Fishing

This is the discussion thread for the September 2010 Class.
ggroess
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Postby ggroess » Wed Sep 15, 2010 10:09 pm


I take it that there won't be a class discussing hue clocks, since they are already being used in discussions.  I appreciate your explanation of them, but I still don't understand them.


We actually cover them in greater detail coming up very soon...We do introduce you to them early so that you can see what is going on.  Your point is well taken though..


First, there is no pure color in the real world.  If you wear a brand new white tee shirt, but you are standing outside, the shirt will have other colors in it....maybe the red reflection from the bricks in the building in front of you, some yellow or orange from the sunlight, etc.  Since these colors are actually in the tee shirt in the picture, then when you place a hue clock on the shirt, you will see trace amounts of this, correct?  Why would you remove that if it's actually there?  Not to mention that removing it would change the other colors in the picture.


That sounds more like a philosophy question....Some would argue that you should not change them; I would argue that the camera gets it wrong more often than it gets it right.  I see hundreds of images every day and very few can stand up without any adjustment.  All of this comes down to what is acceptable to you.  If you can accept a color cast where one reasonably should not be then I guess you have made your point.  I can tell you that any digital image captured by today's technology is a poor representation of the reality...It is a calculated average of the information available in the instant the shutter was clicked.  Our eyes and brains can process so much more data that what we see will never be what we can capture.  I will say it is light years better than even 5 years ago but it still does not measure up to a nice Kodachrome...(Opening a beer now.. ;D.)


Okay, so you have a hue clock pinned to something....say the sky.  What can you tell from it?  There is no purple in the sky(as you mentioned), so how do you know the hue clock indicates purple when there is no purple on the hue clock?  Then, how do you get the hue clock to read the color you want....that is, however you saw on the hue clock that there was purple in the image, how do you change things to eliminate the purple so it no longer shows up on the hue clock?....and how do you know whether to use LAB or RGB?


Well, for starters you need to remember the color wheel and what colors make up other colors...for instance you need to know that red+yellow = orange.  When you bring the experience to the table you begin to figure out what needs to be changed.  The choice of RGB or LAB comes down to goals.  If my goal is to adjust the contrast and tonality I might use both as I did with your fishing image.  Most often I start in LAB because I can have a sledgehammer effect on the image and if it is not too important I can be done fast with great results.  There are those images that just won't wash clean no matter how hard you scrub...and that is when we have to have more than the PS sliders. 

I use the numbers in the Hue Clocks to tell me where in the "range" of the color I am...for instance if the range of the color is 0 to 255 then 127 is in the middle of the curve.  When I look at the hue clock with RGB numbers displayed I can see where in the curve to adjust the lower the numbers the closer to the highlight side...the higher the numbers the closer to the dark end of the curve. 


See Greg, there is so much that needs to be understood with the software in order to use it properly, that I don't know if I'm coming or going.  I don't know where to start, what to do, how to do it, or why we do it. 


I'm hopeful that you will....


That's okay though Greg, I knew that before I signed up for the class.  I figured that if I was able to learn to use 1% of CM, then it would be more than I was using before, so I would come out ahead in the end. :)


I'm hoping for 50% myself...I think I can get you that far...

Greg

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Postby imported_julie » Wed Sep 15, 2010 11:35 pm

Hi Art

This may help. When I started using hue clocks I stuck a piece of paper to the side of my screen which told me where the hue clock should be for certain things eg plants, sky and people. It really helped to identify what was wrong, especially if it was subtle in the original but very wrong when colour was boosted.
I cant remember where I got this but Greg will be able to tell you.
I found this really useful to help guide me in corrections as I have a lousy memory for details (good on concepts though). I still have a piece of paper stuck to the side of my screen with blue tack and its a great prompt. Sometimes I don't do something for a while and when I need to rediscover it its right there.

Julie

leeharper_admin
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Postby leeharper_admin » Thu Sep 16, 2010 9:52 am

Hi Art,
If you wear a brand new white tee shirt, but you are standing outside, the shirt will have other colors in it....maybe the red reflection from the bricks in the building in front of you, some yellow or orange from the sunlight, etc.  Since these colors are actually in the tee shirt in the picture, then when you place a hue clock on the shirt, you will see trace amounts of this, correct?  Why would you remove that if it's actually there?

The reason that it would be worthwhile correcting this white t-shirt - so that it looked neutral - is because nobody would have seen the red reflection from the bricks.

The idea is this: if the camera "sees" - and records - something that a person would not have noticed, the image will look better if our corrections make the image look how the scene would have done to us (had we been there).

There are two optical illusions to account for: Chromatic Adaptation, and Simultaneous Contrast.

Chromatic Adaptation means that our brains neutralize colored lighting (the same thing that a camera's white balance setting attempts to do). The effect is that we would see the t-shirt as being white, even if the camera didn't.

Simultaneous Contrast is to protect us from being eaten by tigers! It means that when we see a lot of things that are approximately the same color (imagine that you are in a forest, surrounded by green trees), our brains trick us into seeing more variation in the colors than actually exists; therefore, we would see lots of different types of green (blue-greens, yellow-greens...) but your camera would not - so any photograph that you take in that kind of situation will be visually unsatisfactory without correction (and it isn't the kind of correction that it is possible to make with a slider - you need to use curves).

Simultaneous contrast won't crop up until the final week of the class, so no need to worry too much about it at present; but - if you accept that your photographs will look better if you make them look like what you would have seen (rather than what the camera saw) - you need to start making things that 'ought to be neutral', neutral (equal red, green, and blue values on the hue clock).

