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Many photo editing software titles allow for sharpening, but there are often several options, only one of which you want to use.
The most common mistake that I see when people are post processing their images is that they oversharpen their work. The amount of sharpening needed for an image is very subjective, but professionals agree that there is a limit to which you should sharpen your images. Stock photo agencies will not take oversharpened photos, nor will most publications. Art is a different story, and indeed, this is what many people classify their photography as. After a while, it becomes a sticky area of discussion.
In this tutorial, we'll do the following:
1) Learn about which images need sharpening, and which are likely not to.
2) Learn about which method of sharpening to use, and how to use it.
3) Learn how to tell if you are oversharpening your images.
4) Learn how to selectively reduce sharpness in certain areas of your image using the history brush.
1) Suggestions for what and what not to sharpen
First, I'd like to suggest the types of images that are not often sharpened, or those that I would recommended not be sharpened.
Portraits, par exemple, are images that should be sharpened with great caution. Human skin, by nature, is something that is not necessarily flattering to see in extreme detail. The camera and lens can bring out much more detail than we're used to seeing, and this can only be exacerbated by sharpening the image. The face and eyes are usually the main point of focus in a portrait, so take care to focus your camera in on them. They may need to be slightly sharpened later (along with the hair). The other details may need to be softened, not sharpened, so don't touch your remote, as I'll explain how to do this soon.
Sunset and sunrise pictures - anything with strong directional lighting needs only minimal sharpening. During the early morning or evening, we see silhouettes or outlines of objects, nothing with hugely defined lines. If it's a landscape with well-lit detail, then you may want to re-think this.
sharpening, but the birds and the buildings in
the background could be slightly sharpened to bring out detail.
Otherwise, almost any image could benefit from a little bit to moderate amounts of sharpening. Landscapes with a lot of grass or trees are great so sharpen up. At long distances from the camera, trees and grass are not resolved very well by the camera's lens and imager. These need to be sharpened more than other things we typically sharpen. (However, be careful sharpening landscape shots - you don't want to oversharpen clouds and/or sky as it makes them look unnatural.) Sports and action images can benefit fron modest amounts of sharpening as well.
2) Which method of sharpening do I use? How do I use it?
One common mistake is when people use the photoshop (or other program) filter that says "sharpen" or "sharpen more." There is an option near those that is called "Unsharp Mask." We like to call it USM for short, but don't get it confused with Canon's lens focusing mechanism, the UltraSonic Motor (USM). The term Unsharp Mask originates from film darkroom use when physical tools would be used to bring out local contrast in areas of an image. Unsharp Mask is, by far, the most commonly used and control-able filter to sharpen digital images.
The one absolutely essential thing to learn about sharpening is that you cannot make an image sharp if it was originally soft when you took it. Unsharp Mask is not magic. It utilizes the detail already in the image to bring out (what I earlier referred to as) perceived sharpness. I (not to mention, others) can tell if you overuse this tool to try to fix a poorly focused image! Soon we'll learn how, but first we've got to learn how to use this mysterious tool/filter.
In photoshop, the Unsharp Mask filter is found in the "Filter" menu under "Sharpness."
The dialogue box looks like this:
"Amount" is how much sharpening you want to apply. "Radius" is the most important box to look at, as it denotes the type of sharpening you will be applying to the image. "Threshold" is, in short, the sensitivity of the image to the tool.
Let's start with "Radius." If you have an image with very small details you want to bring out, you should set the radius low. For very small details, I use a 0.2 pixel radius. For larger (but still small) details, or images that are slightly soft, I use a larger radius, between 0.3 and 0.9 (or 1). This will enhance the small details in an image. If you use a larger radius, you can enhance the contrast of the entire image, with emphasis to detail areas. For doing so, I would use something between 5 and 50 pixels.
Now, with "Radius," the "Amount" is what you use to control how much of your sharpening is applied to the image. This is probably the easiest part to remember, and is very obvious if you get it backwards: The larger the Radius, the smaller the Amount is needed. The smaller the Radius, the larger the Amount is needed. For anything under a 1 pixel radius, you'll need to use a pretty large amount (percentage) to notice any difference in your image, something between 100% and 500%. For a large-pixel radius, you can use a smaller Amount, e.g., something between 1% and 40%.
The "Threshold" is easy. If it is set low, the image will be affected more easily by the sharpening. I usually keep the threshold set between 0 and 5. I almost never touch it.
Now, all of this information is useless without an example of how to use it in a workflow. I am a fan of often using a 2 step USM application - one step with a high pixel radius sharpening to bump local contrast, and another with a lower-pixel radius to bring out the little details in the image.
