| my 2ct: | | - underexposure + digital exposure correction is terrible wrt noise
This is apparently potentially camera dependent. Some recent cameras have had noise profiles such that *for noise* it didn't matter what ISO you shot at; underexposure and then bringing the exposure up in post-processing got you the same noise results as exposing at the 'proper' high ISO. When I saw the discussion, the jargon term for such cameras was 'ISOless' and the example was the Nikon D7000. Using artificially low ISOs in such a camera can be potentially useful to preserve highlights in scenes with high dynamic range, such as night time scenes with artificial lights. (If people want to read a lot about this and noise issues in general, see eg http://www.dpreview.com/forums/post/37590422 and http://www.dpreview.com/forums/thread/2903658 among others.) There is also a second issue: above a certain high ISO most cameras stop increasing the analog-to-digital converter gain (ie, really increasing 'ISO') and just multiply the numbers the ADC is producing before they write the RAW. From an image quality perspective this makes really high ISOs pointless (they contain neither better data nor new data; all they do is potentially clip more and more highlight data). In practice, I expect most people can just ignore all of this. Certainly I mostly do; I consider the technical details interesting but they don't particularly affect my shooting and I've done nothing to really find out the limits of my particular DSLR. In real life it's just easier to let the camera meter and expose things 'properly', even if it involves a high ISO. (I did do enough reading to see that my current DSLR is not ISOless due to pattern noise in (some) dark shadows. This handily validates my lazy 'let the camera metering do what it wants' approach.) - cks ------------------------------------------------------------------------------ How ServiceNow helps IT people transform IT departments: 1. A cloud service to automate IT design, transition and operations 2. Dashboards that offer high-level views of enterprise services 3. A single system of record for all IT processes http://p.sf.net/sfu/servicenow-d2d-j _______________________________________________ Darktable-users mailing list Darktable-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/darktable-users
