Re: Fiberscope Bending Damage Image

> Hi, What is the appearance in the image of a fiberscope,

> > borescope or endoscope if there is a bending damage > > where the cable is bend tighter than the allowered bending > > radius. What are you supposed to see in the image? > > Has anyone looked thru one? Thanks. > > > Mu > > I've looked though fiber borescopes though not one which has been > bent beyond it's minimum radius. I can think of two possible failure > modes. > > One would be that some of the fibers got broken. I'd expect that to > show up as dark "pixels" which don't pass light as well as unbroken > fibers, if at all. That would appear as semi random dark spots in the > image. The fibers in a borescope bundle don't have to be aligned except > at the ends, but there's no reason to expect they're completely random > either. > > The other failure mode is if some of the fibers weren't broken, but were > pulled away from the image plane at the eyepiece or objective end. In > that case I'd expect to see some areas out of focus relative to other > areas of the image. I'd expect out of focus fibers to be in bunches with > irregular edges. > > If the bundle was bent tightly but not broken or pulled away from the > image planes one might see the light from fibers which were most > tightly bent dimmed somewhat because of the loss of total internal > reflection, but I'd expect them to recover when the bundle was straightened. > > I'm assuming you're talking about a fiber bundle borescope, not a > cc/video_over_fiber/led borescope. > > What are you seeing in your borescope? If the above doesn't explain it > link a photo perhaps?

I don't experience pixel lost or out of focus image. Instead. I can see some lines at the periphery, about 5 lines getting smaller in length starting from the edge, the lines are not dark and one can still see the image in the fiberscope (or borescope) and not notice it.

Mu

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Mu
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btw.. the lines are only on one side of the image near the edge of the lens

Mu

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Mu

The following image is what it looks like.

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I took the picture in wikipedia, I drew the 4 white long oval lines near the edge. In my fiberscope, there is a very *slight* darkening in the 4 oval shapes but the pixels are not dead because one can still look at the image, it's like transparent. It seems there are more lines near the center and to other side but it's so very faded that one can't notice it. The fiberscope is a $250 borescope with rigid nylon covering, it has reportedly 7200 fiber bundles. Any idea what's causing it?? Hope someone who has actually looked thru a bent damage fiberscope can share what he saw...

Tnx.

Mu

Reply to
Mu

Hi guys,

After looking at the image a long time, it looks like the alternating black and white lines getting smaller is like looking inside a tube.. that is.. the lines seems to be superimposing on the image.. meaning they are not dead pixels. If the fibers are merely bent... i assume they won't cause alternating lines isn't it. So what internet tube is the fiberoptic seeing that is superimposing on the image?

Mu

Reply to
Mu

"i assume they won't cause alternating lines isn't it. So what internet tube is the fiberoptic seeing"

The results of looking at the image for much too long?

Reply to
Louis Boyd

I mean internal tube. The fiberoptic seems to be imaging the inside of some kind of internal tube within the nylon cord. I'm still analyzing what it could be. As the experts here pointed out, broken bundle would produce black pixels. But I wonder if the bundles can just have bend damage without totally destroying the bundles, it's like copper tube being halfly torn but still intact.. could this happen to fiber bundle too?

Also, fiber bundle is made of glass. How can glass bend in the first place?

Mu

Reply to
Mu

Ok. here are the actual images of the lines in the fiberscope image I took up with a camera. I merely added the white arrow to point to the alternating lines which appear in all images. In the picture, it is sky above the city.

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So how do you think the lines were caused by? bent, broken fiber bundles or tube inside the lens? Any ideas or theories? Thanks.

Mu

Reply to
Mu

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