Note that sharpening should always be the last step in your workflow. I do not recommend sharpening full-sized images if you intend on resizing them and posting them online. All of the specs I have given for sharpening are for images between 600x400 and 1500x1000 resolution. Always save a copy of your work, never overwriting the original copy. If you are going to be sending a file off for print, you'll need much larger pixel radii, even for small details.
Let's try one out!
Here's an image that has gone through a full workflow but has not been sharpened yet. It has been resized to 900x600 pixels:
Step 1: A first-step, high-pixel sharpening. This boosts the dramatic contrast in the picture, but not enough to kill all of the blacks or blow the highlights like using another method might.
Step 2: A second-pass, smaller-pixel sharpening. This will bring out some detail in the leaf and the spider webs.
Voila! We've made it - a final image, ready for posting on your online gallery or friendly DSLR DI board!
Stick with us though; this is a modestly-sharpened image. Let me show you what happens when disaster strikes (and it strikes more often than you may think!) Read on....
Oversharpening usually originates from doing one of two things:
•Using the "sharpen" or "sharpen more" options in your editing software.
•Using too high of a USM pixel radius with too much power (amount/percentage)
Here is the above image sharpened excessively (for small details) with too high of a pixel radius:
Here's that same image that was sharpened too many times with a low pixel radius:
How do I tell if I've oversharpened my image?
Color noise and tiny artifacts (that normally wouldn't be seen if left alone) are brought out in oversharpening. While multiple low-pixel sharpening passes can be done, the above was an example of how far not to take it. The excessive high-pixel sharpening will cause halos around objects. I would say that this is the most common error. It happens a lot with portraits against solid-colored backgrounds, and you end up seeing halos around the person's head, hand, etc.... If in doubt, back it off a little bit and look at it in comparison to your original image.
4) Selectively reducing sharpness with the history brush
While the history brush could have an entire tutorial of its own, the history brush has a great purpose for touching up the sharpness in portraiture or other photos that have different sharpness requirements for every section of the image.
Let's take a look back at the types of images that might need this special treatment:
•Landscapes that have trees and sky in the same image
•Images that need low-pixel sharpening, but have places where artifacts might be brought out in empty space or in undesirable areas
Here's our original portrait:
We want to do some low-pixel sharpening to the entire image to begin with. Look only at the face/eyes/hair when doing this part.
Now, open up the history pane, it looks like this:
See that little brush and the arrow at the first step for this image? That's the anchor for the history brush. It allows you to paint over any area of the image, and the image will be restored to that history state. Click the history brush box for the state right before the sharpening began, and it will look like this:
Now, locate the history brush on your tools panel:
Use this brush to brush away the sections of the image you didn't want sharpened. In this photograph, I want sharpness only in the face/hair. All other skin and clothing (and the tree that the camera back-focused on) should be brushed back to it's pre-sharpened state. With that, the final image looks like this:
The subject is properly sharpened in the right places, and unnecessary sharpness in distracting locations has been taken away!
Take a look at the tutorial for the history brush if you have any more questions.You can acheive a same effect with a greater degree of control (with added difficulty/complexity as well) with a layer mask. Read about layer masks here.
Proper sharpening should leave little or no trace of its presence in your final image. I like to say this as a loose rule of thumb: If anybody else can tell that it's been sharpened, you've done too much of it.
Thanks for reading!
There's a great tutorial from Katrin Eismann, the author of Photoshop Restoration & Retouching and co-author of Real World Digital Photography:
Fritty has kindly put them all together, to spare the cat some work...
Technique! Week 1 -- Rule of Thirds
Technique! Week 2 -- Framing Techniques
Technique! Week 3 -- Masking with Black and White
Technique! Week 4 -- How to place yourself in an image
Technique! Week 5 -- Creative Backgrounds Using Masks
Technique! Week 6 -- Lasso this!
Technique! Week 7 -- Patterning
Technique! Week 8 -- Painting From Pictures
Technique! Week 9 -- Breakup
Technique! Week 10 -- Emboss
Technique! Week 11 -- Lead With Lines
Technique! Week 12 -- Paint By Numbers
Technique! Week 13 -- Adding Text
Technique! Week 14 -- Curves
Technique! Week 15 -- Selective Focus Using Color
Technique! Week 16 -- Silhouette
Technique! Week 17 -- The Idea Edition
This site will explain different ways to convert your Digital Images to B&W properly as well as explain how to add that film grain to your B&W images.
That silky smooth water effect is all about exposure and understanding how light will effect the exposure, be it digital or film. To get it right takes in many factors including the ambient light, stability of the shot, and tools to lengthen exposure as need be.
