Sharpening Your Wildlife Images

I trust that you had a fantastic Xmas and that you have settled into somewhat of a normal eating pattern after the obligatory overindulgence of the silly season!  We had a  fantastic time with family and now, being back at the lodge, it already feels like months ago.  Great memories though.

Fresh from a few days off from the blog here we go again.  After a number of requests I decided to do this post.  Sharpening is something that can make a good image great but it can also, if done incorrectly, make a great image look over processed which can make that image crash and burn.  Sharpening can enhance texture and details in your wildlife images and is, I believe, one of the critical parts of the digital workflow.  The decision as to how much sharpening is enough or too much is a fine balance and something that gets easier with practice.  For the purposes of this post let’s look at two types of sharpening that you can use when processing your images.  They are:

• Unsharp Mask – This is probably the most commonly used way of sharpening even though it really has nothing to do with sharpness.  The unsharp mask (USM) purely increases the edge contrast between neighboring colors in an image.  This can lead to a subtle shift in color tones in your image and also a slight increase in any noise that might be present.
• High Pass Filter - A slightly more advanced way of sharpening which is done on a new, separate layer meaning you can alter many of the variables afterwards.  A high-pass filter gives you more control over your sharpening and as it is done on it’s own layer there is virtually no changes to the color tones in your image.

At this point it is worth mentioning that there are some amazing filters and plugins such as Nik Software’s Sharpener Pro 3.0 which are phenomenal and can make your (sharpening) life a lot easier.  I do use Sharpener Pro 3.0 from time to time but for the majority of my images I sharpen using a high pass filter.  If you have some extra cash it is definitely worth it!

Anyway, here goes. Let’s look at one image and how you would go about sharpening that image by using both of the methods mentioned above.  Remember that ideally sharpening should be the last step in your post processing so for now let’s assume that I have done all the things like color corrections, exposure and curve adjustments already.

First up, let’s use USM.  Even though it is not technically sharpening your image it is very easy to use and you can get some very decent and usable results.

Unsharp Mask (USM)

The image above shows the original RAW file of an elephant’s trunk.  To access USM click on ‘Filter‘ – ‘Sharpen‘ – ‘Unsharp Mask‘.

Once you have clicked on ‘Unsharp Mask‘ the following box will open up.

You will see that you now have three sliders that you can use to sharpen your image. By keeping the preview block ticked you will be able to see the results of the sliders directly on your image as well as in the little preview box showing you a close up of a selected area of the image.   Very handy.

To successfully use USM you need to understand the three sliders and how to use them.

• Amount:  This is given as a percentage and basically refers to the amount of contrast that gets added to the edges.
• Radius:  Refers to the size of the edges you will be affecting.  A smaller radius will enhance smaller scale details.
• Threshold:  Can be used to sharpen more pronounced edges while leaving softer edges untouched.

That’s is about it.  All you need to do now is to use the sliders, based on the above, to get the ideal amount of sharpening for your image.  What is ideal?  Hey, that is completely up to you but remember that the goal is to make the image pop just a little yet still look natural.  As a guideline set your sliders to the following:

• Amount: 75
• Radius:  1.5
• Thershold:  1 or 2

From here start by playing with the amount, watching your image all the time.  You are looking to get an increase in sharpness without getting a halo effect around some of the areas in your image.  Look at areas that include branches, fur and around the eyes.  (In my elephant trunk image I used the little hair around the trunk as my guideline.)  From here start playing with the radius.  Start with a lower setting and see if you can still get good results.  Different images will ‘require’ different adjustments to the radius slider.  Once you are happy with the results you can try and adjust the threshold slider but I almost never change the threshold.  A setting of 1 or 2 gives great results but always check it out ‘just in case’.

Thats’s sharpening with USM.  Very straightforward and it is capable of giving good results but remember that it can affect color balance and noise in an image.  We will compare results at the end of the post.   Next up, sharpening using a high pass filter.

High Pass Filter

As a high pass filter gets applied to it’s own layer, the first step is to create a background copy of your image.  To do this open the layers tab and simply right click on your original image (by default called Background) and select duplicate layer. You can then rename the new layer to something like ‘high pass’ but I didn’t so it keeps the default name, ‘Background Copy’.

Once you have your two layers, highlight the new layer (background copy) by clicking on it as shown above.

From here you select high pass filter click on ‘Filter‘ – ‘Other‘ – ‘High Pass‘.   If you cannot see the ‘Other‘ tab scroll all the way down the list and click on ‘Show all Menu Items‘ which will then open your entire menu system.

Once you select High Pass the following box will open.

You will see that compared to USM the High Pass filter only has one slider – Radius.  Before you start playing with the slider, again make sure that the Preview block is ticked which will give you a live preview on your main image.  Once ticked you will see a grey layer on top of your original image.  This is the high pass filter so don’t worry.

