10" f6 for planetary?

Hello all,

I was wondering if Discovery's 10" f6 would be any good for planetary and lunar observing? I have read that lower f-ratios are only good for deep sky but f6 seems good for a 10", which are normall f5 and lower. What about the possibility of a partial aperture mask? Any and all tips and advice would be appreciated - I may finally get that first "real scope" in the next 6 months... I want good aperture for nebulae, galaxies and clusters... but I sure do looooove our corner of the universe as well.

Ken

Should be very good. Lower focal ratios can be very good too. A well figured mirror is a well figured mirror
Aperture masks can make moment to moment views steadier in bad seeing conditions, but are put aside when seeing is good. More aperture means better resolution potential as you know.

Clean seeing!
John W.

The main element in good planetary views is the overall optical quality of the instrument. The main differences between say an f/4.7 and an f/6 is that it's generally easier to get a "good" figure in the f/6. The other feature that makes a longer f ratio scope good for planets is they generally have a smaller secondary. This issue becomes insignificant when compared to the impact of the overall optical quality of the mirrors.

A longer focal ration reflector will do just fine on DSOs, it's only limit is true field of view for the given aperture.

My limited experience with premium Discovery mirrors are that they are highly underrated and they produce excellent images when well collimated and thermally stable. I think if you can handle the size, their 10" f/6 would make a superb overall telescope.

Do some home upgrades like flocking the tube and installing a cooling fan or two and you will have a very fine telescope that will knock your socks off for a 10" scope.

Gary Weber