how do you add luminosity to a photo?

Canon EF 70-200mm f/4.0L USM

08/22/2005 04:39:54 PM · #1

Please Help. I wanted to add luminosity to a photo and have forgotten how. (using photoshop) I have played for an hour now and still no luck so figured someone here might be able to help me. As a beginner (who has already had one disqualification) can anyone tell me if we can alter color and luminosity with basic editing? I have decided to brave the challenge world once more and want to make sure I do not get DQ'd this time. Thanks in advance for any help you can offer me.

Message edited by author 2005-08-22 16:40:15.

cpanaioti

Canon EOS-40D

Canon EF 70-300mm f/4.5-5.6 DO IS USM

08/22/2005 04:41:56 PM · #2

Levels and/or curves usually helps in that area as well as hue/saturation.

As long as these are applied to the entire image then they are legal in basic editing.

troberge

Canon EF 70-200mm f/4.0L USM

08/22/2005 05:49:15 PM · #3

For some reason there is no option under hue/saturation. I remember on another photo I actually had an option to adjust the luminosity. I checked under levels and curves and neither of those had the word luminosity anywhere either.

Canon EF 70-300mm f/4.5-5.6 DO IS USM

08/22/2005 06:48:35 PM · #4

I'm not quite sure what you mean by "luminosity" here, but under Levels, the center arrow affects your gamma and the left and right ones your black point and white point, which in turn affect luminosity. Brightness (in Brightness/Contrast) will affect it (as will contrast, by raising it in some parts and lowering it in others, but I get the feeling you're looking for a uniform effect), Lightness (in Hue/Sat) will affect it, either for all colors or per channel, Selective Color will let you play with it per individual color by changing the amount of Black, the Shadow/Highlight tool allows you to change it in subtle fashions for given existing ranges of luminosity, and under the Exposure tool, you can change your EC, black point, and gamma, all of which affect it in slightly different ways. All of these, as long as they're applied to the entire image, are legal within Basic Editing.

If none of those is what you're looking for, you'll probably have to rephrase your question. The word "luminosity" isn't going to show up in any of the adjustemnts in Photoshop that I know of, except for a "preserve luminosity" option in some of the color adjustment tools that I don't think is what you're looking for.

cpanaioti

Canon EOS-40D

08/22/2005 06:51:35 PM · #5

Originally posted by troberge:

No they don't but adjusting the curves/levels changes the luminosity of an image.

scuds

Canon EOS-30D

Sony 24-70mm F4 Vario-Tessar T* FE OSS

08/22/2005 07:08:17 PM · #6

shadows and highlights has a luminosity sliding bar

Bear_Music

Samsung Galaxy S24 Ultra

08/22/2005 07:23:10 PM · #7

Originally posted by troberge:

"Luminosity" is one of the options for layer modes. You got standard, burn, multiply, dodge, hue, color, luminosity, and a lot more. In basic editing ONLY "standard" is a legal layer mode. Anyway, layer mode "luminosity" doesn't let you change luminosity per se, it just makes changes based on relative luminosity of the layer being blended and the udnerlying layer.

Basically, for a photographer, "luminosity" in an image is pretty much equivalent to contrast; less contrast = less luminosity. This isn't precisely true, because it's more a function of tonal range than it is of contrast, but these go hand in hand. If you have a flat image that you want to make "more luminous" you would go the "levels" adjustment and slide the left or right slider (or both) towards the center, then adjust the central slider to get the overall lightness/darkness right.

You can do this more precisely with curves, but they take a lot more practice.

Here's something you can try that has a huge effect on luminance of the image. starting with a flat image you want to make more luminous:

1. hit cntrl-alt-tilde (~) and then cntrl-J â�� this will create a new layer mask for the brighter portion of the image.

2. Click on the BG layer to make it active again.

3. hit cntrl-alt-tilde, hit cntrl-shif-I toinvert the selection, and cntrl-J to make a layer mask for the darker portion of the image.

4. Change the layer mode of the first to "screen" and the second to "multiply".

5. Now adjust the relative opacity of the 2 layers.

If you have an image that is too contrasty, you can use the same steps but "multiply" the highlights and "screen" the shadows.

Experiment with different layer modes for both, to see the effect this has.

Robt.

08/22/2005 08:05:43 PM · #8

Originally posted by scuds:

shadows and highlights has a luminosity sliding bar

Er, not on mine (Amount, Tonal Width, Radius, Color Correction, Midtone Contrast, Black Clip, White Clip). What version of Photoshop are you using?

08/22/2005 08:15:24 PM · #9

Originally posted by bear_music:

Basically, for a photographer, "luminosity" in an image is pretty much equivalent to contrast; less contrast = less luminosity.

