3 Exposure HDR As Real As I Could Make It

[canonloader]

Here's the original from the properly exposed RAW, no post processing, no noise removal, no sharpening. Just convert to JPG and resize.

http://www.picturelacrosse.com/hdr/river/rootwad-set1-img_3219-100308.jpg

Here's the HDR from the 1 2/3 over, 1 2/3 under and neutral RAW shots, no noise removal, no sharpening, and it actually took very little tweaking in CS3 or PM...
http://www.picturelacrosse.com/hdr/river/rootwad-set1-img_3218-100308.jpg

[Duder]

it's looks like you've recovered some detail in the highlights, but the deep shadows still look burnt out, and overall the dynamic range doesn't look much greater than the single exposure.

[luigis]

Agree with Pete the scene is probably not very good for HDR because it SEEMS that the dynamic range of the camera would be enough for the range in the scene.

Luigi

[canonloader]

I see what you mean, but I think it is close to what our eye can see. I know it's much better than film or a sensor, but it's not perfect. I don't think the eye can see detail in that shadow under the log, for instance, but the bark in the two big trees shows a lot more detail. But what really got me, was the CPL effect of being able to see into the water. :)

[Duder]

I meant the dynamic range in both images looks much the same. Sunny days are perfect candidates for HDR because the dynamic range is greater between the brightest and darkest points, which is why bracketed exposures are needed to capture the detail that a single shot wouldn't be capable of.

[canonloader]

Well, the HDR shot is bracketted at +/- 1 2/3 stops and zero. The single shot is the one at zero.

[Bill Pham]

i don't know if the second one is better. there is something not right about it. but i like that one more than the first one. seem closer to the real thing.

Bill

[luigis]

How's the histogram of the zero shot?

Well, the HDR shot is bracketted at +/- 1 2/3 stops and zero. The single shot is the one at zero.

[canonloader]

I liked it cause it doesn't have the HDR overcooked look to it, to me, anyway. Just nice to know it can be done. :)

[canonloader]

How's the histogram of the zero shot?
It's mostly to the left. At least the one that CS3 shows for it.

[luigis]

Does it touch the left part?
If the histogram is leaned towards the left and it doesn't have blown highlights you can try the same HDR but with -1 +1 and +3 instead of -2 0 and +2. That will probably get the detail from the shadows better and have a more realistic look.

It's mostly to the left. At least the one that CS3 shows for it.

[canonloader]

It's so close to the left that it almost touches. It's piled up that way, but drops off just before hitting the left edge. I use to shoot these in AV Mode and use the wheel to set exposure compensation instead of setting shutter speed. Sometimes that worked better. :)

[luigis]

In AV mode overexpose +1 if the histogram seems to be leaned to the left. The basic idea for an HDR is that in the overexposed shot you don't want anything touching the left side of the histogram and in the underexposed shot you don't want anything touching the right side of the histogram.

[Duder]

+/- 1 2/3 stops probably isn't enough for a harshly lit scene. you'd probably need an extra exposure to capture the deep shadow detail.

[canonloader]

So I should be watching the histogram no matter what, not just taking +/- exposures, even if they are piled up against the sides? That makes sense. No data in a shot if it's piled up against the sides anyway, right?

[Duder]

yeah, keep an eye on the histograms, but if you really want to get good shadow detail you might be better firing off an extra exposure or two, pushing the histogram far to the right.

[canonloader]

I'm glad I posted this, cause I have had my eyes opened about how to shoot. I was just going along fat, dumb and happy, shooting 1 stop spreads from 2 or 3 under to 2 or 3 over and not even thinking of the histogram. :lol:

I also just snapped to the fact that while the 40D shows +/- 2 only, you can get far more out of it by just using shutter speeds. Duhhhh.... ;)

[Duder]

well, the ol' triple auto-bracketed exposures +/-2EV's works well for most scenes, but not all.

[canonloader]

Yeah, I was using that pretty regularly, then read somewhere that recommended 1 2/3 instead of 2, for some arcane reason. Maybe it's the power of suggestion, but it seems to work a little better. 1/3rd stop isn't that much difference. :)

[luigis]

The most normal "workflow" is to take a bracketed shot centered at zero then you check the -2 and +2 exposures if the histogram doesn't touch the right side on the underexposed shot and it if it doesn't touch the left side on the overexposed shot then you are fine because your 3 RAWs have captured the dynamic range of the scene.
If not then you usually take some extra underexposed or overexposed shots as needed.

My experience is that 3 shots are fine for 70% of the scenes.
My record is 24 exposures inside a tunnel because the tunnel was totally dark but the end was totally bright with the noon sun.
At night you usually need an extra overexposed shot or two because the shadows generate noise and the tonemapping multiplies the noise in the image.

Luigi

[canonloader]

How do you take 24 shots? I mean, what do you do? Shoot in manual? 1/3 stops, 1/2 stops, 1 or 2 stops? And computed how, by shutter speed? Some would almost need to be in the second or two range.

[Duder]

the easy way to do it is, start with the highlights - shoot the first photo to cover the brightest parts of the scene - then keep taking photos, dropping down the shutter speed 2 stops at a time until the very darkest shadows have good quality detail in them. It might take you 3 or 4 photos, or it might take 10 or 12.