Yes, this is another an illustration of the advantages of RAW files. Also, the lower bit depth of JPEGs may have an influence here: maybe a little more details could have been recovered from the highlights if the original image had been a RAW or a TIFF.
But now that I think of it more closely, I understand that JohnPW's question is still unanswered and that my answers completely missed the point. I expect the faux-bracketing to keep the lightest parts of the darkest exposure and the darkest parts of the lightest exposure. If this were true, there should not be any loss in the highlights. Obviously enfuse decided otherwise, but why did he do so and is there any way to make him behave as I expect? 2012/12/19, Gnome Nomad <[email protected]>: > All CCDs have limits to how bright or dark a value they can record. RAW > formats can allow software to recover blown highlights to an extent, but > it's really more of an educated guess based on surrounding pixels. > > When the sensor in my Maxxum 7D blows a highlight, it's really blown, > and unrecoverable. Other sensors, such as the ones Canon uses in their > lower-end DSLRs, don't blow highlights as quickly as my camera does. But > they will all blow highlights sometime. > > That's why true HDR shoots sets of images with a range of exposure > settings. One's exposure is set so the blackest blacks fall within the > camera's dynamic range. The lightest exposure is set so the brightest > whites fall within that dynamic range. (I've shot HDR sets with about 9 > stops exposure). Bracketing is just an automatic, less flexible way of > doing that. Faux bracketing doesn't have the same dynamic range > available to start with, although it can work out effectively where you > have a contrasty scene but want to pull detail from both the bright and > dark portions of the image. > > Or something like that. I'm tired! #-/ > > On 12/18/2012 12:43 PM, JohnPW wrote: >> Sure, in fact I have the camera default set to underexpose by .75 stop >> (which is probably the only thing you can do if you can't shoot RAW.) >> But the fact that the detail exist in o1 shows that the detail is lost >> in the transformation, not because of the camera. >> >> On Tuesday, December 18, 2012 4:34:30 PM UTC-6, Frederic Da Vitoria >> wrote: >> >> Yes, you are right, I didn't look closely enough. The details in the >> T shirt are more immediately visible, but the textures in the >> lightest zones now seem uniformly white. In my experience, P&S >> cameras have a tendency to over-expose pictures. Maybe choosing >> picture with a better exposition (that is under-exposed by the >> camera's standards) would give better results. >> >> 2012/12/18 JohnPW <[email protected]> >> >> Are you sure you didn't mix the two up? >> o1 is the original and o2 is the output. >> In my opinion the shirt detail in o2 is very clearly blown out >> compared to o1. >> BTW, I agree that it's best to compare o1 and o2. I >> included c100 to show that at least one of the intermediate >> image isn't blown out at Bugbear wondered. >> >> >> On Tuesday, December 18, 2012 3:37:17 PM UTC-6, Frederic Da >> Vitoria wrote: >> >> Hello JohnPW >> >> IMO, you shouldn't compare the highlights between any image >> and c100: since c100 is the darkest, it will always show >> more details in the highlights than any other picture. You >> should always compare with the original. Does o2 do better >> than à1 in the T shirt? I believe so. > > > -- > Gnome Nomad > [email protected] > wandering the landscape of god > http://www.clanjones.org/david/ > http://dancing-treefrog.deviantart.com/ > http://www.cafepress.com/otherend/ > > -- > You received this message because you are subscribed to the Google Groups > "Hugin and other free panoramic software" group. > A list of frequently asked questions is available at: > http://wiki.panotools.org/Hugin_FAQ > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/hugin-ptx > -- Frederic Da Vitoria (davitof) Membre de l'April - « promouvoir et défendre le logiciel libre » - http://www.april.org -- You received this message because you are subscribed to the Google Groups "Hugin and other free panoramic software" group. A list of frequently asked questions is available at: http://wiki.panotools.org/Hugin_FAQ To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/hugin-ptx