But first a primer on exposure, and how it applies to this type of shot. Each point, be it digital, or film, experiences exposure due to light. The exposure is cumulative, and a one way trip from dark to light. Every time a bright point hits the plane, that point is that much brighter, and will NEVER get darker.
This is where is gets fun. Water is chaotic, and depending on volume, will create a chaotic number of bright points over a period of time to create the cloud-like illusion. The amount of chaos is a function of the volume of the water, and the disturbance in it's path. A slow moving stream can take 8 seconds, a river at flood stage 1/5 sec.
The question begs, how to get 8 seconds on a sunny afternoon? Well, likely you don't. You can use neutral density filters to help, or at times, a circular polarizer to limit the reflections you don't want. But your best bet is late afternoon or early in the morning (I've heard of such a thing), or overcast, or best, while it's raining. Yes, while it's raining.. the water droplets from the rain give a nice tone, and make the scene more chaotic, often lessening the needed exposure.
Tools I use: Camera with exposure control, solid tripod, remote shutter, circular polarizer, and a nice scene with the right light. Optional are the ND filters JIC the light is to much.
»Everything you want to know about -Selections- PS
[Tutorial] The making of an image
[Editor's note: Click on images for full-size versions.]
I have been asked to reveal my secrets on the processing of this image I recently posted to the gallery; since there was nothing too different from my normal workflow involved in its creation, I decided to use it as an example in a tutorial about it. This is meant to help beginners at post-processing; experienced users might find it boring, redundant, and even inefficient in some of its stages. I'm posting it because it worked for me in this particular image, and it can provide helpful ideas for those trying their hand at post-processing. It is freely given, and no offense is taken if it is freely ignored. This is a long post, so brace yourself!
The software I am using is Photoshop CS 2; you can do pretty much the same thing in older photoshop versions (except perhaps for 16-bit processing), PSP, GIMP and God knows how many other packages.
Here's the picture I posted:
KONICA MAXXUM 7D
15mm 1/25th F22 ISO100
So, how de we end up with an image like this? Well, this is not the view out of my window, so for starters you have to get your butt out there. I also didn't stumble on this location by chance; a bit of research was involved. Although I didn't know I would find this particular spot on the shores of Pyramid Lake in Jasper National Park, I knew that the best time of the day to photograph reflections was in the morning, when the sun hits the mountain ranges head on and the mid-morning breeze hasn't yet disturbed the still waters of the lake. Whenever photography is the prime motive of a visit to a particular place, I at least take the time to look at the map, identifyithe various attractions and landmarks, and figure out whether they will be best lit in the morning or afternoon.
The second element is the light; you only get this kind of light in the early morning or late afternoon. To obtain images like this, there is no substitute for getting up early, period. This particular picture was shot at about 8:30 am, and that was the second session of the day (the first one had been shooting the sunrise at Mount Edith Cavell at 5:30 am). Sleep in and you'll miss the light.
Once you are on location at the appropriate time, your next task is to look for a pleasing composition. There are no hard and fast rules about although there are some helpful guidelines. In this image, two things work particularly well. The first one is a judicious use of the rule of thirds:
Notice how I divided the field of view into thirds, both horizontally and vertically; most elements of interest are placed near the intersections of the blue guide lines, and all are far from the middle section of the picture. The boulders, the mountain ranges, the clouds and the rocks seen trhough crystalline water all add interest to the scene, and the eye keeps wandering from one to the other; place one of them smack in the middle and it will capture all the attention, detracting from the rest of the scene and making it boring.
The second compositional element present in this frame are triangles:
The eye naturally follows the lines along the sides of triangles, which also evoke a feeling of balance. If you want to add a sense of strength and stability to your images, try circles instead. If I had placed all lines (shore, mountains) parallel to each other, the scene again would have been boring.
Finally, at the 15mm focal length I used, every distant element becomes really small, so it is imperative to add an interesting foreground, in this case beautifully provided by the boulders.
Once you are happy with the compostion, it is time to shoot your frame. In landscape photography, you want to get as much of the scene in focus as possible. That means stopping down your lens as much as you can without encountering diffraction effects; in my Sigma zoom, that happens at f/22. At such small apertures, however, shutter speed drops big time, so a tripod is mandatory. Even if you get a shutter speed higher than that, you will still want to use a tripod to preserve fine detail. Your 20x30 enlargements will thank you!
Next, figure out the optimal focal distance, which in landscape photography is the hyperfocal distance of your lens. Focusing at hyperfocal distance ensures that everything behind the focal point remains in focus, and a good bit in front of it too. You'll need a hyperfocal distance chart for your lens; in this case, the hyperfocal distance was somewhere in the boulders. Notice how the mountains are still in focus, although I am not focusing at infinity.
