no distortion with Lumix 20mm f1.7 on E-P2

[Allan Ostling]

I was expecting to see distortion in the jpeg images I shot with the Lumix 20mm f1.7, mounted on my E-P2. But as you can see by the following, there is no distortion visible at all. We know the lens has sizable barrel distortion, so it's obvious that the distortion is being corrected by the Olympus software.

Is this something we can expect with every MFT lens, mounted on any MFT camera, something which is part of the Micro Four Thirds spec?

 

[Vivek]

Is this something we can expect with every MFT lens, mounted on any MFT camera, something which is part of the Micro Four Thirds spec?

Yes.

 

[Allan Ostling]

Yes.

Can you expand on this a bit? I'd like to know more about this part of the MFT specification which addresses this issue.

 

[Vivek]

Allan, Welcome to the forum!

The m4/3rds lenses have a lot more electronics in them than real glass. They are programmed to correct (digitally) for many aberrations. Geometric distortion corrections, chromatic aberration corrections, vignetting corrections etc. I suspect that even contrast is also tweaked (20/1.7).

What they can not do is to stop the a lens (20/1.7) from fluorescing in UV (does mess up metering when UV levels are high) or reduce the flare (20/1.7 again).

 

[Allan Ostling]

Allan, Welcome to the forum!

The m4/3rds lenses have a lot more electronics in them than real glass. They are programmed to correct (digitally) for many aberrations. Geometric distortion corrections, chromatic aberration corrections, vignetting corrections etc. I suspect that even contrast is also tweaked (20/1.7).

What they can not do is to stop the a lens (20/1.7) from fluorescing in UV (does mess up metering when UV levels are high) or reduce the flare (20/1.7 again).

Thanks Vivek. If you are from Maastricht I was very close when I spent 2 January 2010 in nearby Aachen. I intend to explore the Netherlands on my next trip overseas. My grandmother was born in Zwolle in 1883, and I want to see the house where she lived before emigrating to USA in 1910.

That the distortion is corrected in-camera is evident. I don't see any CA, but ascribed that to the fact that the 20mm f1.7 is well-corrected for this. So if CA is indeed corrected too, that is very encouraging.

 

[vincechu]

Hi guys, I thought that corrections are made only in Panasonic camera bodies?

Hope i'm wrong though as it would be good news for m4/3 as a whole system

 

[Allan Ostling]

Hi guys, I thought that corrections are made only in Panasonic camera bodies?

Me too. That's why I was so surprised to see the perfectly straight verticals at both sides of the image.

Here's another example, which should remove any doubts about there being no barrel distortion in the jpegs.

 

[Ario Arioldi]

Distortion correction is supported also in Olympus cameras.
Cheers,
Ario

 

[Allan Ostling]

Distortion correction is supported also in Olympus cameras.
Cheers,
Ario

Apparently this is true, but it is counter to what I had read before buying this combination. Can you supply some reference, which will verify that Olympus supports distortion correction of Panasonic lenses, and perhaps future MFT lenses made by other manufacturers?

 

[Abbazz]

Apparently this is true, but it is counter to what I had read before buying this combination. Can you supply some reference, which will verify that Olympus supports distortion correction of Panasonic lenses, and perhaps future MFT lenses made by other manufacturers?

Neither Olympus nor Panasonic communicate openly about software corrections applied by the camera firmware, but it is widely known that both the G1/GH1/GF1 and the E-P1/P-P2/E-PL1 apply in-camera distortion correction to the images. As for lateral chromatic aberration, it is only corrected by Panasonic Micro 4/3rds cameras.

Here's a couple of quotes from the Lumix 20mm review on DPReview:

Distortion is being corrected in software, with absolutely neutral results returned on both the G1 and E-P1.

When used on Panasonic bodies, lateral chromatic aberration is corrected in software and is effectively removed. However this isn't the case using the Olympus EP-1, and on this camera fringing is visible (although not hugely objectionable).

Cheers!

Abbazz

 

[trisberg]

Does this in-camera correction of CA apply to the RAW files as well as JPEGs?

It's my understanding that the barrel distortion correction isn't applied to RAW but it is handled in some RAW converters. Is it the same for CA correction. If so, does the camera body matter or are corrections applied simply based on what lens was used? Anyone know this?

-Thomas

 

[pellicle]

CA is stored as metadata in the raw files, so software which later renders it to something can apply that if it wishes.

this is done in camera on the micro4/3 cameras for lenses which the camera knows about.