Decent image scale on planets, how?

[Ant]

Well, removing the IR pass filter had made a massive difference!

I imaged Saturn last night and found that 1/275sec with gain at around 3/4 gave a nice brightish disc.

I threw in the Barlow which droped the exposue to about 1/80 (from memory), but that still meant that I could image at 60fps - which with planets is half the battle.

I'll post the images tonight.

Think I need to work on focusing and buy a decent barlow.

Ant

[dark knight]

look forward to seeing the images Ant.

[Darth Takahashi]

Let me know how this experiment goes on? I'm also in the same position. So far I have only been able to push my M250 to 1.5x F11 and that was a struggle even with an IR pass filter and a Philips SPC900 webcam...

Definitely really interested in your results.

Neil.

[omneferuss]

Hi, I'm curious as to why you'd use an IR-pass filter? If for severe light-pollution, is this for economy vs a LPS filter ? ...and doesn't higher f-ratio itself alleviate much of the effects of light-pollution anyway ?

In fact, I've been led to believe that it's best to use an IR(&UV)-cut filter for planets ( for one-shot colour, anyway).

[beamish]

My understanding is that the benefit of using an IR Pass filter is, that on bright objects like the Moon, it blocks almost all of the visible light, thus resulting in "improved seeing" in that some of the atmospheric turbulence in taken out that would otherwise cause a poor image. But this is at the expense of frame rate, requiring more gain and then noise. This applies to ccd's without an inbuilt IR filter obviously.

I prefer the no.25 red filter to do an almost similar job-Both improve contrast too IMO.

I hope that makes sense.

[omneferuss]

Ahhh, thanks beamish. I see, it's the "seeing" it's about and it limits the imaging to monochrome then.. or 'luminence' channel to go with other RGB capture ? (giving better detail in final image ) ?