14 replies to this topic

[olof]

Hi There,

I made this picture of this nice shark during my visit at the bahamas. I edited it with the guide as described on this site.

This is the best what I can make of it. Any idea what can be done to improve?

Thanx

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[PRC]

Hi Olof,

OK I will take a go.

It obviously has a bad blue cast - often if you attack these in RGB I find that you end up with all sorts of other problems, such as the purple / magenta cast in the water.

So FWIW I usually go LAB.

Big benefit here is separation of the luminance and colour information.



To be fair if you have a higher res version and better yet RAW then we could probably get better.

To get to the above some fairly extreme changes were called for in the curves.

Paul c

Edited by PRC, 18 February 2010 - 01:20 PM.

[mborosch]

Duplicate the original layer in PhotoShop and correct for the blue water in one layer, then correct for the shark in the other layer, then create a mask that combines the best of both layers, a lot can be done with masks. You will never be able to correct for both on the same layer. From what I've always been told in the past converting back and forth between color modes eventually eats away at the image quality, so I personally stay away for switching color modes.


Mark

Edited by mborosch, 19 February 2010 - 06:04 AM.

[tdpriest]

Try converting to a black and white image, then pushing the contrast so the darkest tones in your image are pure black and the lightest pure white. An example:

http://www.flickr.co...57622432026069/

Tim

Edited by tdpriest, 19 February 2010 - 06:51 AM.

[olof]

Thanks for the tips. I know it's not the highest quality. Had to compress it since I didn't have a server available to post pictures in original size.
So how's that with the curves? Any place where I can read a bit more about how that workes? Most of the time the auto curve function gives the best result I can get.

Thanks !

[mborosch]

Use layer adjustments when doing any color or tonal corrections, that way you never disturb the original pixels and you can play with the adjustment all you want and you will never harm the image. Check out the blending modes as well because they are very powerful as well. For example if I'm color correcting with a layers adjustments I might set the blending mode to "Color" that way it only corrects for color changes and not tonal changes and vise versa if I'm only doing tonal/contrast changes I would set the blending mode to luminosity so that the correction does not shift the colors around. Layer Adjustments are a fantastic tool as you can always undo them. Layer adjustments are a great way to dodge burn images as apposed to the forbidden dodge and burn tool. Again, think multiple layers with multiple adjustments.


Mark

Edited by mborosch, 19 February 2010 - 11:13 AM.

[Bentoni]

In Photoshop there are always dozens of ways to skin a cat. But I agree with 'mborosch.' Blending two separate images is the easiest way to go. In my example I corrected the color of the water to look a bit richer. Then I converted the second version to b/w (I left it in RGB mode) and stacked it as a separate layer on top. By adding a layer mask to the b/w layer you simply "paint" the color back in by masking out that portion of the image. If you had lit it from below, his dorsal side would still look a little blue from the natural light from above, so I let some blue bleed onto the shark on his back to make it look more natural. This method works for this image because sharks are usually not brightly colored anyway.

[tdpriest]

This is a 20-second Photoshop CS4 conversion: channel mixer (monochrome; green>red>blue slider), levels and curves.



Tim

[mborosch]

I stand corrected switching color modes from RGB to LAB does not do any damage to the image integrity. I remember hearing this years ago, but really got to thinking about it the other day, so I consulted with one of the big time photoshop trainer guru's. He said there is no loss of quality in just switching color modes. However switching back and forth between color profiles can cause a loss in image integrity.

• Switching from say, Adobe RGB to sRGB will degrade because there's less colors in sRGB. From there, there's no reason to switch back to Adobe RGB from sRGB because Photoshop can't add colors.

• Switching from RGB to CMYK will also change the image because it has to change the colors to fit into CMYK's color space. Unless you have your undo's or saved a copy of the original, there's no going back to the original RGB, as those colors are gone so now PS will interpret best it can when it converts.


Thanks
Mark

[tdpriest]

...I usually go LAB.
Big benefit here is separation of the luminance and colour information...

This technique can be useful, but I don't use it when making a monochrome conversion: it sounds as if having a luminance channel and taking the tonal information from it would be a good idea, but, in fact, this usually creates a very bland image.

By taking most of the tonal information from the green channel of an RGB image, most of the image's detail is preserved; the red channel contributes to a bright background and sunburst and the blue channel adds brightness to the shadows. I often use very little information from the blue channel and only enough red to produce a grey water background. The trick is maximise contrast across the image, whilst preserving the silhouette and detail of the subject.

Tim

Edited by tdpriest, 25 February 2010 - 05:37 AM.

[Tjsnapper]

Hi all, here is my take on it:
I separated the shark from the background using the magnetic lassoo tool, edited the shark on another layer using curves in all three of the RGB curves. Then noise ninja, then a little dodge and burn.
I was trying to retain the overall exposure of the image with as you can lose the eye / darker areas of the image.
This is just a 2-3 minute job so nothing too serious If i was going to spend more time on it wi would sort out more of the water etc

Tristan

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Edited by Tjsnapper, 02 March 2010 - 06:59 AM.

[PRC]

Great job Tristan, don't like the purple cast on the water and the underside of the shark looks a bit blown to me but am sure with a bit more work that could be sorted. Noise wise yours looks the cleanest

Interesting to see and learn from the various attempts here.

Thanks all,

Paul C

Edited by PRC, 02 March 2010 - 10:15 AM.

[Tjsnapper]

Great job Tristan, don't like the purple cast on the water and the underside of the shark looks a bit blown to me but am sure with a bit more work that could be sorted. Noise wise yours looks the cleanest

Interesting to see and learn from the various attempts here.

Thanks all,

Paul C

Thanks Paul,

I am doing this on a very old laptop that can only just about run PS3 LOL and the screen is not colour corrected etc but I am tempted to have a go at the water when I get home Oh, and you are right, \you can never stop learning new techniques

Tristan

Edited by Tjsnapper, 02 March 2010 - 12:02 PM.

[PRC]

In some ways it would be interesting to put up some images such as this that are how can I put it - 'less than ideal' and see some of the results that can be dragged out of them.

To be fair I have loads of images that are er - 'less than ideal' and would be happy to contribute .

Paul C

[Tjsnapper]

In some ways it would be interesting to put up some images such as this that are how can I put it - 'less than ideal' and see some of the results that can be dragged out of them.

To be fair I have loads of images that are er - 'less than ideal' and would be happy to contribute .

Paul C

In fact most of my images are "less than Ideal" LOL, but it is amazing how much you can salvage, Acutally on my last liveaboard trip I ended up doing a fair bit of this work for other divers as I was hit by a bad cold the day after getting on board so had plenty of time to kill ascould only manage 7 dives out of the 21 - You have no Idea how frustrating it was watching guys come out of the water with images of sharks just a few feet away. As most of them had P&S cameras there was no white balancing taking place so i had a little practice at "improving" images.
I have, however, met with some wiremen in the past who are absolutely amazing at "retouching" Images and would love to have their skill.

Edited by Tjsnapper, 03 March 2010 - 02:44 AM.