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These are often confused with emission points, which CAN be bad.
A bright spot is a bit different however. Here is the technical definition-
Bright Spots-
These can be defects in the image area produced by the NVG. This condition is caused by a flaw in the film on the microchannel plate. A bright spot is a small, non-uniform, bright area that may flicker or appear constant. Bright spots usually go away when the light is blocked out and are cosmetic blemishes that are signal induced.
I underlined the important part- these are considered cosmetic blemishes.
"But they are never listed on tube data sheets"
Yes. Only black spots .003 or larger are usually shown on the spot spec chart on data sheets. However there are a lot of various cosmetic issues with a tube that are NOT shown on the tube data sheet including bright spots, small areas that are slightly off color, even small lines, etc.
Small lines are the biggest PITA in my opinion because you think at first it is debris in field. So you clean the unit several times only to find no it's just a little line in the tube itself.
What is a bright spot? Easy way to think about it is that it's just a spot that is white instead of black. Good news is they are usually very small- pepper speck size.
They can be found in ALL grades and types of tubes.
I'll post a pic next time we see one that would make a good example.
A bright spot is a bit different however. Here is the technical definition-
Bright Spots-
These can be defects in the image area produced by the NVG. This condition is caused by a flaw in the film on the microchannel plate. A bright spot is a small, non-uniform, bright area that may flicker or appear constant. Bright spots usually go away when the light is blocked out and are cosmetic blemishes that are signal induced.
I underlined the important part- these are considered cosmetic blemishes.
"But they are never listed on tube data sheets"
Yes. Only black spots .003 or larger are usually shown on the spot spec chart on data sheets. However there are a lot of various cosmetic issues with a tube that are NOT shown on the tube data sheet including bright spots, small areas that are slightly off color, even small lines, etc.
Small lines are the biggest PITA in my opinion because you think at first it is debris in field. So you clean the unit several times only to find no it's just a little line in the tube itself.
What is a bright spot? Easy way to think about it is that it's just a spot that is white instead of black. Good news is they are usually very small- pepper speck size.
They can be found in ALL grades and types of tubes.
I'll post a pic next time we see one that would make a good example.