Mersing Sept 2012

[Gary]

Good stuff Kelvin! Thanks for sharing.

[cataclysm]

SO nice!
Quick question: The flare around the bright stars in the M45 shot seem to be asymmetrical. Is this because of the coma corrector, miscollimation or camera tilt, or is it a feature of this imaging setup? Just for learning

It's a bit of everything, lol..... but mainly due to secondary mirror offset relative to the main mirror, particularly obvious from bright point source like those bright stars.

[orly_andico]

Kelvin,

I got a quick question.

Do you guide in declination? is your declination biased a bit so that guiding is only required in one direction?

I'm having a heck of a time with declination guiding on my AP600 (there's a good deal of backlash and stiction - even though my PE is quite low).

I was looking at an AP900 QMD but nobody on ap-ug can tell me if it has better declination guiding characteristics than the 600, and Roland wasn't terribly helpful except to say the Mach1 has tighter tolerances than the 600.

Also does the Mach1 require a slight east bias on the RA as well? (the 900GTO does not, but it's just too much dollars for me)

[cataclysm]

Kelvin,

I got a quick question.

Do you guide in declination? is your declination biased a bit so that guiding is only required in one direction?

I'm having a heck of a time with declination guiding on my AP600 (there's a good deal of backlash and stiction - even though my PE is quite low).

I was looking at an AP900 QMD but nobody on ap-ug can tell me if it has better declination guiding characteristics than the 600, and Roland wasn't terribly helpful except to say the Mach1 has tighter tolerances than the 600.

Also does the Mach1 require a slight east bias on the RA as well? (the 900GTO does not, but it's just too much dollars for me)

Hi Orly, I guide on both axes, didn't intentionaly put any bias on any axes to aid guiding. I firmly beliefs that polar alignment should be as precise as possible, thus limiting the auto guider the need to constantly making corrections. In fact, I put in a great deal time on drift-alignment before the start of an imaging session just to make sure the polar alignment is precise enough. I can see that you have already pin point your dec axis problem, play and stiction, try to eliminate or at least reduce the mechanical issues first, guiding should improve once that is sorted. I used to have the same problem with my GM8, almost out of wits on how to solve the issue, till when I decided to strip and thoroughly clean both axes and upgrade to more precise worms. It now works like a charm.

[orly_andico]

hi Kelvin,

Yup I have cleaned the DEC axis (never had any problems in RA). Can't fully get rid of the stiction though.

Are you using PHD for guiding? or something else? some of the other software have settings for taking up backlash when reversing direction. Actually my aftermarket GoTo controller also can do this, but I can't figure out the settings.

[KKK26]

As usual..great images

[shirox]

ok this is not from mersing but rather its from Punggai last year.
Trying out come processing techniques from Kelvin and playing with it.
Does brings out fine inner details of the nebula.
the dark side!!!!

[wucheeyiun]

Nice layering nebula detail of m42...very 3 dimensional...

[KKK26]

Nice Bro. So next trip, I won't disturb Remus & Kelvin, I will disturb you for AP

[shirox]

haha booking open for next year! haha