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Thread: PS colour correction

  1. #1
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    Default PS colour correction

    Hi,

    Recently went to San Francisco with my family. Managed to take the following picture of the Golden Gate Bridge, but the air wasn't very clear, and the camera's WB gave a blue cast. So, I gave it a try to salvage the picture in PS. The outcome may not necessary resemble what I actually saw (which was hazy as well). Would like to get feedback on the PS work.

    What I did was to apply Auto-Levels, then tweaked the curves of the individual channels to enhance the contrast and bring out the red in the bridge. Unfortunately it also resulted in a slight red cast on the rest of the picture. Please let me know if the outcome still works for you.

    Thanks!

    Roy

    Original:


    Tweaked:
    As complexity rises, precise statements lose meaning and meaningful statements lose precision.

  2. #2

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    i think the bridge is too red. if i remember correctly, the colour is more like rusty red (reddish-brown) then just plain red. But i not PS expert so can't comment on how to get the rusty red colour.
    cheers!

    btw, which part of seattle you stay? seattle itself or some neighbouring town. i lurv seattle. can post some pics of seattle? e.g. Pikes place, space needle, Puget sound...

  3. #3
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    It seems that the haze reduced the contrast and saturation of your orginal shot. Typical california sky on a sunny day has eye-pleasing saturated navy blue. Maybe u should go back and shoot again

    I tried to adjust but not nice

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    ClubSNAP Admin Darren's Avatar
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    Give it a try - how do u like this?



    1. Reverse USM to remove haze - amount 20-30%; radius 10-20; threshold 0
    2. Select Blue Sky portions; invert
    3. Use Levels to adjust the non-sky portions, bringing in the red, blue, green right sliders slightly (mids and lows untouched)
    4. Flatten layers
    5. Normal USM at 500%; R 0.2; T 2

    voila!

  5. #5

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    Nice and natural looking.

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    When I first posted, the corrected picture looked OK to me. Now, it looked over-saturated.

    Darren's version is natural, but I still feel that there is a liitle too much blue. Maybe I am more sensitive to blue and less sensitive to red. Remember the case when I adjucted the colour of tomshen picture taken a confernece? I thought the skin tones were OK but many felt that it was too red. Maybe it is the lighting in my room.

    Anyway, Darren, what is reverse USM? Is it a PS7 only feature? Is there anyway to acheive the same effect using PS 5 LE (free one lah...)?

    Seems like the only way to retain the blue in the sky while "de-hazing" the bridge is to process the sky and the rest of the picture separately. Looks like a selection nightmare (at least on PS LE), but I will give it a try.

    To beachbum, I am staying in Redmond, a city/town about 30 km east of Seattle. I have posted quite a number of pictures of Seattle before. If you do a search for my posts, you should be able to retrieve most of them. Some of the picuture links may have been broken, if they were hosted on Clubphoto, but the ones on Clubsnap should all be in tact.

    - Roy
    As complexity rises, precise statements lose meaning and meaningful statements lose precision.

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    How about this? Simply do Image -> Auto Contrast, Image -> Auto Colour.



    Regards
    CK

  8. #8
    ClubSNAP Admin Darren's Avatar
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    Originally posted by roygoh
    Anyway, Darren, what is reverse USM? Is it a PS7 only feature? Is there anyway to acheive the same effect using PS 5 LE (free one lah...)?
    This is just using the USM function but with a small amount and a large radius (as compared to a large amount and a small radius for normal sharpening).

    Got the tip from somewhere on the web, but the link is not working now.

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    Thanks, Darren. I will try out to know the effect better.

    ckiang, you version has natural colours for the bridge, but I can see badning in the sky. That is probably due to the jpeg compression. Thanks!
    As complexity rises, precise statements lose meaning and meaningful statements lose precision.

