Olympus-OM
[Top] [All Lists]

[OM] Olympus 12mm is not 12mm?

Subject: [OM] Olympus 12mm is not 12mm?
From: "C.H.Ling" <ch_photo@xxxxxxxxxxxxx>
Date: Sat, 20 Jun 2015 14:44:57 +0800
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
















--
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/

<Prev in Thread] Current Thread [Next in Thread>
Sponsored by Tako
Impressum | Datenschutz