> > Posted by Terry McDonald (Luxborealis) on Sunday, January 07, > > 2007 - 4:49 pm: > > I'm curious - in the conversion from ORF to DNG how can the file > size > be reduced to one-half without losing any quality? That's a huge > savings. Are Olympus engineers missing something? > > Also, are you doing any tweaking in ACR before converting to a DNG? > > --Terry
The size of RAW ORFs from my E-500 is about 14 megs. After converting to DNGs the size is reduced to about 7 megs. I am not knowledgeable about how the reduction in size is made (I'm sure others will be able to explain it), but there does not appear to be any loss of quality from the original ORF to the converted DNG.
I do not bring the converted DNG into ACR. I use Lightroom instead and import the DNG directly into Lightroom. Lightroom offers many more options for tweaking the raw DNG compared to ACR. After applying some of those tweaks, I then edit the file in either Paint Shop Pro or Photoshop, depending on what I believe needs to be done to that file. (If I edit it in PS, I always convert it to Lab and do my editing in Lab following the techniques discussed in Margulis' book.)
Herb