overuse of "unsharp mask" - DPChallenge Forums

08/10/2003 03:30:23 PM · #4

Actually, by using some of the "legal" tools to the extreme (Unsharp Mask is a good example) it is possible to dramatically alter the original photo even achieving the pictorial effect of some "forbidden" filter.

My interpretation of the challenge rules about the "legal" tools is that they should not alter the look and feel of the original shot if not in a very limited way.

I also think that the rules should be stated more clearly about this particular issue because I have the impression that they could be interpreted without any restriction on the allowed tools.

timj351

Olympus Stylus 300 Digital

08/10/2003 03:30:34 PM · #5

ditto. I especially noticed it when I got a better monitor. I've toned down my sharpening and I don't even use the unsharp mask much anymore. Instead I created three Actions of varying intensities made up of a special blend of High Pass filter, Smart Blur and edge sharpening. I now just pick the appropriate action and apply it, it couldn't be easier. This combination keeps the small amount of filmlike softness but adds a certain amount of contrast in the details to make the photo have some snap at normal viewing distances. The beauty of the actions are that they don't enhance the noise like the Unsharp Mask can and they create a more filmlike quality to the image which I really like. Anyway, some people are definitely overusing their sharpening tools when, in fact, there are other better methods to create a more desirable appearance.

T

Blinks

08/10/2003 03:30:36 PM · #6

I agree, but then that also brings up the debate about soft focus. Typically soft focus doesn't do very well around here, so that in turn gives the impression that over sharpened ones will. Personally, I just sharpen or not sharpen until I'm happy with the photo, then agonize all week while it gets judged :)

Eliza

Nikon D80

Sigma 28-300mm f/3.5-6.3 for Nikon

08/10/2003 03:45:51 PM · #7

Hmmm, I see my photo's taking some criticism!
Maybe it's oversharpened, maybe it isn't...
how am I supposed to know unless someone (ie the person who posted the thread) lets me know in a comment?
I'm happy to take constructive criticism!
Personally, I don't think my photo was all that incredible,
and I can't help but feel that it did well because of the post processing I carried out on it (levels, saturation, colour balance, USM).
I think if it had been sharpened less it wouldn't have won.
Whether that means it would have been a better photo though is a whole different matter, we could talk all year about whether competitions are a good idea in an artistic arena.
I'd be interested to know other people's opinions!

Grrr! I thought I was logged in as Bobster Lobster!
It's really a post from BOBSTERLOBSTER everyone!

Message edited by author 2003-08-10 15:46:53.

kiwiness

Canon Canon 1d x Mark II

Canon EF 24-70mm f/2.8L USM

08/10/2003 03:54:54 PM · #8

Originally posted by Eliza:

Grrr! I thought I was logged in as Bobster Lobster!
It's really a post from BOBSTERLOBSTER everyone!

Lol, I've done that before under my wife's user-nick too , happens to the best of us Bob :-)

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

08/10/2003 04:04:55 PM · #9

Originally posted by glimpses:

I have done this before, because I really felt it was an improvement over the photorealistic original..

I completely disagree that we should try and regulate the degree to which someone uses a legal effect; not only would it be an administrative nightmare, it is a form of censoring someone's artistic vision. Not all traditional (film) photographs are printed to be "photorealistic" either.

At the same time, I completely agree that USM is generally over-applied to photos prepared for monitor display.

â�¢ You need to use different USM values for web-sized versus print-sized images, especially for the "diameter" setting. The same setting will have a markedly increased effect when applied to an image spread over 640 pixels, compared to the same image spread over 2000 pixels.

â�¢ I will usually apply the USM with lower settings, and then sometimes apply it multiple times. If you notice the haloing around objects, you have probably over-sharpened.

â�¢ Make sure you view the effect with the display at 100% scale, or monitor interpolation will obscure or accentuate the effect.

â�¢ Sharpening also increases the amount of disk space the image requires. I have saved the same image at 147k and 153k, with the only difference being whether I applied the USM filter once or twice.

Message edited by author 2003-08-10 16:22:54.

timj351

08/10/2003 04:19:23 PM · #10

Bobster Lobster, I think your photo is great and deserving of first place, and while I do think tht it may be slightly oversharpened there are many other photos that take the sharpening much farther and they are the ones I am primarily talking about.

Even though I tend to keep my photos more on the realistic side I completely agree with Paul regarding the use of filters. As long as they are legal then it should be up to the photographer in how they are applied.

T

glimpses

08/10/2003 04:56:49 PM · #11

Originally posted by GeneralE:

I completely disagree that we should try and regulate the degree to which someone uses a legal effect; not only would it be an administrative nightmare, it is a form of censoring someone's artistic vision. Not all traditional (film) photographs are printed to be "photorealistic" either.

I may share this view but then I do not really understand on what basis some tools are defined as "legal" while others are not.

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

08/10/2003 05:08:59 PM · #12

In general, except for sharpening (and blurring, which was added later), filters which change the location of pixels are prohibited, while tools whose primary effect is to change the color of pixels are allowed.

