One thing you need to know before you shoot anything is what you want to use it
for.
If it's just for using the HDR image as a means of lighting (a low-res image is
enough) then the chrome ball
does the trick. Depending on the max resolution of your camera it might even be
high-res enough to be used as a reflection
map, depending on how close you get to the reflecting objects in your scene and
on how blurry the reflections are allowed to be (the blurrier the lower res the
HDR image may be to avoid visible artifacts/pixels).
Also, I found it helpful the use a tele lens when shooting the chrome ball. The
further away you are from the ball
the more info you get on the circumference of the ball, and the smaller your
own reflection will be in the resulting image.
If you absolutely need to avoid the reflection of yourself (and camera ) you
need to make two shots from different angles and paint yourself out later.
If you want to use the HDR image also as a background you will need extra high
resolution, and ideally no distortion.
However, affordable chrome balls are never distortion free, nor will you get
enough resolution from a single shot of the ball.
The only option I have found (besides using dedicated hardware like the spheron
camera) is shooting a panorama and stitching it into a really high-res image.
Any lens will do, but a fisheye will reduce the amount of images required and
time needed for a full panorama.
Shoot RAW if you can (or whatever floating point format your camera AND your
stitching software (or Photoshop) supports), image sequences of varying
exposure are more time consuming, and light can change fast while you shoot -
think wind and clouds on a sunny day, let alone the director getting nervous
while you fiddle around endlessly in between shots on a stressful day at -10 °C.
Hey guys -
I've been asked to help out on the show "Film Riot", and one of the things
we were discussing is creating your own HDR images.
I know HDRLabs has a ton of great info, but I was curious to know if anyone
else had any good info or resources on the subject that I could pass along.
It's not something I normally do, so I wanted to make sure I was giving
them up-to-date info.
Thanks,
Paul
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