[Radiance-general] Digital Camera recommendations?

[Kirk Thibault]

Great tips!  I would also add that in addition to a remote camera 
trigger (computer or camera-specific remote) you typically can also use 
the timer function on cameras so equipped.  My camera, a Canon 300D 
("Digital Rebel"), shoots 3 auto bracketed exposures from a single 
timer triggered event.  This way you can change your exposure via the 
shutter speed, set the AEB to +/-1 and then hit the shutter release, 
run out of the mirror ball environment and the camera will shoot all 
three AEB images.  This is particularly useful for settings where 
lugging a laptop may be a pain, and it also allows you to get out of 
the scene.

Also, i usually shoot overlapping exposures throughout the sequence and 
then compare the exposures that have identical settings to make sure 
that the light conditions were not changing significantly while 
shooting the mirror ball.  Otherwise, the recorded exposure and the 
actual exposure may differ - although I don't really know how 
significant this effect may be.  Obviously this would be more for 
natural light sources like the sun behind clouds, etc.  I usually shoot 
about 7 or 8 exposures worth of info and use HDRShop or Photosphere to 
make the images.  Tripod is a must and white balance setting would 
probably also be helpful so it does not change while shooting.

Have fun - I'm sure there are already several compact point and shoot 
type digital cameras out there that are already better than my digital 
SLR - for what it's worth, I have seen price drops on the 300D that are 
coming close to your ball park for a camera, if you are entertaining 
the notion of a digital SLR - I would highly recommend this camera to 
amateur digital camera users.  Good luck!

kirk

On Mar 9, 2005, at 9:23 AM, Despina Michael wrote:

> Hi Rob,
>
> I have create a couple of HDR probes lately and I can tell you what 
> settings I have used.
>
> First of all, the sequence of photos that you have to take must be 
> perfectly alighned.
> The only way that works for me to do that, is to place the camera on a 
> tripod and take photos remotely (that is connect the camera with a 
> computer and use remotly capturing pressing a key on the keyboard - 
> camera's software should have the appropriate software for that - but 
> good cameras usually do have)
>
> I don't think so, auto bracketing is a good idea. Most cameras can 
> take about 3 (or 5) photos with Auto Bracketing but you need more in 
> order to create an HDR Probe (about10-15 photos)
>
> In order to take the photos set aperture at a fix value and change 
> only exposure time in order to change the overall exposure.
> You also have to set your camera at no flash.
>
> You should  take a sequence of photos (about 10-15) with different 
> exposure times, changing 1 f-stop each time, starting with bigger 
> exposure.
> Before begin to take your photos, take one photo using auto-focus in 
> order camera focus on the mirrored ball. Then set manual-focus and 
> don't change focusing (that is in order to have all photos with same 
> "focus value")
>
> If you planning ton use hdrgen for generating HDR probe, I recommned 
> you to disable alignment algorithm. At least in my case, when 
> alignment was enable hdrgen gave worst results.
>
> I hope it helps,
> Regards,
> Despina