Task: Take an image and process as a reference standard. Make 3 more versions of the image, each with a different degree of sharpening. Compare the 4 images and comment on preferences.
For this exercise I will be using Photoshop Unsharp Mask to explore the effects of sharpening. The course notes suggest using an image that has both edge detail and smoother areas, therefore I chose the image below of 4 parrots sitting on a perch, with detail in the feather areas and smoother around the beaks.
The course notes make a point of viewing the images at 100% magnification. This is something I rarely do and recognise that viewing my images so closely should be part of my workflow. Sometimes it is easy to take it for granted that digital images appear ‘good enough’ when viewed fully onscreen.
Zooming into the original shows the image below.
The unsharp mask tool has 3 values, Amount, Radius and Threshold, which define the strength, the distance it works across the pixels and protection of smoother areas.
1. Increasing the amount, radius and threshold slightly is still very similar to the original image.
2.Increasing the threshold and radius has smoothed the feathers and beak area. This is something I wasn’t expecting to happen. I thought all changes would contribute to sharpening the image. I should maybe have used the radius and threshold less.
3. Pushing the amount up to the very limit of 448% has created fringing around the edges of the parrot outline and blocked the white parts of it’s beak. The feathers have become over-exaggerated and over-saturated.
I preferred the first image because there was enough detail, however this is probably because for the second image I increased the threshold too high. The procedure is very much a pay-off between smoothness of image and clarity of detail. The exercise has certainly made me think more about looking at images in closer detail when enhancing them.