Is there an easy way to stop this light scatter ghosting in all my photos & videos of engine valves?

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.

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/sho....php?t=1181089

And he
http://www.bimmerfest.com/forums/sho....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.

On Fri, 15 Dec 2017 06:23:18 -0000 (UTC), 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.

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/sho....php?t=1181089

And he
http://www.bimmerfest.com/forums/sho....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.

OK. That's one possibility eliminated.
--

Regards,

Eric Stevens

Eric Stevens wrote:

OK. That's one possibility eliminated.

It's not the camera or the lens other than it's a "property" of them under
those lighting conditions.

The weird thing was the streaks of light are huge. They're not just
reflections. And they are at the same angle for /all/ objects, and they're
long. They go halfway through the photo.

It's like it was sleeting at the time and the light reflected off the
sleet.

I knew a point source of light was a bad idea (actually my shop lights are
pretty good in that they're a classic photography aluminum cone with clamps
on one end and the opening is huge - about 8 or 9 inches - which are actual
photography lights I bought at a garage sale decades ago.

The weird thing was the sleet across the entire photo which couldn't have
been a reflection because they were all at the same angle. There's
something in the physics involved of the way cameras work that caused those
huge streaks of sleet.

PS: To be called a troll for asking this question is kind of ridiculous.

In article , Arthur Wood
wrote:


PS: To be called a troll for asking this question is kind of ridiculous.

you're called a troll because of your extensive history being one.

Arthur Wood wrote in
news
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.

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/sho....php?t=1181089

And he
http://www.bimmerfest.com/forums/sho....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.

The "physics" are because the smudge on the lens is at a 45 degree angle.

Jeff wrote:

The "physics" are because the smudge on the lens is at a 45 degree angle.

It's not a smudge. I don't know what it is, but it's not a smudge.
I wiped the lens because that's the first thing I had thought also.

Anyways, it doesn't happen on pictures that don't have that lighting
situation, even at the same time.

There's something about the lighting combined with the way cameras work.

This is the light fixture that I use as my mobile shop light.
https://www.turboimagehost.com/p/368...ight1.jpg.html

I bought it at a yard sale where it was claimed to be a photography light.
Is that a typical photography light?

Currently it has a curly bulb inside a floodlight fixture (PR-something).
What bulb do you normally put in those photography lights?

nospam wrote:

you're called a troll because of your extensive history being one.

It's a legitimate question.
Yours are all trolls.

plonk

On 2017-12-15 19:32, Arthur Wood wrote:
Jeff wrote:

The "physics" are because the smudge on the lens is at a 45 degree angle.

It's not a smudge. I don't know what it is, but it's not a smudge.
I wiped the lens because that's the first thing I had thought also.

Anyways, it doesn't happen on pictures that don't have that lighting
situation, even at the same time.

There's something about the lighting combined with the way cameras work.

Try another camera.

--
Cheers, Carlos.

On 12/15/2017 01:18 AM, Arthur Wood wrote:
PeterN wrote:

I think that your answer is a good response to a real problem.
Some here may have encountered it and you provided an answer that would
help them.

I see the solution is a "diffuser" but what's the "problem".
What I mean by that is why does the light look like it's raining?

For whatever reason, it's like "sleet" at a 45 degree angle.
Where is all that "sleet" of light coming from?

And why always a 45-degree angle?
I assumed that some "physics" principle is being invoked.

No matter how I held the camera, I still got a 45-degree "sleet" of light.

Take this one example from far away:
https://www.turboimagehost.com/p/368..._bay4.jpg.html

Compared with this at 90 degrees:
https://www.turboimagehost.com/p/368..._bay6.jpg.html

Compared with this at a closeup:
https://www.turboimagehost.com/p/368...bay10.jpg.html

All have this "sleet" of light at the same angle.

Why the 45-degree "sleet" angle in /all/ the photos?

I realize the /solution/ is a diffuser but what's the physics problem?
Is there a physics principle that causes the always 45 degree sleet?


Is it possible that your lens is dirty, possibly with some sort of oil-
skin or otherwise?

--
Ken Hart

On 12/15/2017 1:18 AM, Arthur Wood wrote:
PeterN wrote:

I think that your answer is a good response to a real problem.
Some here may have encountered it and you provided an answer that would
help them.

I see the solution is a "diffuser" but what's the "problem".
What I mean by that is why does the light look like it's raining?

For whatever reason, it's like "sleet" at a 45 degree angle.
Where is all that "sleet" of light coming from?

And why always a 45-degree angle?
I assumed that some "physics" principle is being invoked.

No matter how I held the camera, I still got a 45-degree "sleet" of light.

Take this one example from far away:
https://www.turboimagehost.com/p/368..._bay4.jpg.html

Compared with this at 90 degrees:
https://www.turboimagehost.com/p/368..._bay6.jpg.html

Compared with this at a closeup:
https://www.turboimagehost.com/p/368...bay10.jpg.html

All have this "sleet" of light at the same angle.

Why the 45-degree "sleet" angle in /all/ the photos?

I realize the /solution/ is a diffuser but what's the physics problem?
Is there a physics principle that causes the always 45 degree sleet?


The Duck gave you a pretty good practical resolution. To e e it looks
like a point source lighting problem. u.e. your lens resolving power is
insufficient. Diffusion breaks up the point source lightning,

IOW Mathematically an object may be considered a point source if its
angular size, is much smaller than the resolving power of the lens:
Ether diffusion, or a lens with higher resolving power should solve
your problem






--
PeterN