Part Five: The Final image: Sharpening

Well I have arrived at the final part of this course and this time its all about the finishing:  I need to look at sharpening to begin with, and having read the information on sharpening and why we do it in The Digital SLR Handbook by Michael Freeman (further details are in my reading list) I feel I am read to start.

When I started reading I found it interesting that it can be better to 'un sharpen' than to 'sharpen', this goes back to film days. Sharpening is a subjective impression and how much a photograph is sharpened can depend on the person doing the sharpening and personal preference. This should also be the last action you perform on an image before it is printed, used digitally etc. There are three standard settings used in the un sharpen process, radius: the distance around the pixels to calculate the sharpening process, the amount: it is not unusual for this to be between 150 and 200% and finally the threshold: This is used to prevent sharpening where the difference between pixel values is small.

I need to use an image that has been processed as a standard reference, but there must be no sharpening applied to this one.  I then need to make a further three versions applying more sharpening each time, the strongest should be noticeably sharper.
I had just done a photo shoot with a rockabilly model and thought that the photograph would work well for this exercise.
Below is the original photograph and then the following three show various degrees of sharpening, this might not be as obvious on the smaller size photographs displayed on here so I will write about my findings in more detail below.

 I took the first photograph and looking at it on my desk next to the computer screen with the on screen image at 100% and started to look for details, the first thing I noticed was there was little definition to the shape of the lips this was particularly noticeable when viewed through the magnifying glass or on screen at 100% , I must admit I was quite surprised by this.

On photograph one I just altered the levels slightly but other than that I didn't do any other alterations.
For the following three photographs I used the same method but in varying degrees,

Photograph two I used the un sharp mask and adjusted the amount to 58%, the radius to 1.4 pixels and the threshold amount to 14.
Having made just small adjustments I thought it would be interesting to see if there was any difference to the prints in particular. This time I could start to see a bit of definition coming to the eyes and lips this is also  noticeable on the models eyeliner.

Photograph three and this time I applied a bit more sharpening, again I used the un sharp mask and adjusted the amount to 76% the radius to 2.0 pixels and the threshold to 30 levels. This time there is quite a noticeable difference between the unsharpened photograph and this one, I looked closely not only at the eyes and lips but I could also see how fine lines and the creases around her nose start to be more pronounced in this photograph, this didn't look so bad on the printed one. By now I am really interested to see the results of the final amount of sharpening has done.

Photograph four and the adjustments are as follows: amount 118% the radius 5 pixels and the threshold 81 levels, now you can really see the difference between the unsharpened image and this one. There is a real sharpness to the final image its almost hard in places and really shows up any fine lines or creases to the skin. This didn't seem to be noticeable on the on screen image which surprised me and I kept going backwards and forwards to be sure, as this is different from the results on photograph three.

I now have to chose which amount of sharpening I prefer, I discounted images one and two almost immediately as neither of these showed the shapes of my models features, and as she is partly Malaysian I considered it important to show that off particularly in the shape of her eyes. I also think the amount of sharpening depends on how large and image you require as the final product.
 Images three and four are left and I must admit it has been difficult to decided between the two of them, although I think image four is slightly over sharpened, I almost prefer the shape of her lips, but the eyes are too hard, however if I was having this as a large print this would be the one I would go with.  I have decided to walk away from the images for a few minutes and then view them again with fresh eyes. I ended up walking away for nearly an hour and having viewed the two photographs again I have finally decided on photograph three, I think overall this has just the right amount of sharpening, her features are clear but not harsh there is still some softness to her face and is more true to life.



I have been reading back over my notes and decided to try amount 200%  radius 2 pixels and 68 threshold but this was much too harsh on her features.

Sharpening isn't something that I have done a lot of previously but I can now see how the correct amount of it can make a difference to a photography and I will make it the final step when processing images in future.