Artifacts in barlows - what should I do?

[Kirkus (Kirk)]

I'm having a problem that I'm sure others have seen, and I'm just at a loss about what to do. I have artifacts of some sort on my cheap 2x barlow and my Meade 3x TeleExtender. When using either of them to shoot video of a planet, the planet's image takes up a lot of space and I can't get images without these artifacts ruining the shot. I'm sure they aren't dust, but rather something in the glass... I think.

Attachment 1 is of the 3x Meade
Attachment 2 is of the 2x barlow

Any suggestions?

[iceman (Mike)]

Are you sure it's not dust on the webcam chip?

Have you tried cleaning the optical surfaces on your barlow or the CCD?

[Kirkus (Kirk)]

I'm not completely sure that it's not dust on the chip. I've assumed that it wasn't because the patterns are different depending on which barlow I have the camera attached to. I've cleaned both barlows but have only "blown out" the ccd chip. I've not actually "cleaned" it by touching it with anything.

[Kirkus (Kirk)]

Oh my goodness. The problem isn't with either of the barlows. While running video with the camera attached to each barlow, if I rotate the barlows, the marks don't rotate. Which leaves the ccd chip as the culprit. Thanks, Mike, for getting my head thinking in that direction.

[iceman (Mike)]

No worries Kirk - that's what I was going to suggest. The dust does look the same in each of the images above, and rotating the camera (or the barlow) would prove the culprit.

Use a q-tip dipped in distalled water and gently wipe across the chip.

[Kirkus (Kirk)]

Originally Posted by iceman

No worries Kirk - that's what I was going to suggest. The dust does look the same in each of the images above, and rotating the camera (or the barlow) would prove the culprit.

Use a q-tip dipped in distalled water and gently wipe across the chip.

Holy cow. It's a thing of beauty now. Thank you so much!

I've fought for over a year trying to place the image in a "sweet spot" that didn't have any thing on it. I don't know why I struggle with this stuff before asking for help here.

[Kirkus (Kirk)]

Despite the lousy seeing conditions, I set up tonight and shot some video of Jupiter. Nothing worth even processing, but it was fun to move the image around on the chip anywhere I wanted it!

Thanks again, Mike.

[iceman (Mike)]

Great to hear, Kirk

I've had dust motes from time to time as well, as know how annoying it is when it's right in the middle of the field

[scopemankit (Chris)]

Apply flat fields to your image, that should eliminate the problem.

[iceman (Mike)]

Originally Posted by scopemankit

Apply flat fields to your image, that should eliminate the problem.

Not (easy) for planetary imaging.