Very little can be done to sharpen a blurred image when it’s being taken of something 100 times larger than life. Every tiny detail becomes apparent and you need to be doing your utmost to get a clear, crisp macro photograph of the subject at the time of pressing the shutter.
There are however some tips that can make the macro photograph just a little sharper.
For one, because of the shallow depth of field in Macro Photography, many areas of your picture are out of focus already. You can sacrifice these areas of the macro photograph in search of one clear point.
Create a duplicate layer of your image in Photoshop and look carefully at the sharpest point in your picture. (Hoping that this point is on something worthwhile and can become the new focus point. If you’re lucky, the focus falls on a key area like an insect’s eye or the tip of a sword’s blade.)
Now go to your Filters menu, mouseover Sharpen and select Unsharp Mask. Adjust the Amount, Radius and Threshold sliders carefully until you reach the point when the area you have chosen to be the focus point is as sharp as it can be without pixelating. Forget about the rest of the image for now, even if it looks completely pixelated or botched. We will be discarding this, remember.
Now select your Eraser, make sure you have a big soft brush and erase all areas around this point. Your original bottom layer will now be visible. You can now select the bottom layer and, from your filter menu, Blur the bottom layer.
You have effectively faked a shallower depth of field scenario and hidden the flawed or out of focus area of the macro photograph by forcing it to blur just the right amount. Your sharp area still visible will stand out beautifully and your picture will look great. Just be gentle with the sliders in both the sharpen and the blur steps to not over adjust the picture and make it look completely fake.
Another sneaky way to increase focus is to take a picture originally shot at 10 megapixel and bring the size down to say 800 pixels wide. On most computer screens your image will look perfectly in focus. Of course, this works for print as well but your picture unfortunately might need to be postcard size rather than poster size.
As is the case with any photography, the rules and guidelines for a better picture are often shattered for creative effect but assuming you want to simply have a better looking macro photograph with respect to colour and tones, the following steps will assist you along the way. These steps are not necessarily the perfect way, they are the easiest and fastest ways I have found to make these adjustments.
In Photoshop, I like to always first copy my entire image onto a second layer, any adjustments can then easily be removed in specific areas exposing the original.
Once you have done this, press Control L and select either the highlight or shadow eye dropper icon on the bottom right of the levels window. Choose the one depending on whether you would like to increase the overall brightness or darken the image. Then select either the darkest point of the picture with the shadow eye dropper or select the brightest part of the picture with the highlight eyedropper. Your macro photograph will now adjust to make that exact point perfect black or perfect white depending on your choice.
Often this adjustment is too harsh but your next step will compensate for this. By simply typing a number into your number pad, you can adjust the opacity of the top layer bringing into view the original. Play with different percentages to find the best looking combination of the original and newly adjusted layer. The adjusted layer effectively acts as a White balance (or Black balance) adjuster but in the case of Macro Photography, I seldom find that perfect white balance looks better than when I play around with the variations in between. When you are satisfied, you can now press Control E to merge the two layers.
Ok, so with your highlights and shadows set, you can begin playing with colours. Almost always a slight increase in colour saturation results in a better looking macro photograph. This is of course dependant on the image itself and you can see how rich you need to go.