Need Photoshop help! High Dynamicy Range?

Question

I'm very confused about a photo assignment. Here are the instructions that I don't understand:

1) Shoot 5 bracketed images in your camera's RAW (16 bit) file format.
2) Open bridge and select images to use. Tools/Photoshop/Merge to HDR (High Dynamicy Range).
3) Single HDR image will open in Photoshop (looks like any other image but is in 32 bits and has wider density range). Save image right away in PBM (portable bitmapped) format.
4) Convert image to 16-bit mode so you can have the full range of adjustments available.

That's just the first half. I have no idea what that means. Can anyone interpret it?? I feel dumb.

Answer 1

The dynamic range of a photograph tells you the difference between the brightest white and the darkest black that could be represented by the file format and camera sensor. Digital camera sensors have a dynamic range that is inferior to human vision. To make up for this, a technique has been invented called high dynamic range. To do this, the same picture is taken several times, but at slightly different exposure settings (different times). The shorter exposures get the details in the bright areas. The longer exposures get the details in the dark areas. The "correct" exposure gets the details in most of the image. A computer program is used to put these low dynamic ranges images together into one, bit image with a higher dynamic range. More images at more settings allow an even higher dynamic range. Now, I'll answer your question:

1. Mount your camera in place so it won't move when you adjust it. Hopefully you have a sturdy tripod for this. Read your camera's manual to find out how to save pictures in RAW format instead of JPEG. After taking the picture, take one over more time, and a third over even more time. Then take one at a shorter time, and a fifth one over an even shorter time. Look in your camera's manual if you don't know how to do this.

2. Copy the files to your computer. Use your photo editing program to put the pictures together into one picture.

3. Save the image in a file format that can handle the extra range. JPEG isn't up to the task and RAW is camera specific.

4. This should also be in your photo editing program.

Answer 2

Read this one first to get an idea what it's all about:

http://www.popphoto.com/popularphotographyfeatures/3970/how-to-make-hdr-images.html



This one is specific for Photoshop:

http://www.popphoto.com/popularphotographyfeatures/4117/high-dynamic-range-imaging-with-adobe-photoshop-cs3.html



Info about a new program fro HDR:

http://www.popphoto.com/popularphotographyfeatures/4472/hdr-how-to-dynamic-photo-hdr.html

Answer 3

All you have to do is use the Merge to HDR tool File > Automate > Merge to HDR to combine your OE, NE and UE image files

Answer 4

simply put here ...http://www.dpreview.com/learn/?/Glossary/Digital_Imaging/dynamic_range_01.htm