Posted by Ken Atkinson on December 17, 2007 at 10:36 AM
What criteria do you use to decide if an image is acceptably sharp? Before I do any PP, I like to view my Raw images at 100% and decide which are worth keeping and which need to be trashed because they are too soft. I believe I once read in one of George Lepp’s columns that all images will look “somewhat” soft when viewed at 100%.
Dona Hilkey recently posted an image of a Bobcat which many thought was really nice, including me. But there was some discussion about it being soft. Vincent commented about judging the sharpness of an image by viewing it at 100% or 200%. I work with a couple of Canon’s L lenses, regularly use a tripod, cable release, mirror lockup when needed, etc., but don’t ever recall a Raw image being razor sharp at 100% (maybe I am doing something wrong). Yet when I view the image on the monitor at “fit to screen” or “print view”, it looks pretty good.
Maybe with some images, the perception of sharpness will be influenced by the amount of contrast between adjacent colors. This may have been the case with Donna’s bobcat image with a midtone against a midtone. In other cases sharpness may be influenced by the direction or quality of the lighting or the texture of the main subject.
Bottom line, if you view any image at “fit to screen” or “print view” and it looks good, is that an acceptably sharp image or should you make the decision at 100%? I would be interested to hear what many of you have to say about how you judge the sharpness of your work.
Posted by Kent Staubus on December 17, 2007 at 10:51 AM
To throw in yet another variable, how sharp are your eyes when you are trying to judge the sharpness of the image?
It's purely a subjective measure. Most folks take the sharpening as far as they can without developing halos or other obvious signs of sharpening. It's so subjective however, that we generally leave it up to the client, except in cases where we are producing the final product itself, as in a print. Not sharpening for clients allows them to do any further adjustments (including resizing) before sharpening as a final step, always a good idea. In fact, the lab we use for print making for our studio asks that we not sharpen at all, instead leaving it up to them and their methods. So far, I've found no reason to argue with them.
Everything equal, all raw digital images are softer than their film counterparts. Digital sensors have a defined pattern which can cause haring- bone effects with closely spaced parallel lines. That effect is reduced or eliminated by using an "anti-aliasing" mask in front of the sensor which blurs the image. So, the image must be sharpened.
Now, one is faced with the dilemma of first resizing an image followed by sharpening or adjusting the other parameters and then discovering that the image was really soft. My recommendation is to first resize and then attempt to sharpen. If a critical element, such as the eyes, cannot be made sharp without causing artifacts, then the image was too soft to begin with. After a while, one will learn which images can be discarded without attempting to pre-sharpen them. Of course, after the resize and sharpening to determine the quality, the sharpened image can be un-done so that all of the other adjustments are made to the original raw image.
Posted by Dan Borzynski on December 17, 2007 at 12:35 PM
This is one of these very nebulous areas that can be very tough to define verbally. Usually, the key is to how it looks in print, since that is how most photos are viewed by the greatest number of viewer. Echoing a comment on a not-so-appropriate topic, I don't know what sharp is, but I know it when I see it.
Judging sharpness at 100% is tough, since realistically, no digital file really is sharp at that much of a magnification. Even film images have softness coming from both grain and the scanning process.
With regards to the cited image, you do have to keep in mind a couple of things. You are seeing a greatly reduced version of the image. Detail is going to be lost. It is also a jpeg, which is never a good thing to do to a photo, but a necessity for a forum like this. A lack of contrast can be seen as a lack of sharpness, since our brains can be fooled into thinking something is or is not sharp due to presence or lack of sharpness. And last, while I have not looked at the specific image, it certainly is possible it was not sharp.
Which brings me to my final point. It takes a while to develop a feel as to whether an image really is sharp simply by looking at the digital file. The obvious cases, especially when you have serious OOF issues, are pretty straight forward, but there is always that middle ground where it may be okay or maybe not, or maybe only good to 8x10. This is really an experience issue that you'll pick up in time. I have gone back to some older work that I thought was good enough to send out as stock and realized (much to my disappointment) that it really wasn't as sharp as it should have been, or not sharp when it needed to be. Sigh... We all start somewhere.
Posted by Frank Winters on December 17, 2007 at 1:53 PM
Henri Cartier-Bresson questioned as follows (paraphrasing -- I can't find the precise quote): "What is this obsession with sharpness; is it a fetish?"
I'm no expert nor is my technique professional but I'll offer this: if an image looks sharp to the eye when viewed from a comfortable distance and is pleasing, or exciting or beautiful or all three then it is good. If you feel a need to improve it then by all means view it at 100%, but don't expect to see beauty, to be excited, or in most cases even to be pleased.
