Subject: Re: Is there an easy way to stop this light scatter ghosting in allmy photos & videos of engine valves?
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From: PeterN <"peter,newdelete"@deleteverizon.net>
Newsgroups: rec.photo.digital,rec.video.desktop
Subject: Re: Is there an easy way to stop this light scatter ghosting in all
my photos & videos of engine valves?
Date: Fri, 15 Dec 2017 23:20:32 -0500
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On 12/15/2017 1:23 AM, Arthur Wood wrote:
> Eric Stevens wrote:
> 
>> I think you mean cams rather than valves.
>>
>> It looks to me as though the highlighted parts give rise to a strak of
>> light at an angle to the frame of the image. In some of the shots
>> (e.g. bay 10) streaks can be seen emenating from highlights other than
>> the cams. I suspect the problem may be due to a smear on the camera
>> lens. I suggest you try it with another camera.
> 
> You are correct in noticing that all the streaks of light are at the same
> 45 degree angle no matter how the camera is held.
> 
> That's why I think it may be some "physics" principle involved.
> 


Yep. See my answer above, and the formula at
<https://en.wikipedia.org/wiki/Point_source>.






> There are many other photos taken with the same camera but under daylight
> lighting where these streaks do not happen so it's not the camera.
> 
> Some of those photos are here.
> http://www.bimmerfest.com/forums/showthread.php?t=1181089
> 
> And here:
> http://www.bimmerfest.com/forums/showthread.php?t=1181289
> 
> So it's not the camera or the lens except under those lighting conditions.
> 
> I was assuming there is something weird in the physics of the lighting that
> causes those sleet like streaks always at 45 degree angles and far from
> being a mere reflection.
> 


-- 
PeterN