Thanks, Toine! Jack
--- On Mon, 4/5/10, Toine <[email protected]> wrote: > From: Toine <[email protected]> > Subject: Re: Define "blown out" :-) > To: "Pentax-Discuss Mail List" <[email protected]> > Date: Monday, April 5, 2010, 1:02 PM > He did answer your question. Most > images have or should have blown out > parts (zone 9). > Some think it's something to avoid. I don't agree with > avoiding blown > out parts at all cost, even blown out parts in faces could > work. > Toine > > On 5 April 2010 21:44, Jack Davis <[email protected]> > wrote: > > I only read as far as about half of your first > sentence. I didn't need to read further as it was obvious > you had missed the point of the question. > > > > Jack > > > > --- On Mon, 4/5/10, Godfrey DiGiorgi <[email protected]> > wrote: > > > >> From: Godfrey DiGiorgi <[email protected]> > >> Subject: Re: Define "blown out" :-) > >> To: "Pentax-Discuss Mail List" <[email protected]> > >> Date: Monday, April 5, 2010, 12:05 PM > >> On Mon, Apr 5, 2010 at 10:27 AM, Jack > >> Davis <[email protected]> > >> wrote: > >> > I'll offer mine the nebulous term by saying > that if at > >> least some surface areas are rendered featureless > by virtue > >> of being too bright, I'd consider those areas > "blown out." > >> Many images can tolerate a certain amount of this > condition, > >> but it's amount is the criteria and varies with > each viewer. > >> Said areas must, of course, contain some available > mask > >> detail which defines the surface. > >> > IOW, I'm not talking about an absolute ball > of glare > >> wherein no detail is discernible. > >> > >> There's nothing nebulous about "blown out". > Consider areas > >> of pure > >> white with no detail as Zone 9 on the Zone System > >> scale defined as > >> follows: > >> > >> Zone 0 – key black or pure black – carbon or > photo > >> paper black. > >> Zone 1 – near black – shadows in faint light > or rooms > >> without light. > >> Zone 2 – dark gray/black – only subtle > textures are > >> visible. > >> Zone 3 – very dark gray – distinct shadow > texture is > >> visible. > >> Zone 4 – medium dark gray – slightly darker > “black” > >> skin, dark foliage > >> or shadows in landscapes. > >> Zone 5 – medium gray or 18% gray – darker > “white” > >> skin or lighter > >> “black skin,” light foliage or the dark blue > of a clear > >> blue sky. > >> Zone 6 – mid-tone gray – average “white” > skin or > >> shaded areas in snow > >> on a bright, sunlit day. > >> Zone 7 – light gray – pale “white” skin, a > concrete > >> walkway in sunlight. > >> Zone 8 – gray/white, near white – distinct > highlight > >> detail, like a > >> white wall in sunlight or brilliant surfaces in > flat > >> light. > >> Zone 9 – known as key white or pure white – > pure white > >> paper or snow > >> in bright sunlight. > >> > >> (Normally I think of the Zones as being from 1-10, > but > >> Ansel was a C > >> programmer and did a 0-based count ... ;-) > >> > >> So, by definition, anything you want detail in is > "blown > >> out" if your > >> exposure has placed it above Zone 8 on the above > scale. > >> > >> Since I've never seen any application use 16-bit > number > >> scales to > >> describe pixel values, you can determine what > areas of your > >> image are > >> "blown out" in Photoshop or Lightroom using either > a > >> percentage scale > >> or an 8-bit pixel value scale and floating the > cursor over > >> white-looking areas while looking at the > information > >> display panel. > >> Presuming that the exposure did not go to > saturation and > >> there is data > >> in those bright areas, you can place them in > adjustment > >> using the > >> Exposure (aka white point) sliders. This table > makes it > >> easy ... > >> > >> http://homepage.mac.com/godders/zone-system-numbers.jpg > >> > >> EG: you have a near blown out area in a photo that > you want > >> to ensure > >> images with detail on screen and in your prints. > Float the > >> cursor over > >> it in Lightroom and see that it is currently at > about 94% > >> in all > >> channels (or in one of them if that is the > significant > >> color of the > >> area). Nudge the Exposure slider in the negative > direction > >> until it is > >> in the range of about 85-88% to set that as the > brightest > >> point. Now > >> make adjustments with the mid-tone, black point > and Tone > >> Panel to > >> bring the rest of the photo into line with a > satisfactory > >> display. > >> > >> A certain amount of area at Zone 9 is fine, as > long as it's > >> not where > >> you wanted to convey detail. Too much Zone 9 in an > image > >> generally > >> looks bad. Another thing to be aware of is that > many papers > >> and > >> monitor screens cannot display the full 10 zone > scale very > >> well, or > >> have non-linear characteristics ... That's why > calibration, > >> profiling > >> and testing for DR are essential to good quality > image > >> display, > >> whether on screen or on paper. > >> -- > >> Godfrey > >> godfreydigiorgi.posterous.com > >> > >> -- > >> PDML Pentax-Discuss Mail List > >> [email protected] > >> http://pdml.net/mailman/listinfo/pdml_pdml.net > >> to UNSUBSCRIBE from the PDML, please visit the > link > >> directly above and follow the directions. > >> > > > > > > > > > > -- > > PDML Pentax-Discuss Mail List > > [email protected] > > http://pdml.net/mailman/listinfo/pdml_pdml.net > > to UNSUBSCRIBE from the PDML, please visit the link > directly above and follow the directions. > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link > directly above and follow the directions. > -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