Dan makes very good points, here; to all of which I agree. The web is notoriously bad for evaluating the sharpness, or lack of it, for a particular image. Also, an image that may appear to be over-sharpened in a web presentation, may not be sharp enough for a fine print. When I comment on images here at NPN, I generally do not comment upon sharpness. I will, however, ask if out-of-focus areas are intentional if they don't look good to me.
Sharpness is truly is a very subjective thing.
-PB
Posted by Bertl Menegoni on December 17, 2007 at 4:46 PM
Hi Ken, why do posts, depending to sharpness all the time have most replies and attention?
Watch pics in the net, watch prints in all kind of magazines. At the same time you must ask:
How saturated is saturated enough? For me this is a learning process, I think we all have to go through it. At the beginning we sharpen and saturate like mad. We have the power! Sharping I find is no more so the theme at the moment but we live in a oversaturated pictureworld. I am in the same situation like you. I must strongly control myself.
Have a good time, Bertl M.
Ken
Below is the address of one of my favorite articles on the topic. I hope you get a chance to read it.
Rick T
http://www.luminous-landscape.com/tutorials/sharpness.shtml
Discussion
8 repliesDona Hilkey recently posted an image of a Bobcat which many thought was really nice, including me. But there was some discussion about it being soft. Vincent commented about judging the sharpness of an image by viewing it at 100% or 200%. I work with a couple of Canon’s L lenses, regularly use a tripod, cable release, mirror lockup when needed, etc., but don’t ever recall a Raw image being razor sharp at 100% (maybe I am doing something wrong). Yet when I view the image on the monitor at “fit to screen” or “print view”, it looks pretty good.
Maybe with some images, the perception of sharpness will be influenced by the amount of contrast between adjacent colors. This may have been the case with Donna’s bobcat image with a midtone against a midtone. In other cases sharpness may be influenced by the direction or quality of the lighting or the texture of the main subject.
Bottom line, if you view any image at “fit to screen” or “print view” and it looks good, is that an acceptably sharp image or should you make the decision at 100%? I would be interested to hear what many of you have to say about how you judge the sharpness of your work.
Kent in SD
Now, one is faced with the dilemma of first resizing an image followed by sharpening or adjusting the other parameters and then discovering that the image was really soft. My recommendation is to first resize and then attempt to sharpen. If a critical element, such as the eyes, cannot be made sharp without causing artifacts, then the image was too soft to begin with. After a while, one will learn which images can be discarded without attempting to pre-sharpen them. Of course, after the resize and sharpening to determine the quality, the sharpened image can be un-done so that all of the other adjustments are made to the original raw image.
Judging sharpness at 100% is tough, since realistically, no digital file really is sharp at that much of a magnification. Even film images have softness coming from both grain and the scanning process.
With regards to the cited image, you do have to keep in mind a couple of things. You are seeing a greatly reduced version of the image. Detail is going to be lost. It is also a jpeg, which is never a good thing to do to a photo, but a necessity for a forum like this. A lack of contrast can be seen as a lack of sharpness, since our brains can be fooled into thinking something is or is not sharp due to presence or lack of sharpness. And last, while I have not looked at the specific image, it certainly is possible it was not sharp.
Which brings me to my final point. It takes a while to develop a feel as to whether an image really is sharp simply by looking at the digital file. The obvious cases, especially when you have serious OOF issues, are pretty straight forward, but there is always that middle ground where it may be okay or maybe not, or maybe only good to 8x10. This is really an experience issue that you'll pick up in time. I have gone back to some older work that I thought was good enough to send out as stock and realized (much to my disappointment) that it really wasn't as sharp as it should have been, or not sharp when it needed to be. Sigh... We all start somewhere.
I'm no expert nor is my technique professional but I'll offer this: if an image looks sharp to the eye when viewed from a comfortable distance and is pleasing, or exciting or beautiful or all three then it is good. If you feel a need to improve it then by all means view it at 100%, but don't expect to see beauty, to be excited, or in most cases even to be pleased.
Dan makes very good points, here; to all of which I agree. The web is notoriously bad for evaluating the sharpness, or lack of it, for a particular image. Also, an image that may appear to be over-sharpened in a web presentation, may not be sharp enough for a fine print. When I comment on images here at NPN, I generally do not comment upon sharpness. I will, however, ask if out-of-focus areas are intentional if they don't look good to me.
Sharpness is truly is a very subjective thing.
-PB
Watch pics in the net, watch prints in all kind of magazines. At the same time you must ask:
How saturated is saturated enough? For me this is a learning process, I think we all have to go through it. At the beginning we sharpen and saturate like mad. We have the power! Sharping I find is no more so the theme at the moment but we live in a oversaturated pictureworld. I am in the same situation like you. I must strongly control myself.
Have a good time, Bertl M.
Below is the address of one of my favorite articles on the topic. I hope you get a chance to read it.
Rick T
http://www.luminous-landscape.com/tutorials/sharpness.shtml