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        Discussion Area 討論區 >> Photo Gallery 相片分享 I >>  Common Buzzard
        
(Message started by: KK Hui on Nov 30^th, 2004, 8:32am)

Title: Common Buzzard
Post by KK Hui on Nov 30^th, 2004, 8:32am

http://img.photobucket.com/albums/v22/kkhui/Avian/291104_07x.jpg

MPNR
29/11/04

One of the shots taken yesterday was this Common Buzzard ... ::)

My thanks to Mike Kilburn for the id!

EOS-1D Mk II, EF600/4L + EF1.4x
Evaluative @ + 2/3, ISO 200

KK Hui ARPS
www.geocities.com/kkhui_001

Title: Re: Common Buzzard
Post by Anguslau on Dec 1^st, 2004, 6:41pm

Great photo as usual! ;D ;)
The feather details are unbelievable, tack sharp. Love the color of the sky too - not too blue, just right for my taste! ;D

Title: Re: Common Buzzard
Post by KK Hui on Dec 2^nd, 2004, 9:42am

Thanks for your kind word, Angus!
Have not seen any of your work lately, what's up?! ;D

Best and Good Shooting!

KK Hui ARPS
www.geocities.com/kkhui_001

Title: Re: Common Buzzard
Post by Anguslau on Dec 2^nd, 2004, 10:04am

Due to personal reasons, haven't been shooting over the last couple of weeks. Hope I can resume next week, and see you in the field... ;)

Title: Re: Common Buzzard
Post by Daniel CK Chan on Dec 3^rd, 2004, 1:24pm

A great shot, KK! Seems to be a bit blacklighting, right? since I can see some white blue around the body of the bird ???

Title: Re: Common Buzzard
Post by Etta on Dec 3^rd, 2004, 1:43pm

Agree, same question as Daniel, and I wonder whether it's the 'Aura' （體光）of the bird. :D :D

Etta

Title: Re: Common Buzzard
Post by Webcreeper on Dec 3^rd, 2004, 8:59pm

I think that it is an optical illusion. Put your finger or anything dark against any part of the blue background and you will see the same effect.

;)

Title: Re: Common Buzzard
Post by bfspoonbill on Dec 4^th, 2004, 12:39am

The differences in colour and intensity described by you all are obvious on my cheap cheap Topcon LCD monitor screen and Philips CRT monitor.

As what I commented on 20/11 (KK's imperial eagle) and 25/11 (Owen's kingfisher) in this board, I think.

As said, photos of some others (such as pip.., hand.., dan...) do not have these phenomena.

Title: Re: Common Buzzard
Post by KK Hui on Dec 4^th, 2004, 7:33am

Thank you all for your input ...

To be honest, I do not see a problem with uneven background color/intensity or halo around the subject here. Neither I've heard any complaint on the issue from other photographic forums I posted. I'm using a CRT mon for my photo editing works by the way ... ;D

KK Hui ARPS
www.geocities,com/kkhui_001

Title: Re: Common Buzzard
Post by Daniel CK Chan on Dec 4^th, 2004, 10:36am

on 12/04/04 at 07:33:54, KK Hui wrote:

KK,

Forget to tell that I did see this in my office IBM 17" CRT monitor. I have not opened my home PC/LCD for 2 weeks at least. ;D

Regards
Daniel

Title: Re: Common Buzzard
Post by Anguslau on Dec 5^th, 2004, 12:16pm

I believe the apparent halo is mostly optical illusion due to signal processing by our eyes/brain. They often do amazing things that we did not realise...

Just to "proof" the point, I downloaded kk's image and cut out the eagle, leaving only the blue sky with a white "eagle". From what I can see, the halo is largely gone. There may still be a very slight hint of a "halo", which could be the result of sharpening or local contrast enhancements...
http://www.pbase.com/anguslau/image/37121815.jpg

Title: Re: Common Buzzard
Post by KK Hui on Dec 5^th, 2004, 12:45pm

Thanks Angus for the effort!

Having done a minute examination on my post-processing workflow on this image, I found the root cause ... And here is the re-post of the same but with a slightly bigger image size.

http://img.photobucket.com/albums/v22/kkhui/Avian/291104_07xl.jpg

The halo or uneven brightness around the subject has now gone for good. The artifact was in fact caused by the use of Highlight/Shadow tools in PScs to 'correct' some extreme contrasty areas.

Hope you see the difference and for the better too ... ;D

KK Hui ARPS
www.geocities.com/kkhui_001

Title: Re: Common Buzzard
Post by Webcreeper on Dec 6^th, 2004, 3:22am

The illusion is due to Subjective Brightness - colors may change appearance based on the colors surrounding.

Here's a LABORATORY (http://lite.bu.edu/vision/applets/Lightness/BrightnessEffect/BrightnessEffect.html) for you to experiment with the various effects.

To simulate the conditions of the buzzard photo:

1. Resize the new window so that you can read these instructions as you go.

2. Set the control sliders for all three elements (2 circles and the background) to the following settings

Hue = 195
Saturation = 70
Brightness = 255

The result should be a pure skyblue background.

3. Decrease the setting of the middle Brightness slider from 255 to 0 - see the halo appearing gradually around the circles.

You may like to experiement with other combinations.

More optical illusions from Project Lite (http://lite.bu.edu/vision/applets/lite/lite/lite.html)

Have fun! ;D

Title: Re: Common Buzzard
Post by bjingbar on Dec 6^th, 2004, 4:57am

On my Apple 23" HD Cinema Display the shot looks fantastic

Great work KK

Title: Re: Common Buzzard
Post by Betty on Dec 6^th, 2004, 8:22am

I can see the difference of the repost, the halo is gone.:D
I find the halo is a kind of sight illusion. If I keep looking at the repost for a longer period and keep thinking if there is light around the body, the illusion though not so obvious will come up to my eyes once again.

Title: Re: Common Buzzard
Post by KK Hui on Dec 6^th, 2004, 8:41am

on 12/06/04 at 04:57:57, bjingbar wrote:

On my Apple 23" HD Cinema Display the shot looks fantastic

Great work KK

Now that's an endorsement, Bob! ;)
I gether you meant the re-post, right?!

KK Hui ARPS
www.geocities.com/kkhui_001

Title: Re: Common Buzzard
Post by Etta on Dec 6^th, 2004, 12:10pm

What an interesting learning! Thanks KK and everyone!

Etta :D