Mystery Marks

[Mamsoth]

Hi guys, I have noticed some quite conspicuous scuff marks on screen when using my TV x5 barlow in conjunction with my fusion webcam. Thinking it was the barlow I used some other cameras and noticed that the scuffs had gone but each camera showed a different configuration of black blobs . So I was able to rule the barlow out, it must just be dirty/scuffed ccds that are the problem.

The thing is, the marks are only visible when using the TV x5 barlow, when I use the 2.5x revelation, the marks just aren't there! Why???

Would really appreciate any help

Cheers

Matt

[Merlin66]

Can you image the marks?

Could be dust on the optics?

[Mamsoth]

Hi Merlin, it turns out it is a dusty sensor which is to blame on the atik (on the fusion it s a scuffed infra red filter that is causing the strange marks). Seeing the scuffs for the first time coincided with my first cleaning of the Televue, I was convinced that I'd scratched the lenses and was panicking a bit.

Do different barlows make ccd dust come to focus while others don't? When using the 2.5x revelation there are no blemishes or marks visible at all!

***First pic is the atik, the second is the fusion***