M13 - 22 May 2011 00:00 to 02:30 BST

[The Thing]

Hi Robert,

Tuesday night had very little air movement, I double checked everything was balanced and well done up and that the cables were free and wouldn't catch anything.

I wish I had logged the guiding numbers or print screened the graph, someone might have been able to say - 'Oh yes that's the xyz being unflanged by the doodab' or something. I love these little mysteries, it would be boring if it all just worked perfectly!

[mickw]

Duncan, there is a setting you can/should change in EQMOD that stops weirdfulness happening with guiding

Change the default figure in Ascom Pulse Guide Settings to .5 or 5 (can't remember which) Chris told me so he'll know the correct value

Here's the menu screen - see top right
http://eq-mod.sourceforge.net/eqaindex.html

I

[The Thing]

HI Mick,

I tried upping the setting from the minimum (as it installs) 0.2 to 0.3 and it made things worse! Maybe I wasn't brave enough.

[mickw]

Must have been .5 then.
Definitely improved the wayward guiding issues - IRC the pulse guide setting slows the mount down enough so it receives the command from the guider before moving

[Rocket Pooch]

Hi,

The reason for upping it is to do with calibration and guide pulses, if you galibrate with a higher number in EQMOD the stars move further and the accurate angle and rate of movement can be recorded.  Thats all.

I guess you could fiddle with PHD calibration timings?

Chris

[The Thing]

Hi Chris,

I had already set the PHD callibration timings to 2500ms to compensate for the short focal length (190mm) finder guider scope to get the full 25+ pixel movement required in around 12 steps. Of course that doesn't affect the actual guiding. I will try increasing the EQASCOM setting and see what happens.

[The Thing]

Yet another M13! The setup is the same with 34 of 38 subs stacked, 6x300s + 32 x 120s (EQMOD crashed doing the 300s subs).
The major difference is a 5mm T spacer between the Baader SCT to T mount unit and the Canon adaptor. And lo, there were round stars! (maybe no quite round enough for you perfecionists!). The remaining mis-shappeness I think is now just guiding jumps and jitters as described.

Thanks to Mick and Chris for the EQMOD Rate setting - not 0.2 use 0.5! Makes calibration of PHD a lot quicker too.

Full size image here (1.8Mb)
Here is the same crop as before:

[JohnP]

Wow Dunc - looks tons better - nice one. Bet you are feeling chuffed with that - John.

[Fay]

Great Duncan, I am going to reprocess mine now, as it does not look too good!!!!!!

[MarkS]

Duncan,

That's much better!  Those stars have a much better shape now.

Mark

[Carole]

That's definitely the best one.  The core is showing more detail and the stars are nice and round.

Carole

[mickw]

Much better Dunc

[RobertM]