Set your camera to RAW mode, then shoot. And, for heaven's sake, BRACKET YOUR EXPOSURES! I am not going to be back in this location anytime soon, it wouldn't have been nice to get home and find out a bunch of nicely overexposed pictures, would it? Memory is cheap, moments are priceless. BRACKET!
OK, so we are back home, pictures downloaded to the hard drive. Grab a cold one (thanks Cramski for the tip!) and start post-processing.
Since we shot the image in RAW, we will need to use a RAW converter. I will use Photoshop's Adobe Camera Raw in this example. Open the file and you will find a screen like the one below:
A few things to note here:
- I will be working in 16-bit mode (lower left circle). This will allow me to preserve most of the information captured by the sensor, and will minimize any post-processing artifacts.
- Most other values are set to what I found works best for my camera; experiment with yours. ACR has a few standard profiles for the most common cameras.
- I normally don't touch saturation at this stage. I found that the saturation command in Photoshop itself works much better than the one in ACR.
The two commands you will use more often are the temperature and exposure ones. Here I am deliberately underexposing the image by 85% of a stop; this is because I will use two different versions of it to expand dynamic range (more below). The other is the temperature command; I am shooting for a "warm" look on the stones here, and so I am increasing the temperature to a hefty 6000. This value is way too high for most images; you will want to stay at 5100 for sunny shots, and 5500 for ones in the shade.
I said I would develop two versions of the image, one underexposed and the other overexposed. This is done to capture maximum detail in both shadow and highlight areas. My technique here is one of many; some people may manage it out of a single development; others will use more than two developments. Others yet will shoot two different frames (but in landscape photography this is tricky, as the slightest movement of the tripod between frames will show).
Here's the second conversion:
Note how it is now overexposed by half a stop; since this version of the image highlights everything but the rocks; I am dropping the light temperature to a more normal 5700.
Once you have your two conversions open in Photoshop, select the entire dark image and paste it on top of the light image. This will create a second layer, called "Layer 1." Now we will try to combine the best elements of both layers using layer masks; the goal will be to have the darkest parts of the overexposed image and the lightest parts of the underexposed image surface in the final product.
Select this layer and add a layer mask by hitting the "add mask" button (shown with a red circle). The layer mask becomes linked to Layer 1.
The next step is to select the bacground layer, select all its contents, copy them, and paste them onto the layer mask. To do this, control-clik on the white square representing the layer mask (Macintosh: option-click). You should see this black and white image representing what you have pasted into the layer mask.
The layer mask contains the luminosity information of the light frame; the dark areas of the light frame are the ones we want to preserve from the overexposed image; by using them as a mask on the dark frame, we filter them out of the underexposed image.
If we were to keep the mask as is, the image would look unnatural. To smooth things out, we will blur the layer mask. Select Image -> Adjustments -> Gaussian blur. For a 5-6 MP image, a value of 40 should work fine.
Next, click on the background layer, and you should see the blended image. It should already look better than any of the original frames, but we still have some ground to cover. The first thing is to get the brightness and contrast just right. To do this, forget that mistake of programming that were the brightness and contrast sliders; we will use the curves tool instead, which gives you much more control with minimal loss of information.
One of the advantages of this digital blending techniques is that you can use separate curves on the light and dark frames. Select the background layer and go to Image -> Adjustments -> Curves.
Here I am applying a classic "S" curve, darkening the dark areas and lightening the light ones. This adds contrast to the image while, if used judiciously, preserving the highlghts (not that we care much, the highlights are coming from the dark frame anyways).
Then select the dark layer (Layer 1), and use the curves command again.
Here the curve is a little different. Since this layer contains the highlights information, I am not touching the upper part of the curve. I am still darkening a little the dark areas, so that they will blend a little better with the background layer. Play it by ear (eye?) and see those tones come alive!
It is time to flatten your image now (Layer -> Flatten Image). From now on, we will work on a single layer.
There are a number of ways to get more vivid colors, all the way down to sophisticated and expensive actions. We'll take the easy road here: Image - Adjustments -> Hue/Saturation. Set the saturation slider to +10.
Be careful not to overdo saturation, or your images will look unnatural.
Next for color correction. Those rocks look awfully yellow to me, and I want a reddish effect. Go to Image -> Adjustments -> Color balance.
You can work in three different luminosity areas; the midtones are the "general" playground, and will suffice for the correction I want. I am increasing the Red and Blue sliders (hence subtracting Cyan and Yellow), which has the effect of turning the image a bit redder without warming it up too much (because I am adding blue).
