Interesting Experience With PHD

[leon]

Good morning to all.

Well last night I decided to get up at 1am and capture this Small Mag Cloud, you know the one that I only got half of the night before, I will post it as bit later.

Anyway, everything was fine, the scope was humming away, and the focus was right, so now to get it guiding, opened up PHD, did the usual stuff, found the star that I wanted and clicked the icon to get it to calibrate.

I waited and waited, and then it told me in no uncertain terms, CANNOT CALIBRATE ON THIS STAR, NOT ENOUGH MOVEMENT, Ok I thought, I must have done something wrong, and started it from scratch, but again it told me it couldn't calibrate because the Star was not moving enough.

Figuring there was something wrong with the scope, I checked it all out and all seemed fine, tried many more times, but still the same response, from PHD.

Bugger, I was not to waste this early morning, had lost an hour anyway with daylight saving.

I then stopped the whole set up and slewed it around a bit and found another Star, the smallest I could get, surly there will be movement in this little bugger.

As it turned out, it locked on and stayed there all night, perfect guiding, but I also found that the numbers and stuff that one can see flash up periodically were very few and far between, but this happens most times when guiding, I seem to get very little movement once I have a Star locked in.

Am I to assume that it wasn't getting much movement because the mount is pretty well spot on to the South Pole, and/or would the fact that the SMC is pretty close to the pole, with slower movement than straight up, or maybe a combination of both, I would be interested to know.

Leon

[pvelez (Pete)]

Leon

I just upgraded my LXD75 to an EQ6. Trying out PHD last week, I couldn't get the star to move enough as well. Turns out that I hadn't clicked on the mount icon each time I went to recalibrate (eg after adjusting the balance). With the LXD I didn't need to do this as the connection with the mount seemed to stick. So PHD was waiting for the mount to move the scope but as the mount wasn't connected, the only movement was from lousy polar alignment.

Not sure if you had the same issue.

Pete

[[1ponders] (Paul)]

Being so close to the SCP Leon it is possible you didn't get enough movement. What are your calibration steps set too (I use 500 normally, maybe try longer closer to the pole)? What was your guide rate set to (I find .3x sidereal not enought close to the pole and use .5x sideral)? Are you sure you weren't trying to guide on a hot pixel. It's happened to me before.

[leon]

Pete, I really don't have much of an issue with it at all usually, and nothing has changed from the last times that I have used it.

It was a dead calm night, and my set up always performs better with the scope on the East side and the counter weights on the West side, which was the case last night.

Maybe there was not enough error and movement in the gears, so PHD assumed that the star was not moving.

Anyway, it all works well now so I'll be buggerd if I know what caused this.

leon

[leon]

Ok Paul now you have got me thinking, to be honest I don't usually change much of the settings, I just find my guide star, and put the mount in Photo mode and Run PHD, which always seems to work fine, It was just last night that it did not want to fire up.

And this hot pixel as you speak of, i'm sure that is possible too, but now I suppose I will never know this, but will keep it in mind, if this occures again.

Many thanks for your response.

Leon