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Edmonton, Alberta
Canada
331 Posts |
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Vancouver, BC
Canada
874 Posts |
Posted - 01/16/2012 : 4:51 PM
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Be careful. The unsharp filter is a photo-editing tool. Too much of it will introduce features where none were present in the original. The unsharp mask is especially bad for skin - it creates pock marks and wrinkles. It also creates un-realistic textures on surfaces like sand or rock. Like most photo editing tools, the numbers mean very little. You need to apply the filter, look at the result, try a bit more or less, and look at it again, etc. Pay special attention to the central object in the photo (especially if it is a face). And always err on the side of caution.
The effects of the unsharp filter are more noticeable on larger images and images with higher resolution. So if you plan to print your pictures, make sure you edit on a large monitor.
The unsharp mask is a common tool in most photo-editors (ex photoshop). It is also built into the hardware of most consumer-grade cameras. It is applied automatically after the photo is taken but before it is written to the card. A "raw" image does not have filters applied.
Unsharp masking works by comparing the image against a blurred version of itself. Any place where the two images are different is assumed to be an edge and is increased in brightness and/or contrast.
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Squamish, British Columbia
Canada
1008 Posts |
Posted - 01/16/2012 : 7:01 PM
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Some tips on general fuzziness in an image.
Sometimes the haze is merely that the temperature is too cold in the image. Adjust the temperature towards a warmer tone.
Fix chromatic aberrations, they can add a lot to the general blurriness of the image. |
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Vancouver, BC
Canada
874 Posts |
Posted - 01/16/2012 : 7:46 PM
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The original picture did not lack sharpness - ie it was in focus. So, the unsharp mask is not the correct tool to use.
But if you look at the histogram, much of the colour space is wasted:
A better tool to use would be levels.
If you adjust your levels to use the full gamut the colours are much richer and there is more contrast, and the picture still looks realistic:
 
You can achieve almost the same effect by choosing "AutoLevels" in your photo editor. Occasionally Autolevels can be tricked by a bright patch of snow or a deep shadow so you may want to adjust by hand some of the time.
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Edited by - weedWhacker on 01/16/2012 7:54 PM |
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Port Moody, BC
Canada
544 Posts |
Posted - 01/16/2012 : 8:12 PM
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quote:
Originally posted by ecoulthard
Check out this example before and after photo I took of Luellan Lake in Banff.
 
I think this one is overdone (too much contrast), and looks unnatural. I'd back off about 25%-40%. This is the problem with hazy photos like this, even if you boost contrast, they will still not look that great, and trying to stretch what you can do with them will most of the time give you these unnatural results. It's actually much better to leave some haze, than try to eliminate it.
Btw, if you have Photoshop, you can use Auto Color (or Auto Contrast) on these, and you can even batch edit all of them if you like. |
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Edmonton, Alberta
Canada
331 Posts |
Posted - 01/17/2012 : 04:28 AM
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quote:
Originally posted by leimrod
Some tips on general fuzziness in an image.
Sometimes the haze is merely that the temperature is too cold in the image. Adjust the temperature towards a warmer tone.
Fix chromatic aberrations, they can add a lot to the general blurriness of the image.
Can you explain some of the terminology you use such as temperature? I am more of a beginner-intermediate when it comes to photo editing. It would also help to point out what tools I could use to accomplish these tasks. Thanks. |
Edited by - ecoulthard on 01/17/2012 04:44 AM |
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Edmonton, Alberta
Canada
331 Posts |
Posted - 01/17/2012 : 04:34 AM
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quote:
Originally posted by weedWhacker
The original picture did not lack sharpness - ie it was in focus. So, the unsharp mask is not the correct tool to use.
But if you look at the histogram, much of the colour space is wasted:
A better tool to use would be levels.
If you adjust your levels to use the full gamut the colours are much richer and there is more contrast, and the picture still looks realistic:
You can achieve almost the same effect by choosing "AutoLevels" in your photo editor. Occasionally Autolevels can be tricked by a bright patch of snow or a deep shadow so you may want to adjust by hand some of the time.
Thanks, but I actually did use auto levels first in the list of steps I mentioned. Good to know that using the unsharp mask may be to much in most situations. I'm not sure that anyone would notice the unsharp mask if I didn't point it out though. When I did this photo I noticed big differences after levels and after the unsharp mask. |
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Edmonton, Alberta
Canada
331 Posts |
Posted - 01/17/2012 : 04:43 AM
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quote:
Originally posted by Arnold
quote:
Originally posted by ecoulthard
Check out this example before and after photo I took of Luellan Lake in Banff.
I think this one is overdone (too much contrast), and looks unnatural. I'd back off about 25%-40%. This is the problem with hazy photos like this, even if you boost contrast, they will still not look that great, and trying to stretch what you can do with them will most of the time give you these unnatural results. It's actually much better to leave some haze, than try to eliminate it.
