhancement, many seem to use a starting point of 300% with 0.3 radius.  

For local contrast, try a low amount with a large radius.



Edge mask sharpening
This uses USM, with a mask, so that only the edges of the image get sharpened.  It requires the channels feature. I'm still looking for a way to do it without the channels, because not all image editors I've tried have channels built in.  I've seen this described in a couple of places, and while it is a bit complex and time-consuming, I think it has the potential to work better than Adobe's smart sharpen.

1. Duplicate the layer you want to sharpen
2. Switch from viewing Layers to viewing Channels
3. Create a new channel and call it "edge sharpen"
4. Select the entire image, and copy it (Ctrl-A, Ctrl-C)
5. Select the "edge sharpen" channel and paste the image in.  It becomes B&W.
6. Run edge detection on the edge sharpen channel
7. Use Gaussian blur (small radius) on the channel
8. Use levels to increase the contrast (adjust black and white point as needed to help redefine the edges).
9. The next bit is where I'd like to have an easier way to convert this alpha channel to a layer mask.
10. Use Load Selection, and invert the selection.
11. Switch back to the layers view.  You'll see the areas with edges selected.
12. Sharpen with USM.  Use a high amount (the selection hides the halos, which is key to this method), radius 0.5 to 1, threshold 0.

Highpass sharpen
This is one of my favorites, and once you get a feel for it, is very quick to do.  It can create halos if used with too-aggressive settings, so I keep it subtle.  Some image editors have this method built-in, so you don't need these steps, though the settings should be roughly the same.  

1. Duplicate the layer you want to sharpen, and name it 'highpass'.
2. Run the highpass filter on the duplicate layer.  Adjust the radius so the halos are not too strong. I usually use between 2 and 5 pixels.  For a full-size image, I start around 5 pixels, while for a reduced (web-size) image, I start closer to 2 pixels.
3. Desaturate the high-pass layer (to avoid odd color shifts).
4. Change the blending method of the highpass layer to 'overlay' and adjust the opacity.  I usually end up around 40%.  You can also use 'soft light' for a weaker effect, or 'hard light' for a stronger effect, depending on your taste.  Most image editors that offer layers and/or masks have those blending options.   As long as you save the image with your layers, the blending method and opacity are adjustable.

Bilateral sharpen
This method sharpens textures more than the edges, because the bilateral blur (surface blur in photoshop) leaves edges mostly intact.  The technique is similar to the highpass sharpen.  Not every editor has the surface blur feature.  The blur step is noticeably slower than other blurring methods.  Depending on your computer speed, you might want to go get coffee while it works.

1. Duplicate the layer you want to sharpen, and name it "blur".
2. Run the surface blur filter on the blur layer.  Start with radius around 6 pixels and threshold 15.
3. Subtract the result from the original layer
4. Copy the difference into a new layer (Ctrl + Shift + Alt + E)
5. Blend the difference layer into the original using "linear dodge (add)" and adjust the opacity as desired.

Selective Sharpening
With any sharpening, and given an editor that can handle masks, you can create a mask to block out additional parts of the image you don't want sharpened.  


Other options
There are some good free raw converters, and some of them have sharpening options I've not seen anywhere else.  As I don't do capture sharpening, these are of limited use to me, but might be useful in someone's workflow.

RawTherapee has Unsharp Mask and Richardson-Lucy deconvolution methods.  R-L deconvolution is interesting and sharpens well, but adds quite of bit of noise if you use too much strength.  

Photivo uses Wiener sharpening by default, but also has Unsharp Mask and Highpass methods, as well as a couple others.  I have not learned how the Wiener filter works yet.



Links

Notes on sharpening
Thom Hogan's Sharpening 101