[Leica] Auto HDR -- is nobody paying attention?

[hoppyman at bigpond.net.au (Geoff Hopkinson)]

Henning has it nailed as usual. Write 'dynamic range' inside your camera
bag. Right next to 'light, eyes, content'.
Don't throw away any of those highlight values when you expose.
Plus if one or two channels still have information your raw convertor may be
able to reconstruct the missing information. Don't forget that the shadow
end of the file (noise and shadows tones) is greatly affected by the total
(linear) tonal range that you start with.
Remember that your camera histogram is based on the squashed down jpg
version of your exposure too. Clipped ain't always clipped. Nearly clipped
is nirvana. Try it out for yourself.

Cheers
Geoff
http://www.pbase.com/hoppyman/e
http://gallery.leica-users.org/v/gh/

-----Original Message-----
Subject: RE: [Leica] Auto HDR -- is nobody paying attention?

At 12:32 PM -0400 4/24/08, wildlightphoto@earthlink.net wrote:
>Kyle Cassidy <kcassidy@asc.upenn.edu> wrote:
>
>>  Light comes through the lens, hits the sensor. As soon as values reach
>>  254 the camera should save a file at that exposure which can then be
>>  merged (if necessary) with the master file so that burned highlights can
>>  be salvaged.
>
>Or with 16-bit pixels, 65534 instead of 254.



The limiting factor is dynamic range, not number of bits. The Fuji S5 
addresses that to a limited degree, but not to HDR standards.

With present sensors and photon acquisition methods it's hard to get 
real time greater dynamic range. One possibility might be to actually 
do two exposures during the nominal exposure time. Exposure time 
would then take on a new meaning, and this clearly wouldn't work when 
you need an extremely short exposure, but it should be doable when 
you only need 1/125sec.


-- 
    *            Henning J. Wulff
   /|\      Wulff Photography & Design
  /###\   mailto:henningw@archiphoto.com
  |[ ]|     http://www.archiphoto.com

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