Video Camera

[euphony]

Oh, and i'm not using a light pollution filter with it.

I have a skywatcher light pollution filter that I bought ages ago. Having used it visually I see absolutely no difference from using it and not using it in all honesty. I'm not in a massively light polluted area (hence my surprise at the terrible video images!).

I think i trialled it a while back with the mintron, but once again I saw absolutely no difference.

[DoctorD]

Hi Chris

The distance from the reducer to the sensor is what affects the actual reduction achieved - the greater the distance the greater the reduction however there will be a limit to how much can be achieved.

It sounds like you have the reducer in the right place - I'm not sure that it will fit directly onto the camera (different thread). If you put the LP filter between the nose piece and the reducer you should get slightly greater reduction.

There will always be some noise with a CCD that is not cooled.

All the best

Paul

[euphony]

Thanks Paul

[euphony]

With all that in mind, I have purchased an extension tube as a temporary measure to see if that makes any difference.

Bernard now seems to think that could be the problem, as I need to cram all the available light into a much smaller area so increasing it's intensity by the inverse square, which should make a huge difference. Ultimately I need to get the f3.3 for the best performance.

So the next step is to save for the f3.3 focal reducer and buy it without the wife finding out

(no, seriously! )

[euphony]

A very quick experiment with the extension tube before the clouds rolled in seemed to show promise. The sky wasn't dark yet, so i couldn't make a final judgement on the overall noise, but the field of view was much much wider and I'm pretty sure there was more detail showing despite the slightly lightish sky. Had to stop after 10 minutes though! Boooo to the UK weather, the next week looks rubbish too!

[DoctorD]

Hi Chris

Hope you get a clear night soon. Glad that the extension tube seems to make a difference. If you are seeing a significant increase in FoV then I would expect TW noise to come down.

Clear skies

Paul

[alan potts]

Paul,

Forgive me for asking a stupid question but these filters you use, they are only because of the street lamps? I don't have a light for about 100 yards and it is as old as me, all my light comes from the house and I own the switches. Apart from the mountain of snow we have had falling for 2 days it's ideal for a astrosite. I get a little sky glow from the town which is 4 miles away to the east but if you saw it here I am sure you would love it.

Merry Christmas,

Alan.

[DoctorD]

Hi Alan

It's more to reduce the skyglow and the IR rather than direct light.

HTH

Paul