[Deefstes]

Hi all,

I'm taking a bold step here by making my official first post on Photocamel, yay! Actually, it's my fourth because I had to make three posts before I could post an image. So hello from sunny South Africa. I've had my DSLR for all of two weeks now so I still have lots to learn, not just of HDR but of photography in general.

Anyway, here is a HDR attempt that I shot over the weekend and my first real attempt at making a multi-image HDR. I used five images, keeping the aperture constant (f/5.6) and using five different shutter speeds (1/2, 1/4, 1/10, 1/20, 1/30) plus a tripod of course. All five images slapped into Photomatix and tweaked the settings a wee bit to get this result.


Your comments will be appreciated, and I'm more interested in "what I should've done different" than "why it's a nice picture"

Now I have some questions for the HDR gurus:

1. Getting different exposures. The way I see it there are four different ways to obtain different exposures.
   
   a. Keep everything constant but vary the aperture. I can understand why this is stupid as your depth of vield would differ from one exposure to the next.
   b. Vary the shutter speed (as I did with the image above). I'm using it because it's the only one that makes sense to me.
   c. Use auto bracketing. I'm not sure I really understand what auto bracketing does. Does it bracket your shutter speed, aperture, ISO setting or combination of shutter/aperture?
   d. Keep the shutter speed and aperture constant but vary the ISO setting. I've never tried this but my gut feel tells me it's a dumb idea.
   
   So the question, which method produces better results? Are there any other ways that I'm not aware of?
2. Number of exposures. How often would five exposures really be necessary? Of course this all depends on the dynamic range of the scene but realistically how often do you encounter a scene of which the dynamic range is bigger than what three shots at -2EV, 0, +2EV could capture? Am I correct in saying that, if you're using three shots, the following should be true in order to get a satisfactory HDR:
   
   a. The darkest parts of the scene should be sufficiently exposed in your underexposed shot.
   b. The brightest parts of the underexposed shot should overlap with the darkest parts of the normally exposed shot.
   c. The darkest parts of the overexposed shot should overlap with the brightest parts of the normally exposed shot.
   d. The brightest part of the scene should be sufficiently exposed in your overexposed shot.
   
   If a and d can be satisfied but not b and c, only then do you need more than 3 exposures. Or have I got it all wrong?
3. Photomatix or Photoshop? How often do you obtain satisfactory results using something like Photomatix and how often do you feel that you really need to exercise more control over the blending and do it yourself in Photoshop?
4. Other PP. Have you established a certain sequence of Post Processing that HDR images typicaly require? By looking at the most excellent shots that are often published in this forum, I get the impression that saturation is often pushed a little higher than normal (or is the world just that more colourful in your neck of the woods?)

Hope I didn't bore you to tears with all that but I'd love to learn a little more about HDR and how to get better results.