I believe the in camera histogram is taken from the jpeg thumbnail. graywolf http://www.graywolfphoto.com http://webpages.charter.net/graywolf "Idiot Proof" <==> "Expert Proof" -----------------------------------
Stan Halpin wrote: > The manual that came with my wife's D-Lux3 explicitly stated that one > should not expect the on-camera histogram to agree with a histogram > in any post-processing software. > To ease the processing load, I would guess that the on-camera > histogram is a rough approximation taken by extrapolation from a few > sampled pixels strategically spotted around the sensor coverage. > This is a familiar strategy to me - I sometimes ease processing load > by providing opinions that are a rough approximation based on > extrapolation from a few data points. > > stan > > On Jun 17, 2007, at 11:24 AM, Bob W wrote: > >> A Royal Navy carrier (Ark Royal, according to the sailors' hats) is in >> Greenwich today, so I decided to take a picture of it. It's a rather >> uninteresting picture, but given the very grey tonality I thought I'd >> play around with exposing to the right to see what difference it made >> in Lightroom when I applied a tone curve. I first made an exposure on >> auto with no compensation, and looked at the histogram. I then dialled >> in various amounts of over-exposure to move it to the right until the >> histogram fell off the edge. >> >> To my surprise, when I look at the pictures in Lightroom the histogram >> is significantly further to the right than it is on the camera's >> display. So the exposure that was right up against the edge in the >> camera, has fallen over it in Lightroom. Is this normal? Have other >> people seen the same thing with their cameras? >> >> Here is a photo that was over to the right, but not quite at the far >> end. About +1.5 stops, I think. >> http://www.web-options.com/Carrier/content/_6175495_large.html >> >> Architectural note: you can see the dome of St. Paul's towards the >> bottom right - it's about 5 miles away. >> >> Regards >> Bob >> >> >> -- >> PDML Pentax-Discuss Mail List >> [email protected] >> http://pdml.net/mailman/listinfo/pdml_pdml.net > > -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