I believe the principal principle (sick)(sic) is to allow tools commonly used in the "home darkroom" (except for dodge/burn and dust-spotting), while prohibiting those which are purely digital manipulations, but have no common analog analogue (I had to WORK to get that one in!).

glimpses

Olympus OM-D E-M1 Mark II

08/10/2003 05:28:03 PM · #13

Thanks for the clear explanation.

Actually, I hope then that all the limitations will be removed one day because I am 100% sure that old wizards of the darkroom would have said that they could have performed any trick that photoshop does. ;)

Chiqui

Olympus 12-40mm f/2.8 Pro

08/10/2003 06:13:43 PM · #14

i have recently noticed the trend around here of everyone using over-sharpened photographs... too much sharpening brings the quality of the image down... and yet everyone seems to like it... a fine example is the dragonfly picture that won the garden challenge... its a great photo, it's just way too sharp...what doo you guys think? maybe im just going crazy...

I don't believe this!!! It seems like one can never win! People complain if a photo is not sharp, AND they complain if it is. Tell me, are people ever at least content with other's photographs. Cut people some slack!

June

Geo_Griffin

Panasonic Lumix FZ45

08/10/2003 06:18:03 PM · #15

If you take away the USM; us lower end Canon users won`t stand a
chance:).

We`ll definitely be getting comments of `out of focus` and it`s `blurred` :-D

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

08/10/2003 06:38:06 PM · #16

Originally posted by chiqui74:

I try to cut people a lot of slack. And if I feel their photo MAY be oversharpened, I try to mention that specifically, while acknowledging that I haven't seen the original, and their treatment may in fact be the best one possible.

I have a bunch of comparative examples posted in this Gallery of Sharpening Samples.

smellyfish1002

Canon EOS-20D

Canon EF 70-200mm f/4.0L USM

08/10/2003 06:49:27 PM · #17

I used to use USM settings of 70%, radius of 1.0, and threshold of 0 for 72 dpi images. I have gradually changed that to 50%, radius of 0.7, and a threshold of 1 for 640 pix images at 72 dpi.

I don't know what I was thinking before...

JD Anderson

A Weaver

Sony DSLR-A100

08/10/2003 06:52:04 PM · #18

Its all Greek to me

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

08/10/2003 07:32:08 PM · #19

Ultimately, what USM does is find areas of contrasting color, and make some of the dark ones a bit darker and some of the lighter ones a bit lighter, to enhance the visibility of the junction and fool the eye into seeing a "sharper" image.

I'm pretty sure these describe the settings in the Photoshop version of the Unsharp Mask filter, but additions/corrections/elaborations are welcome.

Percentage = some arbitrary and mysterious "degree" with which the effect is applied. Think of it somewhat like opacity; the higher the value, the more emphasis placed on the effect. I typically use a setting between 66%-88%, often applying two passes (and comparing one application vs. two).

Diameter = the "width" of the area over which the effect is applied. For low resolution images, values under 1 are common; I use 0.6-0.8.

At low resolutions, an element in the image, such as a rope or branch, may only be 1-3 pixels across. If you tell the sharpening algorithm to affect a 1-pixel area, you cound be affecting the entire element (it's applied from both sides). In a high-resolution print image, that same rope or branch may be represented by 6-8 pixels, so applying an effect to 1.3-1.6 pixels will leave the "interior" part of the original element intact.

Threshhold = how "different" in color two adjacent pixels must be before the sharpening effect is applied. Setting it to axtremely low values (e.g. 1) means that virtually any adjacent pixels will have their contrast enhanced -- not usually a good idea, and one which can lead to banding in what should be a smooth gradient.

For images with smooth tones (flesh tones, skies, flower macros) I usually use a threshhold of 7. For images with small detail (animals, landscapes and leaves) I usually use a setting of 5.

Gordon

RIM BlackBerry Curve

Canon EF 85mm f/1.8 USM

08/10/2003 08:04:49 PM · #20

//www.luminous-landscape.com/tutorials/understanding-series/understanding-usm.shtml

Message edited by author 2003-08-10 20:04:55.

maxpower

Canon EOS-10D

08/10/2003 08:20:14 PM · #21

this may be off-topic, but a good trick for some new photoshop users is to start with auto-levels, then go to edit - fade - 50% and set it to either multiply or screen (whichever looks best) i htink this gives a film-like softness... then after that go in and LIGHTLY sharpen... i know that all sounds random and un-related, but i get the best results doing that...

DennisF

Nikon D100

08/10/2003 08:34:17 PM · #22

Why does the "how" matter? I don't obsess over the amount of USM and if it is "over-sharpened" relative to what I do. I just look at the image. Likewise, if I like the result and its legal, I do it. Some others will also like it and some will not.

It will probably get a "1" anyway for being an 89 degree angle rather than 90 degree.

Vent, vent. Sorry.

Dennis

timj351