HDR Photoquestion

[naznomore_92]

Is it possible to do an HDR photo using only one picture and adjusting the exposures of the other pictures in PHotoshop. I know it is cheating, but I want know if it is pssible. All's fair in love and photography. Thanks for any input.
Naz

[Abiciriderback]

I know the program I use for HDR is photomatix you have to use at least 2 photos (They recommend using 3 photos) shot at different exposures or it will not generate a HDR photo.

Ray Still

[Mr Yuck]

it is possible, but in many cases the result is not as good. The photo should be a RAW file. Just open Photomatix and drag the RAW file to the open Photomatix window.

In this case, it's not called an HDR, but rather, a Pseudo-HDR

I even converted a JPG to a 16-bit TIFF and did it...I was able to get a little bit of detail out.

[freygr]

Is it possible to do an HDR photo using only one picture and adjusting the exposures of the other pictures in PHotoshop. I know it is cheating, but I want know if it is pssible. All's fair in love and photography. Thanks for any input.
Naz

I would say NO. To get the extra detail you need at least three different exposures. One average, one for the shadows, and one for the highlights. There will always be shadow details which can be coached out using Gama and curve adjustments but it does not change the inherent range that digital cameras can capture. Please not you should be using the camera's RAW format as JPG is only 8 bits per channel not the 12-16 bits in most RAW formats, and that is allot more range than a JPG saved image.

[Medley]

In digital cameras, the brightest stop contains 50% of the total information in the image. The next stop contains 25%, the third 12.5%. and so on down the line. The theory behind HDR imaging is to capture each stop as the brightest area in several different exposures, and combine them, creating an image that has more detail than the camera is capable of capturing in any one shot.

What you're describing is properly called tone-mapping. Tone mapping definately has its place in digital photography, and can substantially improve an image, but should not be confused with HDR.

Incidentally, if you try to do what you're suggesting by using Photoshop's Merge to HDR command, Photoshop will tell you that there isn't enough information to create an HDR image, and the process will fail.

- Joe U.

[another view]

If you shoot with no exposure compensation and then increase exposure by two stops in your RAW converter, you'll have a different image than if you shot it at +2 (using +2 just as an example, but the more you adjust the greater the difference).

Just by that, I'd say that what you're describing is not the same thing as true HDR.