Jupiter at different powers

[Marko of Oz (Mark)]

Captured on 3/9/09.
A fair example of how the image degrades at higher powers and poor seeing.

It's nice to get some image scale but not at the expense of quality.

image;
1) with 2x barlow(a cheap one) + filter wheel
2) with 2x barlow + 75mm extension + filter wheel
3) with 5x powermate + filter wheel

I think I need to invest in a TV 3x barlow for the 363 days of the year that the 5x is just too much.

cheers

Mark

[andrew2008]

Love the pics. Especially the first. Are these taken just on the gear in you sig?

[Quark (Trevor)]

Hi Mark,

Interesting comparison.

The greater the magnification you use the greater is any slight error in collimation and focus also magnified.

At very high magnification any air currents in your scope tube or in the boundary layer of air in contact with your primary mirror are also magnified.

To get good results with the powermate you are probably in the realm of Peltier cooling, at least the image scale for your scope with the powermate, still fits Jupiter on your chip.

I use a TV 3x Barlow with a 30mm extension which delivers 5.3x in my optical system.

Good Luck with it.
Regards
Trevor

[Marko of Oz (Mark)]

Originally Posted by andrew2008

Love the pics. Especially the first. Are these taken just on the gear in you sig?

In a word, yes.

[Paul Haese]

This is a perfect illustration of what hi resolution imaging is really all about. To get a really sharp image at high resolution not only does the seeing have to be good, but all the other factors must be honed.

I ensure that my mirror is at 0.3 at all times to prevent boundary layer issue. My collimation is kept at a premium, each night checking it rigorously to ensure that is has not slipped even just a bit. Interestingly the C14 holds collimation very well.

As for focus, I check it for each run. Subtle temperature variations change focus within minutes, sometimes even seconds.

Thanks for demonstrating what different scales require.