Archived posting to the Leica Users Group, 2009/05/04
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 05:16 PM 5/4/2009, you wrote: >Tina we shall have to call you the LUG Geek chick! This is certainly very >interesting. I have not tried this at all. I don't understand how this can >extract more information from your neg compared to a flatter scan as long as >that scan is not clipped at either end? Is it just because using the HDR >software is much more convenient? >Can anyone educate me? >Point me to a good tutorial on-line? Here is one explanation I found: "The dynamic range of your film is usually greater than the dynamic range that the CCD in your scanner can capture at a given exposure time. When scanning the film multiple times with different exposure times (longer exposures to resolve details in the shadows, shorter for more details in the highlights), you can extend the dynamic range by blending the resulting scans." And from Photomatix: (Refers to one exposure, but you can use the same technique with several scans. I use #3.) "Yes, you can still use Photomatix when you have shot only one exposure in RAW mode. The big advantage, of course, is that you just need one image, so there is no need to use a tripod or to remember to auto-bracket, and it will also work if the subject is moving. However, the range of "workable" exposures you can get from a RAW file is limited. If you are shooting a high contrast scene, you are unlikely to match the results you would have with taking the scene under different exposures that can cover the whole dynamic range. There are three techniques for using Photomatix with one single exposure taken in RAW mode: ? Technique 1: Open your RAW file in Photomatix to convert it into a pseudo-HDR image, then tone map it. ? Technique 2: Convert your RAW file into a 16 bits/channel image in your favorite RAW converter, open it in Photomatix, and tone map it. ? Technique 3: Create two or three exposures in your RAW converter and combine them in Photomatix as it they were "real" bracketed shots Technique # 3 gives generally the best results. Also, it has the advantage of working with Exposure Blending. " There's lots more information on the Photomatix site: http://www.hdrsoft.com/support/faq_photomatix.html#tips And a list of good tutorials here: http://www.hdrsoft.com/resources/index.html Hope this helps. I'm really having fun playing with HDR and negatives. Tina Tina Manley www.tinamanley.com