Archived posting to the Leica Users Group, 2015/01/16
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]My contribution was just about how deceitful usual (mis)conceptions of ISO are Mark. Hope they could help you a bit as they did me. Amities Auto everything Philippe Le 15 janv. 15 ? 17:20, Mark Rabiner a ?crit : > Thanks Philippe I look this up and the all see this is relevant more > for > Canons than Nikons at this point. And not just Sony's or Fuji's. > I'm not > looking forward to shooting with near dark LCD screens to not be > able to > see. I think when this approach is viable we'll able to see what > we're > doing in the back of the camera like we always have been able to see. > I still have my Nikon D700 set at Auto ISO and will hopefully not > find out > that I've been doing it wrong for 5 years and more. I'd be amazed to > see > that. We had a guy on the LUG doing that last month I had mixed > feelings > about his whole mind set. > I guess more of a chance of this relating to my next camera. > Which would be a Nikon D760. As they are pulling the 750's off the > shelves. > > The Nikon 750 sensor debacle kind of lines up with the Leica CCD > sensor > corrosion scandal. Just in time for 2015. > We are still working out basic bugs in this whole digital thing. > > > On 1/15/15 5:14 AM, "Philippe Amard" <philippe.amard at sfr.fr> wrote: > >> >> Le 15 janv. 15 ? 10:09, Mark Rabiner a ?crit : >> >>> I'm not sure if we have a real >>> sense of what iso we can use it at now?!? >> >> >> This might help add to our confusion circle ;-) >> >> >> DR Modes and the ISOless APS-C Sensor >> >> You may have heard that Fuji?s APS-C cameras are all based on modern >> ?ISOless? Sony sensors. These sensors are used by several leading >> camera manufacturers, such as Sony (of course!), Nikon, Ricoh/Pentax, >> Leica and Fujifilm. >> >> The ?killer feature? of ISOless sensors is their ability to rely on >> digital gain (as opposed to analog amplification) for the most part >> of >> their operation. Digital gain can be applied anytime during your >> workflow?before and after the RAW file has been created. As a matter >> of fact, it?s better to apply digital gain after the fact?when the >> RAW >> in processed in a converter. This is also the reason why Fujifilm >> RAWs >> don?t go beyond ISO 1600. They remain the same?any further gain >> between ISO 1600 and ISO 6400 is applied digitally during RAW >> conversion. >> >> This means that in high-ISO scenarios, achieving ?perfect exposure? >> before you press the shutter button doesn?t really matter. You can >> just as well change the exposure later in the RAW processing phase? >> either in-camera, or with Lightroom (or with another RAW converter) >> in >> the comfort of your home. Click here to read a forum thread with a >> demonstration of this feature. >> >> Between base ISO 200 and ISO 1600, ?mixed? analog/digital >> amplification maintains a slight quality advantage over ?pure? >> digital >> gain. That?s why your camera is still using at least some analog >> signal amplification up to ISO 1600. Enabling the DR function >> basically switches the mixed analog/digital process over to a pure >> digital gain (or tone-mapping) process for either one (DR200%) or two >> (DR400%) analog signal amplification stops. >> >> Let me give you an example: Shooting an image at ISO 800, DR100% will >> result in an ISO 800 RAW file that?s based on an ISO 200 exposure >> with >> two stops of mixed analog/digital amplification/gain. Shooting the >> same image at ISO 800, DR400% will result in an ISO 200 RAW file with >> digital tone-mapping being applied during RAW conversion. This tone- >> mapping is pushing the result to ISO 800 in the shadows and midtones, >> while retaining bright highlights at ISO 200. You would have a hard >> time telling the ?analog? from the ?digital? ISO 800 result when >> looking at the shadows and midtones. You will however recognize that >> the digitally processed DR400% version offers two additional stops of >> highlight dynamic range. This is exactly what we want when shooting >> scenes with high DR, like christmas markets with festive lights and >> very strong contrasts. >> >> In other words: Yes, sensors have a fixed dynamic range, but the >> actual dynamic range that can fit into your actual image file is not >> just determined by the sensor, but by the signal processing and by >> whatever happens during RAW processing. By applying ?adaptive ISO? >> during RAW processing, you can expand the actual dynamic range of any >> image by 1, 2, 3 or even more stops. The sky?s the limit, but for >> practical reasons, there will always be quality considerations, since >> the application of digital gain results in a similar image >> degradation >> as raising ISO values the old-fashioned way. >> >> >> >> >> >> Much more at : http://www.fujirumors.com/exposing-right/ >> >> Amities >> >> Ph >> >> >> >> >> >> >> >> One sees clearly only with the heart. What is essential is invisible >> to the eye. Antoine de Saint Exup?ry in Le Petit Prince. >> NO ARCHIVE >> >> >> >> >> >> _______________________________________________ >> Leica Users Group. >> See http://leica-users.org/mailman/listinfo/lug for more information > > > > > -- > Mark William Rabiner > Photographer > http://gallery.leica-users.org/v/lugalrabs/ > > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information One sees clearly only with the heart. What is essential is invisible to the eye. Antoine de Saint Exup?ry in Le Petit Prince. NO ARCHIVE