"Moustache" distortion in the 12~40/2.8 PRO Zoom: (Tested on the E-M1 with firmware v 1.1.)
Don't misunderstand me. I own and love the 12~40/2.8 PRO Zoom. But there are problems with it and it seems that
most reviewers are not willing to mention them; for fear that they will be cut off future test units. This is an unfortunate reality for most reviewers.. Fortuantely, for me, I have no connection to Olympus, other than as a satisfied user of many years standing. Thus, I have no such worries! They don't send me loaners for review, anyway!
There has been a trend, in recent years, particularly with micro-FourThirds lenses, to build the lenses leaving a lot of the distortions uncorrected. Panasonic started this and Olympus has picked it up. Personally, I think it's a bad habit. It does, however, allow their designers to build smaller, lighter lenses with otherwise excellent performance, at a more reasonable cost.
The argument goes that if you're shooting jpegs, the camera will correct the distortion during conversion, and you'll never
see it. And if the picture is perfect when it comes out of the camera, what more can you want?
Correspondingly, if you shoot raw and develop your images using Olympus Viewer 3, or one of the commercial packages
which have the distortion profiles built-in (and which will automatically correct it during developement) then you'll still
never see it. So far,so good.
But, what if - like me - you are addicted to one of the more obscure, but very effective, commercial raw developers - such
as Silkypix - or one of the open-source ones - like RawTherapee? Neither of which offer automatic distortion correction. Now, you have a problem!
For the Olymlpus 12~40/2.8 PRO Zoom suffers from some rather serious, "moustache" distortion!
Now, I've been shooting since the mid-1960's, and I'd never heard of this form of distortion, until recently! So, if you
haven't either, don't feel bad. But it is real and it does exist in the 12~40/2.8 PRO Zoom.
Over the years, PTLens has developed into an excellent, low cost, very fast and easy-to-use program to correct
distortion in all manner of lenses. The lens database includes some 2400 separate calibrations — far more than any
other application of it's type. (BTW: the $25 license fee is good for as many computers as you own and is a one time fee, covering ALL future updates & versions. Very fair!)
Better yet, PTLens is a simple batch processor. It reads the exif data of each image, disovers the lens & focal length, and then does the correction in fractions of a second. So, you can go through 40 or more images, in mere seconds.
So, now my workflow is as follows:
1) develop with RawTherapee or Silkypix.
2) Run developed jpegs through PTLens, correcting distortion. (Very Fast!)
3) Resize & use.
In this way, I can process 500 to 600 images, for a client, as fast as I can crop & develop them!
Clicking on either of the above images, will give you a web page, with bigger versions of these two images - making
it much easier to see the differences.
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