3 channel LAB HIRALOAM with an HDR image

ruttrutt Registered Users Posts: 6,511 Major grins
edited May 10, 2007 in Finishing School
147827248-L-1.jpg147869540-L.jpg

Above is before/after of David (Devbobo) Parry's beautiful HDR image posted in the Whipping Post. When I first saw this, I thought, "He's nailed it; nothing much I can do for it."

But then I thought I'd try out a recent Margulis idea: 3 channel HIRALOAM in LAB and that's what you are seeing above (and all that you are seeing.)
  1. Convert to LAB, duplicate layer
  2. HIRALOAM with all three channels selected. I this case, the original was low res, so the radius was just relatively low, about 7. Full res, it would have been more like 30 or so, I'm guessing. Left amount very high for now: 70%
  3. Convert to RGB without flattening. Duplicate the HIRALOAM layer and set blending mode of one layer to darken and the other to lighten.
  4. Decrease opacity of lighten layer to about 50%
  5. Duplicate background layer below the two HIRALOAM layers and merge these three layers.
  6. Play with opacity of the merged layer. Maybe 80%?
  7. Done
What's going on here? When I first saw this image, I was blown away by it, but then wondered if it had a real light point. I measured and couldn't find one. So I tried curves and/or blending to make one. My reasoning was that an HDR image should really use the whole contrast range available. But this didn't look right no matter what I did. The image isn't globally too dark.

HIRALOAM is a local contrast enhancement. So one of the effects of this move was to make the lightest parts of the image a little lighter and thus establish true light points in the surf reflections. It also intensified the dark points in the rocks. It did this without losing detail in either area, because I was careful with my opacities.

It also brought out detail in the rocks and sand as might be expected for HIRALOAM sharpening.

The unconventional thing is the use of all three LAB channels for the HIRALOAM USM which it also intensified the colors in sky, particularly the red of the clouds. You may need to download and look at it in PS to see this in my final version (this is a case where my browser shows the image considerably ligher than PS does.) But let's look at the HIRALOAM layer at full opacity and amount:

147880116-L.jpg

Here you can easily see the local saturation in the sky, you can see how the move will lighten the surf. You can even tell that it will lighten too much relative to darkening.

With a full res original, it would probably be worth sharpening the L channel separately form the A+B channels in order to get richer colors even in the far highlights, where I cut the opacity for this particular attempt...
If not now, when?

Comments

  • devbobodevbobo Registered Users, Retired Mod Posts: 4,339 SmugMug Employee
    edited April 29, 2007
    Hey Rutt,

    I love what you have done here :D

    I will give this a go on the original a bit later. I am considering getting this in a large canvas, but when I see your changes first.

    Cheers mate,

    David
    David Parry
    SmugMug API Developer
    My Photos
  • Scott_TScott_T Registered Users Posts: 13 Big grins
    edited May 9, 2007
    Really great shot. Also love the sharpening. Is there a HIRALOAM tutorial posted? I've been looking, but seem to be missing it....

    Thanks and kudos to the great work!

    Jealously,
    Scott
  • ruttrutt Registered Users Posts: 6,511 Major grins
    edited May 10, 2007
    Scott_T wrote:
    Really great shot. Also love the sharpening. Is there a HIRALOAM tutorial posted? I've been looking, but seem to be missing it....

    Thanks and kudos to the great work!

    Jealously,
    Scott

    I know so much more about HIRALOAM than I did when I wrote the LAB book chapter summary, the portrait technique summary (which illustrates a HIRALOAM step) and even when Nik wrote his chapter summary of PP5E. I've been meaning to write something. But for now you can see this post.
    If not now, when?
  • ruttrutt Registered Users Posts: 6,511 Major grins
    edited May 10, 2007
    Scott_T wrote:
    Really great shot. Also love the sharpening. Is there a HIRALOAM tutorial posted? I've been looking, but seem to be missing it....

    Thanks and kudos to the great work!

    Jealously,
    Scott

    I know so much more about HIRALOAM than I did when I wrote the LAB book chapter summary, the portrait technique summary (which illustrates a HIRALOAM step) and even when Nik wrote his chapter summary of PP5E. I've been meaning to write something. But for now you can see this post.
    If not now, when?
  • Manfr3dManfr3d Registered Users Posts: 2,008 Major grins
    edited May 10, 2007
    The image looks magnificent and your explanation of the
    technique is great. Thank you for sharing. I have it
    bootmarked to try it myself once my Pantone Huey Pro arrives.

    thumb.gif
    “To consult the rules of composition before making a picture is a little like consulting the law of gravitation before going for a walk.”
    ― Edward Weston
  • ruttrutt Registered Users Posts: 6,511 Major grins
    edited May 10, 2007
    Manfr3d wrote:
    The image looks magnificent and your explanation of the
    technique is great. Thank you for sharing. I have it
    bootmarked to try it myself once my Pantone Huey Pro arrives.

    thumb.gif

    Pantone Huey. Slowly I turned. Step by step. Inch by inch...

    Seriously. Monitor calibration is overrated. It's neither necessary nor sufficient for good color correction and image enhancement. What's important is having non-broken calibration. If you are in the ballpark (and the Huey [slowly I turned] never got me there) then you must learn to measure color values to get the best possible results (and in this case I started with a great image and so we are really talking about best possible, not just OK.) And the technique I finally settled on really doesn't require very exact calibration. I relied on the very exaggerated HIRALOAM layer before I turned down the opacity to know what I was doing. There is nothing subtle about that.

    I've posted a lot about this. Here's an example. But even after this post the thread turned to the issue of how best to calibrate. Someday soon I'm going to write a manifesto. :rutt
    If not now, when?
  • LiquidAirLiquidAir Registered Users Posts: 1,751 Major grins
    edited May 10, 2007
    I have wondered about local contrast enhancement in the A and B channels (I prefer the term local contrast enhancement to HIRALOAM because it focuses on what it does rather how you do it). So far I have shied away from it becuase of the significant risk of messing up the neutral areas, but it looks like some careful use of blending modes may work to protect the neutrals. Clearly I need to give it a shot.
  • ruttrutt Registered Users Posts: 6,511 Major grins
    edited May 10, 2007
    LiquidAir wrote:
    I have wondered about local contrast enhancement in the A and B channels (I prefer the term local contrast enhancement to HIRALOAM because it focuses on what it does rather how you do it). So far I have shied away from it becuase of the significant risk of messing up the neutral areas, but it looks like some careful use of blending modes may work to protect the neutrals. Clearly I need to give it a shot.

    Sharpen only the L and you'll make no color changes at all.
    If not now, when?
  • Scott_TScott_T Registered Users Posts: 13 Big grins
    edited May 10, 2007
    Thanks!
    Thanks for the links Rutt.....Will post back after some reading!

    Scott
  • Scott_TScott_T Registered Users Posts: 13 Big grins
    edited May 10, 2007
    Another question....straying a bit off topic...

    I plan to buy the Photoshop Lab color book. I actually bought it once, but was ripped on ebay.....

    Anyhow would you also recommend buying Professional Photoshop: The Classic Guide to Color Correction (5th Edition)?

    Thanks,
    Scott
  • ruttrutt Registered Users Posts: 6,511 Major grins
    edited May 10, 2007
    Scott_T wrote:
    Another question....straying a bit off topic...

    I plan to buy the Photoshop Lab color book. I actually bought it once, but was ripped on ebay.....

    Anyhow would you also recommend buying Professional Photoshop: The Classic Guide to Color Correction (5th Edition)?

    Thanks,
    Scott

    Way off target. See: this post. And please post responses there not here.
    If not now, when?
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