  10. #10

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    Originally posted by roygoh

    To beachbum, I am staying in Redmond, a city/town about 30 km east of Seattle. I have posted quite a number of pictures of Seattle before. If you do a search for my posts, you should be able to retrieve most of them. Some of the picuture links may have been broken, if they were hosted on Clubphoto, but the ones on Clubsnap should all be in tact.

    - Roy
    hi roy, your reply is appreciated! yep i did a search and saw your wonderful shots of mt rainer and pikes place! sure brings back memories!
    btw, don't tell you you are working with M****soft?

  11. #11
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    Originally posted by roygoh
    Thanks, Darren. I will try out to know the effect better.

    ckiang, you version has natural colours for the bridge, but I can see badning in the sky. That is probably due to the jpeg compression. Thanks!
    If you have PS7, you can try the 2 steps on your original and see how it works for you. Auto Color can do amazing things.

    Regards
    CK

  12. #12
    Moralis
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    Hiya! I'm learning my way around Photoshop 7.0 and would like to try my hand at the pic.

    Things I did:

    1. Added a gradient layer effect to the sky attempting to simulate a polarising effect.

    2. Applied USM to the bridge only.

    3. Dodged the highlights of the water below the bridge.

    4. Removed that little boat on the left of the pic.

    5. Tweaked the colour balance of the photo to reduce the bluish cast.

    Here's the result of my experiment:


  13. #13
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    Originally posted by beachbum


    hi roy, your reply is appreciated! yep i did a search and saw your wonderful shots of mt rainer and pikes place! sure brings back memories!
    btw, don't tell you you are working with M****soft?
    Thanks for your compliments.

    When did you visited Seattle? Or did you stay here for a while?

    OK, I will not tell you that I am working with M****soft....
    As complexity rises, precise statements lose meaning and meaningful statements lose precision.

  14. #14
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    Originally posted by Moralis
    Hiya! I'm learning my way around Photoshop 7.0 and would like to try my hand at the pic.

    Things I did:

    1. Added a gradient layer effect to the sky attempting to simulate a polarising effect.

    2. Applied USM to the bridge only.

    3. Dodged the highlights of the water below the bridge.

    4. Removed that little boat on the left of the pic.

    5. Tweaked the colour balance of the photo to reduce the bluish cast.

    Here's the result of my experiment:

    Hi Moralis,

    Thanks for your interest!

    I am travelling right now, and can only view the pictures on the LCD screen on my laptop, which does not have very good colours. I will look at it again 1.5 weeks from now after I return to home.

    From my LCD screen, I did find the halo effect around the main cables of the bridge quite obvious. What is the radius setting in USM that you have used?

    - Roy
    As complexity rises, precise statements lose meaning and meaningful statements lose precision.

  15. #15
    Moralis
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    I used a radius of about 4 pixels. I think the halo effect may also be due to my inaccurate selection of the bridge cables.

    But there isn't much contrast between the cable and the sky when zoomed in, they tend to dissolve into one another, making selection difficult.

  16. #16

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    Originally posted by roygoh


    Thanks for your compliments.

    When did you visited Seattle? Or did you stay here for a while?

    OK, I will not tell you that I am working with M****soft....
    I had an academic exchange programme at University of Victoria on Vancouver Island in 1999.
    I visited Seattle for a few days... like the place a lot. took quite a bit of pics too, but they are all in slides and i don't have a scanner, so....
    Despite all the similarities and geographical proximity between vancouver and seattle, the moment you cross the border to states, you can feel it....

  17. #17
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    Originally posted by Moralis
    I used a radius of about 4 pixels. I think the halo effect may also be due to my inaccurate selection of the bridge cables.

    But there isn't much contrast between the cable and the sky when zoomed in, they tend to dissolve into one another, making selection difficult.
    4 pixels is too high for my taste, especially when you are working on a low resolution file. I usually use no more than 1.5 pixels even when working with high resolution files at 2048X1536.
    As complexity rises, precise statements lose meaning and meaningful statements lose precision.

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