LPF Reflection help please

[Earl]

Here is a with and without image and as you can see removing the LPF removes the reflection, any ideas how i can solve this?

Could the reflection be due to the LPF been before the flattener in the light path?

Im usign a 2 inch Astronomik CLS filter on the end of a skywatcher flattener

[Star Gazer]

Rotate or mirror in Photoshop or similar shop get you sorted

[Earl]

it could be my imagination but do i see a reflection in the one without the LPF filter also?

[Star Gazer]

Hi Earl_UK,

In your first post you said you thought there was reflection of the image after using the filter. In your subsequent post you're saying you no longer see it - I'm confused

May be you're thinking that the filter is 'erecting' the image. If you are, then this would not be right as the filter would have to work like a lens, by refracting light. An LP filter does not refract light, it merely filters out light of a certain wave length.

Looking at the two images you posted I thought the one might be rotated 180^ but its not so easy to tell just by casual inspection. May be after fitting the filter you mounted the camera the other way up?

[Psychobilly]

I would say the slightly offset "halo" is in both... but much easier to see in the filtered image...

Peter...

[Earl]

The offset Halo is very obvious in the image with the Filter in (orientation is not an issue i just couldn't be bothered to rotate the jpg.)

I might be imagining it, but it could actually still be there with the LPF removed.

However there is a Halo just above the center on the image without the LPF, which makes me think that I still have a reflection going on somewhere.

[Psychobilly]

That one looks more like a dust bunny to me Earl... the Reflection is very faint but looks the same as the one in the filtered image...

Peter...

[Earl]

That one looks more like a dust bunny to me Earl... the Reflection is very faint but looks the same as the one in the filtered image...

Peter...

Im not so sure on the dust bunny as it does not show in the filtered image, however it is possible that it is and the dust bunny was introduced when the filter was removed.

[Earl]

I have decided to get my Filter wheel up and running and see if the LPF much closer to the CCD solves the issue.