Er, you're using either 'contrast' or 'luminosity' in a manner that I'm not accustomed to. The way I've always seen it defined, luminosity is the absolute value of a brightness of a pixel (e.g. if you desaturate/greyscale an image, what you're left with is a bunch of pixels with nothing but the luminosity value left, from 0=black to x=white, where x depends on the bitrange). Contrast is a measurement of how much the luminosity spreads throughout the image (i.e. a zero contrast image is a single color with no spread at all, while a high contrast image will spread to the maximum and minimum values of the bitrange, and more importantly to the eye, do so over small regions of the image to which the eye is drawn).

Good catch on the layer mode, though.

scuds

Canon EOS-30D

08/22/2005 08:17:00 PM · #10

Originally posted by Zed Pobre:

Originally posted by scuds:
shadows and highlights has a luminosity sliding bar

Er, not on mine (Amount, Tonal Width, Radius, Color Correction, Midtone Contrast, Black Clip, White Clip). What version of Photoshop are you using?

uhhhh, hummmm, PS scuds version has eveything I want!

Dang, I thought it was there, but it ain't!
There's a luminosity thingie on Adobe Camera Raw (luminance smoothing)

Mattel Barbie Photo Designer Digital Camera

08/22/2005 08:21:12 PM · #11

Originally posted by scuds:

There's a luminosity thingie on Adobe Camera Raw (luminance smoothing)

That's very, very different. That's a heavy-handed de-noising (smoothing) algorithm. If you don't have access to anything better (NeatImage, Noise Ninja, etc.), and you prefer softness to noise, you can use that to take care of a grainy image.

nsbca7

08/22/2005 08:23:45 PM · #12

Originally posted by Zed Pobre:

Not on mine either. I'm using CS. I find the Shodow/Highlight box is one of the best places to add luminosity regardless of whether there is actually a "luminosity" setting or not.

GinaRothfels

Olympus OM-D E-M5 Mark III

Olympus 8mm f/1.8 M.Zuiko Digital ED Fisheye PRO Lens

08/22/2005 08:24:34 PM · #13

Originally posted by bear_music:

Originally posted by troberge:
For some reason there is no option under hue/saturation. I remember on another photo I actually had an option to adjust the luminosity. I checked under levels and curves and neither of those had the word luminosity anywhere either.

"Luminosity" is one of the options for layer modes. You got standard, burn, multiply, dodge, hue, color, luminosity, and a lot more. In basic editing ONLY "standard" is a legal layer mode. Anyway, layer mode "luminosity" doesn't let you change luminosity per se, it just makes changes based on relative luminosity of the layer being blended and the udnerlying layer.

Basically, for a photographer, "luminosity" in an image is pretty much equivalent to contrast; less contrast = less luminosity. This isn't precisely true, because it's more a function of tonal range than it is of contrast, but these go hand in hand. If you have a flat image that you want to make "more luminous" you would go the "levels" adjustment and slide the left or right slider (or both) towards the center, then adjust the central slider to get the overall lightness/darkness right.

You can do this more precisely with curves, but they take a lot more practice.

Here's something you can try that has a huge effect on luminance of the image. starting with a flat image you want to make more luminous:

1. hit cntrl-alt-tilde (~) and then cntrl-J â�� this will create a new layer mask for the brighter portion of the image.

2. Click on the BG layer to make it active again.

3. hit cntrl-alt-tilde, hit cntrl-shif-I toinvert the selection, and cntrl-J to make a layer mask for the darker portion of the image.

4. Change the layer mode of the first to "screen" and the second to "multiply".

5. Now adjust the relative opacity of the 2 layers.

If you have an image that is too contrasty, you can use the same steps but "multiply" the highlights and "screen" the shadows.

Experiment with different layer modes for both, to see the effect this has.

Robt.

You can't use different layer modes for basic editing.

scuds

Canon EOS-30D

08/22/2005 08:28:33 PM · #14

Originally posted by GinaRothfels:

You can't use different layer modes for basic editing.

You are abso-freaking-lutely correct!

Originally posted by dpc rules page:

Layers: Only Adjustment Layers (or the non-Photoshop equivalent) may be used. An Adjustment Layer is one that does not contain any pixel data, but rather is a special, non-image layer that lets you experiment with color and tonal adjustments to an image without permanently modifying the pixels. Adjustment Layers must be applied in Normal mode. All other types of layers (including those that contain pixel data or masks) and all other blending methods (modes) are prohibited. Changing the opacity of an Adjustment Layer is permitted.

Message edited by author 2005-08-22 20:29:47.

troberge