Btw, if you have Photoshop, you can use Auto Color (or Auto Contrast) on these, and you can even batch edit all of them if you like.
Thanks for the advice. I agree that the photo isn't great in the first place. That is why I don't feel bad editing it so much. I am guessing that Auto Color in Photoshop is the same as auto levels in GIMP, which is the first of the 2 things I did to the photo. With a bunch of hints from the net, I was able to create a script to batch edit all the photos in a directory to apply auto levels and then the unsharp mask to them. If anyone is interested I could post it, but it is very advanced. I think I will stick to GIMP since it is free. |
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 Outdoors addicted flyfishing, skiing, snowshoeing, hiking car crooner and resident motormouth
Da'Wack, BC
Canada
5372 Posts |
Posted - 01/17/2012 : 09:37 AM
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quote:
Originally posted by ecoulthard
quote:
Originally posted by weedWhacker
The original picture did not lack sharpness - ie it was in focus. So, the unsharp mask is not the correct tool to use.
But if you look at the histogram, much of the colour space is wasted:
A better tool to use would be levels.
If you adjust your levels to use the full gamut the colours are much richer and there is more contrast, and the picture still looks realistic:
You can achieve almost the same effect by choosing "AutoLevels" in your photo editor. Occasionally Autolevels can be tricked by a bright patch of snow or a deep shadow so you may want to adjust by hand some of the time.
Thanks, but I actually did use auto levels first in the list of steps I mentioned. Good to know that using the unsharp mask may be to much in most situations. I'm not sure that anyone would notice the unsharp mask if I didn't point it out though. When I did this photo I noticed big differences after levels and after the unsharp mask.
If you were trying to submit to a stock agency for commercial purposes or wanted a large print to the photo you would. For use strictly online in small format you can get away with it for the most part.
Very cool that you wrote a script for batch processing though.
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Edited by - exscape on 01/17/2012 09:40 AM |
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Vancouver, BC
Canada
874 Posts |
Posted - 01/17/2012 : 10:21 AM
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ecoulthard: save your originals. In time you may decide that your batch-processed photos are inadequate. It is very hard to repair a photo that has been incorrectly edited.
If you are working from film scans, save the negatives.
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Edmonton, Alberta
Canada
331 Posts |
Posted - 01/17/2012 : 12:40 PM
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quote:
Originally posted by weedWhacker
ecoulthard: save your originals. In time you may decide that your batch-processed photos are inadequate. It is very hard to repair a photo that has been incorrectly edited.
If you are working from film scans, save the negatives.
Good advice for everyone. I threw away some of my early originals from 2005 that I stitched together to create Panoramas. Then when I found a program that does a much better job I couldn't go back and redo the panoramas. You never know what future advances in photo editing will enable you to do. Fortunately for me, I only threw away the original photos from about 3 panoramas. |
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Satirical photoshop junkie who frolics in the mountains of the Chilliwack River Valley
Chilliwack, BC
Canada
6908 Posts |
Posted - 01/17/2012 : 12:53 PM
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quote:
Can you explain some of the terminology you use such as temperature? I am more of a beginner-intermediate when it comes to photo editing.
The temperature is basically the same as white balance. There's a great tutorial here:
http://www.kenrockwell.com/tech/whitebalance.htm
Image haze can also be caused by not shading the lens properly on a sunny day (one reason lens hoods are so important if you have one). The HDR function also reduces contrast and can make images look dull and flat.
I usually use a cloudy white balance for my in-camera setting (all cameras nowadays have custom white balance settings) for warmer tones unless of course I'm shooting in obvious bright sunlight.
The better photo editors allow you to adjust the white balance (making sure the whites in your photo are truly white) but as already pointed out, you may be introducing other image quality issues by changing a JPEG image too much. I also like to slide my blacks slider a bit for more contrast and more punch. Some editors also have a clarify option that works really well for more punch. |
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Edmonton, Alberta
Canada
331 Posts |
Posted - 01/17/2012 : 1:13 PM
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quote:
Originally posted by BillyGoat
quote:
Can you explain some of the terminology you use such as temperature? I am more of a beginner-intermediate when it comes to photo editing.
The temperature is basically the same as white balance. There's a great tutorial here:
http://www.kenrockwell.com/tech/whitebalance.htm
Image haze can also be caused by not shading the lens properly on a sunny day (one reason lens hoods are so important if you have one). The HDR function also reduces contrast and can make images look dull and flat.
I usually use a cloudy white balance for my in-camera setting (all cameras nowadays have custom white balance settings) for warmer tones unless of course I'm shooting in obvious bright sunlight.
