Comparison of 4-Shot vs 14-Shot HDR

[Ken-L]

First I selected 4 shots from the 14 to be processed in batch mode by Photomatx with no changes to its settings.
I then processed the resulting images first with Irfanview to simply re-seze to 800 pixels wide, and then with Photoshop CS3 using only its AUTO: Exposure, Levels, Contrast, Color, and Curves functions. No other adjustments were made.

On my calibrated monitor I can see the subtle differences between the images.....
It appears to me that the 14-shot versions are "smoother" with more subtle tones. The differences, while not very great are substantial. Perhaps other examples might produce differing results.....but for now, where and when I can use larger numbers of shots to process in HDR I will do so.

Here are the two, in two sets. First are the images created by Photomatix and resized for this post, and then those images processed in PSCS3:

4-Shot Version

14-Shot Version

4-Shot Version after PP

14-Shot Version after PP

[Jason Hermann]

At this resolution the difference is negligible. As you will come to see that certain situations require more frames. As long as you have all the dynamic range in the scene 1 photo in theory is enough. But usually 3 photos will do it either a stop apart or 2 stops apart depending on the dynamic range in a given scene.

Moving water I notice can sometimes require more than 3 frames even if all the DR is captured. This is a problem that photomatix has when rendering the flowing water. Depending on the shutter speeds of the given frames the info for the water might be missing in some of the rapids. What happens is you will get a weird artifact like gray blotch sometimes. I haven't been able to nail down what shutter speed this happens at, but it seems to depend on the amount of rapids in the water in combination with shutter speeds

On another note, I don't see any reason to take 14 frames for a shot like your image above. The more frames the more chance for noise, dust showing up, camera movement, ect... 6 would be more than enough I would think.

Keep up the great work Ken and please keep sharing your insight!! I'd love to hear your thoughts as you learn this new frontier of HDR

Best,
Jay

[Ken-L]

Originally Posted by Worm324

........................
Moving water I notice can sometimes require more than 3 frames even if all the DR is captured. This is a problem that photomatix has when rendering the flowing water. Depending on the shutter speeds of the given frames the info for the water might be missing in some of the rapids. What happens is you will get a weird artifact like gray blotch sometimes. I haven't been able to nail down what shutter speed this happens at, but it seems to depend on the amount of rapids in the water in combination with shutter speeds

.....................
Keep up the great work Ken and please keep sharing your insight!! I'd love to hear your thoughts as you learn this new frontier of HDR

Best,
Jay

Thanks Jay!

Moving water can present a lot of problems when taking several images.....if Photomatix has a hard time dealing with it I can understand that! Maybe if you turn off the automatic alignment feature....Photomatix may not be able to "align" moving water to the point that it just gives up.....

For moving clouds I would want to take only three shots as fast as possible....although I managed 14 and my clouds were moving slowly enough that there wasn't a problem.

When I take a shot of the bay or a lake at night with a very long exposure it evens the surface so that it looks like glass, so these would only be helped by a number os shots with slow exposures.