Now you are ready to start playing with the slider. All technicalities aside, the easiest way in which to judge how much of the high pass filter to apply to your image is to take the slider to the right until you start seeing colors shining through the grey.  You can see this in the image above where there is some color starting to show through on and around the elephants trunk.  From here slowly slide the slide to the left, watching the image all the time, until you can see the edges of your image with as little as possible color shining through.

In the above image you can now see that the edges of the ellie’s trunk is just visible yet the colors that were shining through earlier is gone.  That is what I was looking for.  All edges, no color.

As a guideline, for high resolution images of above 8 megapixels you can start the slider between 4 and 5 and work your way down, or up, from there.  For smaller sized images, such as those you might want to use on the web or in email, you can start between 1 and 2 and take things from there.  For example, in the elephant trunk image I ended up using a Radius of 1.1 as it was a small web sized image (700 x 700).

Now that you are happy withe the edges on your grey layer you need to blend the sharpened layer onto your image.  To do this click on the two arrows above your layers (where you created a background copy earlier on).  The default is ‘Normal’ but when you click on the arrows you will get the following screen.

The three options, as circled above, are:

• Soft Light
• Overlay
• Hard Light

The above options tells Photoshop how intense you want the sharpened grey layer to be blended onto your original image.  I normally use Soft Light as it is nice and subtle yet gets the point across but play around with all three options.  Either way, as you have created a new layer you can still adjust the opacity of the sharpened layer afterwards.

Once you have selected your blending option your screen will look something like this.

You will now see your final, sharpened image as well as the two layers and your choice of blending mode.  Now this is where the high pass filter takes a step ahead of USM.  Because you created a new layer and applied the sharpening to this layer you have the choice of changing the feel, intensity and ultimately look of your final image.

If you are not happy with the look of your sharpened image you can go and change the blending mode by clicking on the two triangles again.  You can also change the opacity of the sharpness layer by using the opacity slider right next to the blending mode.  By slowly decreasing the opacity you will in fact be decreasing the intensity of the sharpness you have already applied to the image.  Think of the options.  Once you have selected your initial amount of sharpening you have three different blending modes to choose from.  Each of these can then be adjusted even further by using the opacity slider to adjust the intensity.  That leave many many sharpening options!

Once you are happy with your image and are ready to save the file, you need to merge the two layers together.  To do this simply right click on any of the layers and select ‘Flatten Image‘.  All done.  From here you can save your file as a TIFF or JPEG and impress your friends and family with your amazingly sharp and crisp wildlife images!!

So.  Which one is better?  USM or high pass filter?   As with most things in photography, there is no right answer.  It depends on what works for you and what your vision is for your image.  I personally prefer using high pass filter as it gives me a lot more freedom and I can customize the way I sharpen my images to exactly what I want but USM can give you some great results as well.

The best I can do to answer the ‘which is best’ question is to show you the original image and compare it with the two sharpened versions, one using USM and the other a high pass filter.  Here goes.

Original Image – As Shot

Sharpened with Unsharp Mask

Sharpened with High Pass Filter

Six of one and half a dozen of the other?  Yeah, when looking at the images like this it’s pretty damn close.  Is there a color difference under the trunk of the USM version?  Can you see the difference between the two?  After such a lengthy post the actual answer is – it does not really matter!

The only real way to check the sharpness of your images is zoomed in but don’t get carried away.  If you need to zoom in to 200% to see a difference do you really think the people who will be looking at your images on a website or in a book will see a difference?  Also, keep in mind that the final destination of your image will also influence the way in which and how much you sharpen an image.  Is your image only going to go up on a website or are you planning to do some large format canvas prints?  Everything makes a difference!

Whether you choose to use USM, high pass filter or a third party plugin such as Nik Software’s Sharpener Pro 3.0 sharpening is a necessary evil of digital photography.  Whichever sharpening road you choose to take, make sure the destination is a sharp and crisp image that still looks natural. And yes, you can sharpen an image too much!

I tried to stick to the basics as per some of the questions I received but if you have any comments or further questions please done hesitate to comment below!

If you have been following the blog during the last week or so you will recall last Saturday’s post – Africa On Your iPhone.  In this post I uploaded three iPhone wallpapers that you can download for free simply by clicking on the image of your choice. I have also tested these wallpapers on some of the newer  Nokia handsets and it works just fine.  During the week I will be posting another 7, yes 7, free iPhone wallpapers.  In a different post I will also be looking at a number of iPhone applications that you might find handy when you visit Africa for a photographic safari.  Some amazing stuff out there so make sure to check out these and other posts later this week.

Stay sharp!

Gerry