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Old Mar 10, 2004, 4:08 PM   #1
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Default Color-Blind; Railyard, Locust Point - Baltimore 2004

Original image taken with a Sony F717 - 5 megapixel, fine jpg compression ratio.

The image was taken about 4:00 p.m. Because of a high fence around the yard, I placed the camera lens through a hole in the bottom of the fence, hence the concrete in the bottom of the image. The camera body was articulated such that the LCD screen on the back of the camera was facing up. EV was adjusted to move the histogram to the right without blowing out the highlights.



I captured the image with the intent of post-processing in B&W.



The image was desaturated and the layers palette opened then I cropped the top and bottom of the image. Three layer gamma curve masks were used to control three zones in the image. The three zones are outlined on the image below.



The copyright text was placed on a separate layer. This layer is moved to the top of the layers palette and the text typed on the layer. The final "print" is saved in a Photoshop file format. A copy of the image is made, resized, the layers flattened and saved as a jpg file. At this point, the unsharp mask may be applied and the image is sometimes converted to a grayscale mode.

The reason I use layers is to preserve as much of the image data as is possible without leaving gaps within the histogram.

What I did was similar to classic printmaking but instead of burning in areas, I adjust the tonal range with the gamma curve.

Enjoy,

Rod
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Old Mar 10, 2004, 4:20 PM   #2
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well first off.....that picture is great! i really like it!
second...wat(and where) is the "gamma curve"?
i've heard it several times but can't find it in photoshop (didn't really look TOO hard lol)
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Old Mar 10, 2004, 4:37 PM   #3
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Default Gamma Curve

In the photoshop menu:

>image>adjust>curves

Place the rodent cursor on the curve and click to ancho a point. Now place the cursor on the point, hold the right button down and move the curve. You can have as many anchor points as you wish. To remove an anchor point, grab it with the cursor slide it off the curve. Forming an S-curve is a good starting point. www.luminous-landscape.com has an article on curves.

If you have Photoshop versoin 6 or high, a curves adjustment layer is available in the layers palette.

>Window>Show Layers

In the layers palette, click on the B&W circle then select curves. Open an image before you do this.

Enjoy,

Rod
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Old Mar 10, 2004, 4:40 PM   #4
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ooh! really? lol i thought it was something completely different

thanks for that site again i should put it in my favorites.....
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Old Mar 10, 2004, 5:00 PM   #5
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This is a tough one to judge based on the goal of high contrast because you've got it on the left, but not on the right. It's a really interesting image to study, comparing back and forth between the color and the b&w versions because it quickly becomes obvious why there's that difference between sides. The left is tinged with yellow, the right with blue. When using Channels to convert to b&w, almost inevitably, the blue channel has the least contrast. Anyone have an explanation for this? If you do, pretend you're explaining it to an idiot--I got a D in college physics, and it was a course supposedly for non-science majors.
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Old Mar 10, 2004, 6:29 PM   #6
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Default Channel Noise

Barbara:

I have not read an article yet about signal to noise ratio and contrast in the RGB channels. If I had to guess, I suspect it may have something to do with the pixel sensors and the wave length of the RGB colors -

Update 3/11/04: A short explaination about digital image noise is at the following link: http://www.dpreview.com/learn/?/Glos...g/Noise_01.htm

In summary, noise is a function of the sensor and the processor. Futher, most sensors are not very sensitive to blue. To compensate for this lack of sensitivity, the blue channel signal is amplified, hence noise is also amplified.


I have tried using channels to obtain tonal range within an image but am never pleased with the results. One of the guidelines for using channels after the image is desaturated is the sum of the red, green and blue channel levels should be close to 100.

My approach is to work with adjustment layers and use whatever tool works to give the end result I want. Sometimes, my black and white images may have up to 6 layers, plus filters such as unsharp mask and Gaussian Blur. In a few images I have employed a contrast mask to even the tonal range out. For me, the end result is what counts not how I arrived at the image.

lol,

Rod
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Old Mar 10, 2004, 8:20 PM   #7
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Rod, do you ever use the method of converting to LAB mode and then using the Lightness channel for conversion? I find myself going to that one more often than the others.

Yes, there's that "rule" of having them add up to 100, but I've found that a little more of one thing or another--usually red--often works better.

Quote:
For me, the end result is what counts not how I arrived at the image.
Amen!
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Old Mar 10, 2004, 8:57 PM   #8
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Default duotone

Barbara:

I have tried duotone via lab colors but I forgot how to bring up duotone inks - more research.

In Photoshop there must be 4,000 ways to dot the "I".

BTW - I very much appreciate the challenge forum you run. It takes a considerable time committment to run a section of the forum. This latest challenge is helping photographers expand their vision. B&W is experience a revitalization and you are helping make it happen.

Thank You, Thank You, Thank You.

LOL

Rod
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Old Mar 11, 2004, 8:23 AM   #9
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Quote:
B&W is experience a revitalization
This may be true, but in the back of my mind when posting this challenge was a particular thing about monochrome: it forces a person to look harder, to analyze a scene for the type and quality of light, to see what's best described as the "bones" of the picture. No longer can we rely on color to carry us through; instead, we have to pay even more attention to--not just lights and darks--but to composition, to texture, even to meaning. I love b&w, actually prefer it to color, but it's constantly reminding me that I have a mountain of stuff yet to learn.
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Old Mar 12, 2004, 12:14 AM   #10
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Rod, although I can't say what's good or bad about the technical aspect of photos, I can say whether or not I like them, and I like this one very much. With the edits you made, it looks so much better than the original. Nice job!
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