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        Discussion Area 討論區 >> Photo Gallery 相片分享 I >>  Northern Shoveler
        
(Message started by: Anguslau on Nov 5^th, 2005, 11:16am)

Title: Northern Shoveler
Post by Anguslau on Nov 5^th, 2005, 11:16am

Its duck time again at NSW! :D Weather is perfect too. Very nice place to be this time of the year. But the place is getting very popular and sometimes noisy even on weekdays.

NSW 3/11/2005
1D Mark II, EF600, f/4, 1/5000s, iso320
http://www.hkbws.org.hk/fileServer/PhotoG/anguslau/anguslau_111.jpg
http://www.pbase.com/anguslau/image/51782720.jpg

Title: Re: Northern Shoveler
Post by anonymous_guy2 on Nov 5^th, 2005, 1:27pm

Wonderfully clear shot - can you send some (the birds) over to Lamma......., please

Title: Re: Northern Shoveler
Post by KK Hui on Nov 5^th, 2005, 1:29pm

Good job getting the eye thro the wing, Angus!
BTW the sharpening halo seems excessive this time ... ;)

Would go early and avoid weekends for the crowd. Nothing much we can do other than that unfortunately. :(

KK Hui FRPS
www.geocities.com/kkhui_001

Title: Re: Northern Shoveler
Post by Anguslau on Nov 5^th, 2005, 4:45pm

Thanks for the comments! :)

kk, I am being haunted by these sharpening halos. :( Hope you can give me a hand here. I can see the halo very clearly, particularly below the dark belly of the bird. I tried reprocessing the image again. But can even see the halo without sharpening. I think I am doing something wrong here. Would you mind take a look at my work flow and see what I have done wrong? :-[ BTW, also tried converting using the PS ARC for comparison, same halo problem. :(

Here is a link to a tighter crop of the image which I have done the following:
1. Converted from raw to 16-bit TIFF using Capture One Pro: Increased EV by 0.15, disabled sharpening, enabled chroma noise reduction, luminance noise reduction off
2. Loaded TIFF into PS, cropped image
3. noise reduction using NeatImage, no sharpening
4. increased contrast using curve
5. increased saturation very slightly using channel mixer
6. saved as JPG at maximum quality and uploaded to pbase. Image link: http://www.pbase.com/anguslau/image/51793671/original.jpg

What I usually do for a normally sharp image (like this one) after all other processing is apply sharpening using USM in PS: amount=300, radius=0.3, threshold=0. This will give me a sharp image when viewed on screen at 100% without excessive artifacts. I may try other sharpening methods if this doesn't work well. I then save the image as JPG at maximum quality to become my "master" processed image (I do not save TIFF files to save disk space).

For web posting, I do the following:
1. load the "master" JPG file into PS
2. add border, image fit to 650x650: bicubic sharper
3. apply USM: amount=100, radius=0.2, threshold=0
4. apply USM again: amount=100, radius=0.2, threshold=0
5. convert to 8 bit, convert color profile to sRGB
6. save as JPG, quality=8
7. upload JPG to pbase

I believe the sharpening halo still looks reasonable on my "master" JPG (after sharpening). But during the conversion for web posting, the halo becomes excessive. ??? Would that be your take as well? Any suggestions you can give to me to cure or alleviate this problem? Thanks!

Title: Re: Northern Shoveler
Post by KK Hui on Nov 5^th, 2005, 5:17pm

Angus,

The workflow looks good as is. Now I took your 'original.jpg' and process it in PS CS2 and result is as shown; no halo!

I first resize it to at 72 ppi. Then selective sharpened the subject using usm with 300/0.2/0. Deselect and finish off by overall sharpening using usm with 200/0.2/0 this time. That's it! However I havn't applied any noise reduction filter, saturation or contrast in this one.

Amount of sharpening would very much depend on the quality and size of the image to start with ...

http://img.photobucket.com/albums/v22/kkhui/original.jpg

See what you think!

KK Hui FRPS
www.geocities.com/kkhui_001

Title: Re: Northern Shoveler
Post by Bob Thompson on Nov 5^th, 2005, 5:43pm

KK,

Maybe the society could organise another hands on lecture in processing of digital pictures.

One part of photography is capturing the shots (which a lot of members are doing very well) but it is in the processing side, where we all need help.

As can be seen above, you were able to make Angus's good shot into an even better shot.

Hope to see you all at NSW next week

Bob

Title: Re: Northern Shoveler
Post by Anguslau on Nov 5^th, 2005, 9:45pm

kk, thanks very much for the demonstration. I think I finally figured out the cause of the problem! :D Hope this will be useful for others too.

After trying out all sorts of combinations, I found that there are two problem steps in my workflow:
1. sharpen the "master" JPG before resizing
2. resizing using bicubic sharpen

I found that if either of the above were present, there will be sharpening halos. To minimise sharpening halos, I need to apply the following workflow:
1. do all other processing such as cropping, color, contrast etc
2. resize for web using bicubic smooth
3. select the subject (feather or not doesn't make much difference)
4. usm 500 0.2 0
5. usm 100 0.2 0
6. usm 100 0.2 0 (may be more or less depending on image)
7. deselect subject
8. usm 200 0.2 0
9. convert to sRGB and save for web

Here is my final output, halo is very subdue!
http://www.pbase.com/anguslau/image/51799066.jpg

kk, the version you got was still in Adobe RGB, hence color looked a bit off. To bring justice, below is the one converted to sRGB to bring back the color:
http://www.pbase.com/anguslau/image/51799065.jpg

Title: Re: Northern Shoveler
Post by KK Hui on Nov 6^th, 2005, 8:20am

Angus,

Oops! I didn't even check for color profile in my last repost. Thanks anyway!

I'd say you solved your problem ...
Always do the post editing after crop and resize. Leave the sharpening as your last step then add frame/border and signature if you like. In resizing I find it's best to use the normal 'Bicubic'.

Best and Good Shooting!

KK Hui FRPS
www.geocities.com/kkhui_001