# E-M5 flare problems with Pany 7-14mm

Started Sep 2, 2012 | Discussions thread
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 Re: E-M5 flare problems with Pany 7-14mm In reply to noirdesir, Nov 26, 2012

noirdesir wrote:

Anders W wrote:

Michael J Davis wrote:

I'm just getting round to testing a few theories (I saw your posts in the other thread), and am wondering how microlenses might affect the flare.

However, When I looked at the original image I posted at the top of this thread and other similar images, I found that the flare lies always along (halfway, I think) a line jointing the optical centre (i.e. middle of frame) to the light source.

Now, the arrangement of microlenses (I know nothing about these) is presumably rectilinear, so I'd expect a difference between the type of flare on a diagonal compared with vertical or horizonal line. I'm trying to set up a simple set of tests.

However, I don't know what you mean when you say they are arranged rectilinearly (rectilinear is the ordinary kind of lens projection, making sure all lines that are straight in reality remain straight in the image at the expense of some other problems like perspective distortion). They are arranged in rows and columns, just like the pixels. There's one microlens on top of each pixel.

The microlenses are not circular, they are square. While the only optically active part might the center part roughly covering the area of an inscribed circle into the square and this center part is thus circular, the distance between each center of the each microlens is larger when going over a sensor diagonally is larger then when going over it parallel the edges of the sensor.

I don't think the active (light-sensing) part of each pixel is circular thus somewhere from the top of the microlens to the active part, the shape changes from circular to square (or square-ish), thus the response to light of the whole assembly should slightly differ depending the direction of the light (diagonally or parallel to sensor edge) as the whole assembly does not have circular symmetry and does should react differently depending on the direction of the light hitting it. Even if all optically relevant parts were circular, one would still have a different 'pixel pitch' depending on the direction of the light (diagonally or parallel to sensor edge).

That is what I think Mike meant, whether that has any influence on the phenomena of magenta ghosting depends on what exactly your theory is based on.

Sorry, been afk for a few days...

... yes that's a pretty good summary of what I was trying to express. Thanks

Mike

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Mike Davis
Photographing the public for over 50 years
www.flickr.com/photos/watchman

Michael J Davis's gear list:Michael J Davis's gear list
Panasonic Lumix DMC-G1 Olympus OM-D E-M5 Panasonic Lumix G Vario 14-45mm F3.5-5.6 ASPH OIS Panasonic Lumix G Vario 7-14mm F4 ASPH Panasonic Lumix G 20mm F1.7 ASPH +2 more
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