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View Full Version : Non-parallel lines in picture...Lens fault or user fault?



kazaan
02-25-2005, 07:27 PM
Hi,

I got Sony P200 just 2 days back..
still experimenting with it...

i took a pic in front of a mirror....as u can see the two edges of mirror are not parallel...
is it my fault or is it LENS or is it the way its supposed to be?


thanks
kaz.

Norm in Fujino
02-25-2005, 07:46 PM
best bet is that you're tilting your camera slightly so that it's not perfectly perpendicular with the plane of the lines.

kgosden
02-25-2005, 09:24 PM
The non-parallel, but still straight lines definitely indicate that the sensor plane and that of the mirror are not parallel (in other words, the camera is slightly titled), If the lines were not straight, rather bowed in or out, then you would be seeing an effect caused by the lens itself.

kazaan
02-25-2005, 11:36 PM
The non-parallel, but still straight lines definitely indicate that the sensor plane and that of the mirror are not parallel (in other words, the camera is slightly titled), If the lines were not straight, rather bowed in or out, then you would be seeing an effect caused by the lens itself.

Thanks....
i will try to shoot that again and hopefully i can keep it perpedicular now..

dwig
02-26-2005, 05:01 AM
Actually, in the sample picture the lines are both bent (bowed out) and non-parallel.

The bowing is a common optical fault; it is a rectilinear distortion commonly refered to as "barrel distortion" when they bow out, as in this picture, or "pin-cushion distortion" when they bow inward. No lens is perfect, but today's compact zoom lenses with exceptionally wide zoom ranges usually exhibit significant distortion.

The lack of being parallel is the result of the film/sensor not being exactly parallel with the mirror. Where this is a "fault" or not is more of an artistic opinion than a technical fact. It is, though, not the fault of the camera. This problem is why the view cameras traditionally used by architectural photoraphers commonly have levels attached.

John_Reed
02-26-2005, 08:39 AM
Hi,

I got Sony P200 just 2 days back..
still experimenting with it...

i took a pic in front of a mirror....as u can see the two edges of mirror are not parallel...
is it my fault or is it LENS or is it the way its supposed to be?


thanks
kaz.I made the lines more vertical (Photoshop de-skewing), but couldn't totally eliminate the barrel distortion.

Samuel Lo
02-27-2005, 08:39 PM
I made the lines more vertical (Photoshop de-skewing), but couldn't totally eliminate the barrel distortion.


I think you'd better to re-take the picture, not just edit it.