What's the difference between adding contrast and simultaneously darkening highlights and brightening shadows in Lightroom?

Question

In Lightroom 4, when editing a RAW file, what's the difference (if any) between the following edits:

A). +30 Contrast

Or

B). -30 Highlights, +30 Shadows.

Do these do the same thing?

Asked by Eric B

Answer

Well, as they say, a picture is worth a thousand words. The GIF animation below shows +30 Contrast, +30 Highlights/-30 Shadows, -30 Highlights/-30 Shadows:

The differences between the three are subtle, however there are indeed differences. Contrast increases the spread of tones across the tonal range, so technically speaking, +30 Contrast is more like +30 highlights/-30 Shadows than it is like -30 Highlights/+30 Shadows. However it is dissimilar from both, in that adjusting contrast also affects color saturation as well as tonal range. This improvement to color contrast is evident between the first two frames of the GIF animation...the colors are more washed out in the +30H/-30S frame (most readily visible in the fence.) Adjustments to contrast are also more likely to affect the entire dynamic range (every tone in the image), where as highlight and shadow adjustments are purposely designed to affect a restricted range of tones.

Answered by jrista

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How to photograph glass without reflections and shadows?

Question

I'm working on Image processing issue and I need to take picture from automotive glass.the camera is mounted at top and the glass lays down at the bottom. I put a black textile at the back of glass . the main problem is how can I cancel reflection of camera image into the glass? how should I light the object to give best result and have no shadow and reflection of near objects? thanks

Asked by Farzad Sagharchi

Answer

When you have a reflective surface like glass, the angle of incidence of the light equals the angle of reflection. So if the light comes from 45 degrees from the right, it will reflect back 45 to the left. If it's directly over the glass, it will reflect straight back (at the camera then).

source: http://en.wikipedia.org/wiki/File:Reflection_angles.svg

So you want your lights far enough to the sides that you cannot see that reflection (I'd use at least two lights, one on either side). In the figure below, if P is your light source, the light will reflect off the glass to Q. If the camera is in the middle (where it says "normal") it will not see the glare of the reflection (this assume a narrow beam of light- with larger lights, rather than one narrow line between P and Q there is a much wider band of light.

In order to remove the reflection of your camera, as James Youngman said, a polarising filter will reduce it. To eliminate it you want to do one (or both) of two things:

• Move the camera slightly off-axis if you can, so that it's not exactly overhead. Using the same angle of incidence/reflection, the reflection of the camera will not come straight back up into the camera. Like moving to the side of a mirror until you can't see your reflection. This can cause perspective problems however

• The other solution is do this work in a dark place. Illuminate your subject with lights that have grids, snoots, or barn doors to focus the light on the subject, so that your camera does not get light on it. If it is in the dark it will be invisible. You can use black cards or fabric to keep the light from illuminating the camera.

• You could also fashion a black board with a hole in it for your lens. Stick the lens through and take your photos. The reflection will then be of a black surface with a small, dark round hole, which may not show up, or can more easily be edited out in post processing

A good source for all of this is the book Light, Science and Magic

Answered by MikeW

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How do I properly do shadowless product photos?

Question

My friend asked me to create a photo like this. I noticed that its shadowless and my first question is whether it was setup to be shadowless, or was it made shadowless in post? How many lights are involved here? I think there's one for the background, and one above the product pointing something like 30 degrees down, and then some reflectors to the side. Just guessing.

I did some Googling and came across this setup. How could that be shadowless? Looks like the product is a few feet above the ground, which is a white seamless background, and the camera and all the lighting are all pointing down. How could there be no shadow on the ground?

Thanks!

Answer

Also on Digital Photography School, Alex Koloskov walks through creating attractive product photos. And in his blog he shows how to achieve almost the same results with $55 light setup. His blog in general is very educative, as he's professional product photographer who regularly shares the setups used to get the results he got.

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How does one best deal with shaded faces in bright sunlight?

Question

When photographing people in bright sunlight, parts of faces are often shaded by hats or by their own contours. This creates highly-contrasted faces, and either a very bright background or very dark faces.

Using flash doesn't always help, especially when photographing a large group (~10 people) from a little distance.

What's your solution for this common situation?

Answer

For me, I have reflectors which can be positioned (sometimes with help) so as to fill in the light on the subjects. There are some reasonable 5-in-1 options out there, I have a 43" version of one of them and it works very well, folding up to a pretty small package and giving lots of options for cooling or warming the light as needed.

If you don't have reflectors, but do have larger, bright, surfaces you use, then that too is an option. What it really boils down to is getting some of generally available light redirected to the place you want it and, for that, many reasonably reflective items will help a great deal if sufficiently large. Heck, it can even by some bristol board or shiny wrapping paper, I've done both.

Anyways, those are what I do and, to be honest, I prefer that sort of light over a flash anyways. Fill flash can harsh, especially when it is on camera, and so I prefer to avoid it.

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How to properly do shadowless product photos?

Question

My friend asked me to create a photo like this. I noticed that its shadowless and my first question is whether it was setup to be shadowless, or was it made shadowless in post? How many lights are involved here? I think there's one for the background, and one above the product pointing something like 30 degrees down, and then some reflectors to the side. Just guessing.

I did some Googling and came across this setup. How could that be shadowless? Looks like the product is a few feet above the ground, which is a white seamless background, and the camera and all the lighting are all pointing down. How could there be no shadow on the ground?

Thanks!

Answer

Also on Digital Photography School, Alex Koloskov walks through creating attractive product photos. And in his blog he shows how to achieve almost the same results with $55 light setup. His blog in general is very educative, as he's professional product photographer who regularly shares the setups used to get the results he got.

Check more discussion of this question.