Canon, Olympus and Panasonic Lens Tests on the Panasonic GH-1

Written by Gary on September 22nd, 2009

A few posts ago, I discussed results of my simplistic lens tests (photographing a lens resolution chart at variable distances according to effective lens focal length to keep chart size almost constant with careful live view magnified manual focus on tripod with self-timer).

I have now placed double-sized crops (ie. cropped the centre of the images and uploaded using PS to double the size of the image which equates to viewing these images at “200x” in PS and then compressed them to 29% jpeg compression) of these images on my website here so that you can get a better idea.

Most people do not like looking at photos of lens resolution charts, so if you fall into this category, then don’t look, just check out the photos I take with the lenses here instead.

The main conclusions of the tests were posted in these blogs:

In the previous post of the EF 85mm lens in action, Jeff commented on the purple fringing and whether it is sensor blooming rather than chromatic aberration given the absence of green fringing as well.

From the lens tests, the new ED glass lenses such as Canon L lenses and Olympus ZD 50-200mm lens had minimal if any purple fringing even wide open.

In comparison, older legacy lenses (even the EF 85mm f/1.8) with no ED glass showed much purple fringing but no green fringing wide open which tended to improve substantially as one stopped down.

Thus I suspect it is not sensor blooming per se that causes this but perhaps an interaction between the sensor microlenses and chromatic aberration or perhaps lack of telecentricity of the lenses which tends to be worse wide open.

I have older lens tests using the same technique here (but chart magnifications may not be identical to that above so may not be directly comparable):