The better photo editors allow you to adjust the white balance (making sure the whites in your photo are truly white) but as already pointed out, you may be introducing other image quality issues by changing a JPEG image too much. I also like to slide my blacks slider a bit for more contrast and more punch. Some editors also have a clarify option that works really well for more punch.
Thanks for the tips BillyGoat. I remember trying "Auto White Balance" in GIMP and getting pretty much the same result as "Auto Levels". I'll have to remember to shade my lens in the future. I have always used a point and shoot camera which is probably a source of a lot of image quality issues. One thing I commonly do is point my camera at the sky and have it auto adjust the exposure and what not for the sky before taking a photo of a mountain. My cameras tend to over expose sometimes for some reason and this seems to fix it. |
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Langley, BC
Canada
1078 Posts |
Posted - 01/17/2012 : 9:10 PM
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quote:
Originally posted by weedWhacker
Unsharp masking works by comparing the image against a blurred version of itself. Any place where the two images are different is assumed to be an edge and is increased in brightness and/or contrast.
It works by subtracting, not comparison. Recall that the impulse response of a high pass filter is just the delta function minus the impulse response of a low pass filter. Blurring the image, with a Gaussian filter is the same as low pass filtering. The end result is that you are just cutting out low frequency information in the image.
The best result is going to involve some combination of un-sharp mask and histogram. |
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Vancouver, BC
Canada
874 Posts |
Posted - 01/17/2012 : 9:25 PM
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Yes, of course you are right. I was being lazy with my grammar.
The point I was trying to make was that unless you understand the effects of the unsharp mask, don't use it. The Levels tool almost always improves an image; unsharp often makes it worse.
Here is a typical example of too much unsharp masking. Note the thumbnails dont look bad, but as soon as you click on the image the un-filtered image looks much better.
 
No amount of unsharp masking would improve the original image (it is a stock photo of Halle Barry, shot by a professional photographer and expertly 'shopped). That is one reason why it may not be a good idea to trust a batch process to edit your photos.
(Edited to remove inappropriate comparison). |
Edited by - weedWhacker on 01/18/2012 5:50 PM |
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canine loving, machete-toting bushwhacking lake seeker, Indiana Jones hat-wearing off-road 4x4 guru
Surrey Hole, BC
Canada
6784 Posts |
Posted - 01/17/2012 : 11:33 PM
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| PROACTIV skin cream.. |
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Hope, BC
Canada
7098 Posts |
Posted - 01/18/2012 : 09:12 AM
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| Interesting discussion, on another note thanks for showing us what Halle Barry will really look like in 15 years (still ugly). That effect almost looks like a makeup removal technique. |
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Vancouver, BC
Canada
874 Posts |
Posted - 01/18/2012 : 09:55 AM
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Making a photograph look worse is easy.
It is the opposite direction that is hard.
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Calgary, Alberta
Canada
617 Posts |
Posted - 01/18/2012 : 11:30 AM
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I agree with most of what people have said here. The best way to make a landscape photo 'pop' is with a technique called 'local contrast enhancement' (http://www.luminous-landscape.com/tutorials/contrast-enhancement.shtml).
Nowadays there are easier ways than photoshop - I use Lightroom and the 'clarity' slider along with 'auto'. Picasa (google) does a good job too.
The best advice I can give is take your shots in RAW format, convert to 'DNG' on import and use a non-destructive editting program like Lightroom so that your originals are never modified. The bonus with a program like Lightroom is the keywording and categorization you can do. When you have 100,000+ photos after a few years, this is really handy. Now I can search for specific mountains or dates and find photos I'm going after. |
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Edmonton, AB
Canada
216 Posts |
Posted - 01/18/2012 : 2:26 PM
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I take all of my photos with a point and shoot as well and, along with the tips above, you should also look into layer masking. It doesn't do anything specifically in itself, but it will allow you to specifically target areas within your photo for adjustments and sharpening [you duplicate your base photo, make your adjustments to that layer, add an opacity mask, and then use a variety of methods - such as using a simple gradient or a paint brush - to blend it back into the original shot].
I find that sharpening is great for distant peaks, but adds too much noise to the foreground. I find that level adjustments are great for bringing blown out skies back, but can quickly destroy shadow detail (by crushing your blacks) in the foreground. Being able to work on those areas separately can help a lot. |
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Satirical photoshop junkie who frolics in the mountains of the Chilliwack River Valley
Chilliwack, BC
Canada
6908 Posts |
Posted - 01/18/2012 : 9:38 PM
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quote:
Nowadays there are easier ways than photoshop - I use Lightroom and the 'clarity' slider
Yes the clarity slider on Lightroom is really nice as is the blacks slider. |
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Make Your Photos Crisp and Clear
