On 6/26/2015 6:34 PM, C.H.Ling wrote:
----- Original Message ----- From: "Moose" <olymoose@xxxxxxxxx>
You are certainly correct that Oly is cropping the post correction image
(and ACR is obviously using the same exact
algorithms). However, I don't see where they would be up-sampling.
I suspect the whole image is enlarged in the
correction process (why?), then simply cropped to size.
At the long end of 12-40 Olympus RAW gives similar AOV as RawTherapee
so there must be different cropping on different focal length in Olympus
RAW. If different cropping is using on different focal length and Olympus
has to keep same pixel dimension on its files then they has to up-sample
the image.
UNLESS - Oly's process of linear distortion correction in itself enlarges the image, the greater the barrel distortion,
the greater the enlargement. So at the long end, where pincushion is more likely, there would be little or no
enlargement from the correction process.
At the same PPI, the objects on the image of Olympus one is bigger. As I
don't think RawTherapee will down-sample the image then it must be Olympus
up-sample it. No matter the up-sample is done during distortion correction
process or after, it has the same effect.
Agreed. And it's wrong, throwing away that much of the WA on has paid for.
It's good to be aware, as I can use DxO when I need it. OTOH, I don't think it much effects me, personally. As I
discovered when looking for an example, I don't shoot at 12 mm very often, and with most of those, the small loss
doesn't matter. 12 mm isn't wide enough for any broad landscapes. I'm usually carrying the tiny 9-18, and even that is
mostly not wide enough for that, so I shoot stitched panoramas.
Very wide lenses are, for me, mostly about close quarters.
The panorama I posted a couple of days ago was WAY too wide for any single lens. And those I tend to shoot at longer
focal lengths, for the different perspective/look and lack of distortion. That one was shot at 50 mm (100 mm eq.)
Shaved Vision Moose
--
What if the Hokey Pokey *IS* what it's all about?
--
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/
|