That's really interesting, I guess the correction for linear distortion
followed by the necessary crop explains it.
What is the difference between the out of camera JPG and the converted
images ?
Is the angle of view different on the screen prior to shooting compared with
viewing the shot image ?
I presume the lens corrections wouldn't been done at the liveview stage.
...Wayne
-----Original Message-----
From: olympus
[mailto:olympus-bounces+wayne.harridge=structuregraphs.com@xxxxxxxxxxxxxxxxx
] On Behalf Of C.H.Ling
Sent: Saturday, 20 June 2015 4:45 PM
To: Olympus Camera Discussion
Subject: [OM] Olympus 12mm is not 12mm?
Just found an interesting issue with the lens angle of view on the newer vs
older M4/3 bodies and also Viewer 3 vs RawTherapee.
Following two images are RAW converted on Viewer 3
EP-5 with 12-40mm at 12mm:
http://www.accura.com.hk/temp/P6172303-OV3.jpg
E-PL1 with the same lens at 12mm on a different day:
http://www.accura.com.hk/temp/P6200387-OV3.jpg
You can see the shot from E-PL1 cover a wider angle.
Following two images are same as above but converted with RawTherapee.
E-P5:
http://www.accura.com.hk/temp/P6172303-RT.jpg
E-PL1:
http://www.accura.com.hk/temp/P6200387-RT.jpg
The angle of view is further widened on both images.
As many of you know I prefer Olympus RAW converter but since E-P5 I found
the image edges are very chunky, looks over sharpened with USM at high
radius (say 1.5-2 pixels) even I set the sharpen to minimum. This forced me
to look for other RAW converters. widened
Further checking the images after this discovery, I believe Olympus has made
the following process to its image on both JPEG and its RAW engine:
- linear distortion correction
- chroma and fringe adjustment
- crop the image heavy
- Resize the image to fit the pixel size, in that case enlarge the image to
fit 4608x3456 on the E-P5
The last process creates a big issue on the natural look of the image, which
looks realy bad for pixel peeping. Now I understand why the images taken
with my OM Zuikos looked much better than the 4/3 native lenses as no
correction/cropping is done with the non native lenses.
Comparing the angle of view of my old 11-22 at 11mm and the 12-24 at 12mm, I
believe the 12mm is much narrower than quoted on a E-P5 with Olympus Viewer.
As you know even half a millimeter counted at wide angle, it is too bad to
see the result like that.
C.H.Ling
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