Don't worry about picking this stuff up - none of us were born knowing how to do this; it will come in time...

All the best,
Lee.

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Postby mikemeister_admin » Thu Sep 16, 2010 12:07 pm


Numbers?

If RGB  then 100,100,100 is a neutral.  50,50,50  ---  0,0,0 black plugged.  255,255,255  white blown out.

LAB xxx,0,0 is a neutral.  positive warm, negative cold.   

Skies should not be cyan.  LAB-  b is negative,  a is near zero.  (can be slightly negative)

Faces - A and B  positive  A more than B except small children and light skin.

Greenery  -  A neg B posi.  B is more positive than a is negative

Curves are a graphical method to convert colors.  Move a curve and the color changes.  If it is on a 45 degree line, it is original. 


I appreciate your response, but I have no idea what all of that meant.  Whatever all of that means is way over my head.

leeharper_admin
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Postby leeharper_admin » Thu Sep 16, 2010 12:43 pm

Don't worry - this will be discussed later in the course, and there will be videos, PDFs, and the forum to help you make sense of it. If you look again at the course outline (in the Enrolment thread on the forum), you are in week 2. In week 3 these numbers will begin to be introduced; in week 4 the details will be filled in some more (and this will be continually discussed in the remaining weeks).

From reading your postings it appears that you are becoming frustrated by things that will be discussed (in depth) later in the course. Some of the other participants seem to have some familiarity with some of the material yet to come, and that appears to be making you feel as if you have missed something that the other participants have cottoned-on to (forgive me if I am misinterpreting the source of your frustrations).

For the purposes of the material presented in week 2, there are only four pieces of information that you need to concern yourself with (everything else will come later):


  • If something in a photograph would have appeared neutral (black, white or grey) to the photographer, your image will look better if you correct it to be neutral. You can use the wizard to do this, or you can use the method that is shown in the

Keeping Abe Honest video. Either method will correct the numbers describing each pixel. If you are working in RGB, it will make each number equal; if you are working in Lab, it will set the numeric values for the A and B channels both to 0. (But again, if the numbers are bothering you, don't pay any attention to them yet).
  • With the exception of high-key images, your photographs should have a shadow value that is as dark as possible - and (since black is simply very dark grey) without color. Again, you don't need to worry about the actual numbers that make this happen until next week.

  • With the exception of low-key images, your photographs should have a highlight value that is as light as possible - but this value might not be neutral (you need to be a little careful with this one).

  • When setting shadow and highlight points you should choose to set them on the darkest and lightest points that contain meaningful detail (i.e., a lightbulb might be literally the brightest area within the image, but for the purposes of setting a highlight point you should ignore it).


  • Please don't lurk! If you have more questions, then we are all happy to answer them (it's to everyone's benefit, as Greg said) ;)

    Cheers,
    Lee.

    mikemeister_admin
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    Postby mikemeister_admin » Thu Sep 16, 2010 1:41 pm

    Hey there Lee!

    I appreciate the encouragement, but it isn't that I am frustrated, it's that I am at a basic level and the class is at an intermediate level.  The terminology itself is over my head, so any explanation using that terminology won't make any sense to me.

    I wouldn't want the class to drop down to my level as that would bore the others here, so it's best if I just lurk and see what others do.  I might be able to pick up some tips along the way, and if not, that's okay.  I can see that I'll never understand CM enough to be able to use it as my main editing software, so anything I do learn about it will help me when I use the other tools in Photoshop.  No matter what, I will learn something. :)

    ggroess
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    Postby ggroess » Thu Sep 16, 2010 7:51 pm

    Art,
    The class is as much yours as anyone else.  I will keep at it with you until you get what you came for...

    The class can be taught at any level needed...from super advanced to super easy...My job is to figure out what you need and try to get it to you...at your level and speed. 

    I hope I am polite but persistent in this regard...
    Greg

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    Postby mikemeister_admin » Thu Sep 16, 2010 10:00 pm


    Art,
    The class is as much yours as anyone else.  I will keep at it with you until you get what you came for...

    The class can be taught at any level needed...from super advanced to super easy...My job is to figure out what you need and try to get it to you...at your level and speed. 

    I hope I am polite but persistent in this regard...
    Greg


    Hey Greg!  I know you want to help me, and I do appreciate that, but the class is beyond my abilities.  You can't make it easy enough for me because I don't have the basic knowledge that a person needs to understand what is being taught. 

    It's like trying to teach someone trigonometry when they don't know how to add or subtract.  If the teacher is trying to teach trigonometry to the class, he doesn't want to have to try to explain the principles of arithmetic to one person.  It isn't fair to the others, plus the student should have had that background before they took the class.

    The others here must have more experience since they aren't asking many questions, so to hold up the class to try to explain the basics to me, wouldn't be fair to them or you.  I've been in classes where one of the students wasn't "up to par" with what he needed to know for the class, and it really slowed down the class.  I don't want to be that person, which is why I said that I'm better off just lurking and watching the others.  They deserve your full attention, I don't. :)

    ggroess
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    Postby ggroess » Thu Sep 16, 2010 11:52 pm

    Fair enough...but I do check to see who is watching and I might give you a nudge or two because I want you to get what you came here for...
    Keep asking questions when you feel the need and I'll give whatever I can to help you out. 

    Greg


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