lens distortion - help please!

[Mike Dominic]

Does anyone know what is causing the weird distortion in the foreground of this photo? It looks like water/stained glass. I would like to figure it out so I can prevent it in the future if possible. This was a 50mm still lens at about 5.6 or 8. It seems to only happen when something very bright (like the grass) is behind a blurred foreground object. Thanks for your help!

 

[Phil Holland]

This is an optical phenomenon that occurs under certain conditions when you have a busy shape essentially making a "false iris" like the foreground tree in the example you posted.

Often it reveals itself near the edges of the out of focus object closer to the lens itself.

While undesirable at times you can use this effect for some creative shots if observed and executed carefully.

In this particular case a longer lens and more distance might have helped eliminate the effect. Potentially shooting at a wider aperture would change the way it renders and might solve it's "busy look" too.

Reading up on how Circles of Confusion (aptly named) work actually describes this phenomenon outside of the lens.

I have noticed on certain lens designs that exhibit more of a cone of distortion to the out of focus image that this effect can be exaggerated at times. You'll also see highlight edges of out of focus images sometimes "grab" onto a darker background color and suck it into it's own distortion and vice versa. This is actually fun to play with at different focal lengths, magnifications, and wider apertures.

 

[Mike Dominic]

thanks phil! at least i know now to be more aware of it.

 

[Glen Powell]

I think I'd be more worried about the giant grey block in the top left hand corner - I think it might be a sensor issue... It would be great if someone from RED would chime in and resolve this issue before the inter webs light up and get out of control.














/*Sarcasm

 

[Josef Gatti]

Haha Glen, I was working up a similar joke but could not have executed that any better. Back on topic, I have never encountered this either. Does anyone have any ideas on what items could be used to try and recreate this at home? Seems like it could be used for some fun, I want to get to know it

I think I'd be more worried about the giant grey block in the top left hand corner - I think it might be a sensor issue... It would be great if someone from RED would chime in and resolve this issue before the inter webs light up and get out of control.

/*Sarcasm

 

[paul schefz]

in 30+ years of taking pictures i have never seen this happen with a lens/sensor/film...to me it looks like some weird compression or maybe stabilization thing?
if it is a optical flaw of sorts, it should be pretty easy to replicate...