[Leica] About to take M8 plunge - but worried about blownhighlights...

[henningw at archiphoto.com (Henning Wulff)]

>Henning, you are of course correct on sensor characteristics. Nevertheless I
>do not see this effect around highlights with my M8 and current Leica glass.
>It is sometimes noticeable in photos from some Canon or Nikon DSLRs (as well
>as other differences naturally). I recall too, being shown the effect here
>in this group with longer teles in use and recorded on transparency film.
>APO design does contribute to the quality of photos with short teles for
>M's, without question as well.
>Would you care to share your views on the practice of routine negative EV
>compensation vs. 'exposing to the right"?
>
>Cheers
>Geoff
>http://www.pbase.com/hoppyman/e
>http://gallery.leica-users.org/v/gh/
>-----Original Message-----
>Subject: RE: [Leica] About to take M8 plunge - but worried about
>blownhighlights...
>
>At 12:46 PM +1000 9/3/08, Geoff Hopkinson wrote:
>>Hi Simon, there is very sound advice in the thread, as you would have
>>already seen.
>>Some additional comments from me on technique for the situation you
>>describe.
>>Firstly the chromatic aberration you mention is very likely from the lenses
>>used. Another great reason to have superb Leica glass!
>
>
>Actually, the 'chromatic' issues around highlights are not a function
>of the lens, but of the sensor and the light qualities that hit it.
>
>Highlight blowout is due to sensor saturation, ie, the sensor cannot
>register the actual number of photons that have hit it as it's a
>number that's bigger than what it's maximum. Near the actual
>highlight, where every channel is blown out, is a region where some
>channels are saturated, but not other(s). That will give areas or
>rings around the highlights of colours that have not yet saturated.
>Because some channels have saturated in this region, the colours will
>be false as the saturated channels cannot provide the proper value.
>
>All digital sensors will do this, but unless the highlight areas are
>large with gradual transition areas, it won't be a problem. There are
>some workarounds, but they involve 'creating' some colour values in
>this region.
>
>--
>     *            Henning J. Wulff
>    /|\      Wulff Photography & Design
>   /###\   mailto:henningw@archiphoto.com
>   |[ ]|     http://www.archiphoto.com
>
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>
>
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-- 
    *            Henning J. Wulff
   /|\      Wulff Photography & Design
  /###\   mailto:henningw@archiphoto.com
  |[ ]|     http://www.archiphoto.com