Voila! The only thing left to do is to sharpen your image. What kind of sharpening you do depends on the intended use of it. Suppose you want to print the image; in that case, I suggest you set the viewing size to 50% of actual size; this will give you a good approximation to the sharpness of the printed image. Choose Filters -> Unsharp Mask.
I tend to set the radius to 0.5, using higher values only in extreme cases. 100% is a good bet for a 6 MP image, give or take. Look at the rocks for reference, and take care not to oversharpen.
Before saving, do not forget to convert your image to 8 bits, otherwise you won't be able to save a JPEG file.
If, instead, you want to post the image on the web, go to Image -> Image size. Make sure the "resample image" and "constraint proportions" boxes are checked, and set the image size to your liking. Here I am going for 800 pixels wide. Don't pay attention to the DPI box.
Now you have to sharpen your web image. Since you are dealing with a smaller file, you need different values for the unsharp mask filter. I found that 50, 0.5, 0 work best for my web images. Feel free to try your own settings and let me know what you come up with!
And that's it! Thanks for bearing with me, and I hope this has been useful. Above all, remember that the most important thing in all this process is to have fun creating your images. I enjoy every step, from the planning to posting them online. I hope you do too.
Steps to a great sunset shot:
1. BE THERE. There is no way you can get a great shot without getting there before the sun goes down. You need compositional elements, trees, reflections, boats, etc.
2. TAKE A TRIPOD. If you stick around until after the sun goes down you will have more vibrant colors in the sky, but your exposure will drop quickly. Take a tripod, or at least a monopod so you can have sharp images from the foreground grass and rocks, to the trees and clouds miles away.
3. SHOOT RAW. If your camera can process them quickly, shoot raw. This will let you play around with layers and masks later on to richen up the color and deepen the shadows or bring out detail in the foreground in certain areas easier than manipulating jpg images.
4. TAKE LOTS OF PICTURES. Bracket your exposure, expose for the sky. Your camera's meter will read all that dark foreground usually and blow out the sky and clouds, so use manual mode if you have it available. Review your images quickly as you shoot and adjust exposure as needed to get close to what you want.
5. DON'T BE AFRAID TO EDIT. Once you get back to the computer you will probably need to do some work to get the colors to pop like you want.
Once I did all of this I resized, sharpened, and uploaded here and on my site.:p
»Punch up those photos.......fast and easy.
»Punch Up Those Photos (Gimp Style)
There are certain adjustments that you may want to make, but not image-wide. I think of it as being like a virtual edge trimmer for your image - you do the overall cleanup of the image, and then can use the history brush to selectively fine-tune the rest of your picture.
Say you sharpen up your image and then want to go back and de-sharpen certain areas - this can be done with the history brush. Say you change the levels, curves, or saturation on your image and wish to remove the effect on certain portions of the image - this can also be done with the history brush.
The one caveat that can be frustrating about the history brush is its inability to revert back to states if the canvas/image size was different. This means that you can only go back in history in the period of time where the image stayed the same size. For example, say you have an image that was 1024x768. You apply a boost in saturation and then reduce the image size to 640x480. You cannot use the history brush to brush out this saturation in the 640x480 image.
Now I've made it sound like applying the history brush is difficult to do. In fact, it's not hard to use at all. The above was simply a forewarning for a catch-22 with the tool that we all fall susceptible to at times.
Now, let's get to using the history brush!
It almost doesn't matter what effect you apply to your image as long as you keep the same image dimensions.
For this example, I'll be using a gaussian blur on one of my images, and then will use the history brush to selectively isolate the subject (leaves) from this blurryness. This is probably better done with a quickmask or layer mask, but for the sake of demonstration I'll be using the history brush.
For starters, you need to be familiar with the two most important aspects of the history brush: how to select what history state you will be reverting to, and where the tool itself is.
First, I've applied a 3 pixel gaussian blur to my image.
Here's what that looks like:
You are going to want to anchor the history brush at the point just before the undesired effect. Click in the box next to that state (highlighted for demonstration):
Click on this tool (again, highlighted for demonstration):
Just like with any other brush, you can set the size, shape, and hardness of the brush. Brush over the section of the image that you wish to remove your effect from:
Here is the final result:
I've basically un-blurred all of the leaves in the image and the background maintains its ultra-blurryness.
Thanks for reading!
How to paint mountains
•Air brushing landscapes
about gradated layer masks in photoshop:
These are useful if you have an image where you need different levels for the foreground and sky, but don't want to do a sloppy job. This tutorial will help make a gradual brightness transition between foreground and sky.
»[Tutorial] "how to make your photos appear older" (by me)
See this tutorial thread: »[Tutorial] A "knockout" technique (56K warning!)