quick PHD question

[msinclairinork]

Hi

Do you have to re-calibrate everytime you move to a new object?

Thanks,

Michael

[Merlin66]

Not sure... but I do anyway. Only takes a minute then there's no ambiguity.

[msinclairinork]

thanks for that.

It did take quite a while for me last night (first time) took about 10mins? around 50 steps each way?

Sounds like I might have to adjust some of the default settings. But it was doing its job for at least 8 min subs so was happy with that.

Thanks

Michael

[shaunster]

yes you do and you should aim for about 20 steps, 50 is far to many

[msinclairinork]

ok....what should i do change that?

[Digz]

Thats interesting.

I must admit at present I haven't been recalibrating between objects, no particular reason either. As Merlin66 says it doesn't take long, guess I should start doing it.

[Starflyer]

Hi Michael,

You need to go into the brain config and increase the calibration step setting. This setting determines the length of each pulse that is sent during calibration. Long focal lengths need a lower setting and shorter focal lengths a longer setting.

As you've already determined that it did 50 steps and 15 to 25 is ideal, try doubling it, or slightly more if you want a shorter calibration time.

It's a good idea to do the calibration (and guiding) at at least 2 seconds exposure to prevent chasing the seeing unless the seeing is particularly good in your location.

If you change targets from one side of the meridian to the other you will need to recalibrate. I always recalibrate when changing targets by more than a few degrees, it takes a couple of minutes and I know it's going to be right.

Cheers,

Ian

[Merlin66]

I agree 50 steps is too much - 25 is a "limit"

[msinclairinork]

Thanks for that Ian,

Will give that a go next time.

Michael

[Fay]

Michael, I always have a problem with 50 steps & then PHD gives up, if I am near Polaris, saying star not moved enough.

I then slew to somewhere in the SE & then go back to my subject. It has always been ok. I may calibrate & then go to another couple of objects in different parts of the NE, E, SE, & guiding is always ok.

Fay

[msinclairinork]

I have to say it was guiding really well, no issues at 8mins any way?

But it did take a long time to calibrate so I will make the adjustments mentioned and hopfully that will speed things up.

Thanks,

Michael

[Sparrow]

I don't always re-calibrate - particularly if moving to another object in the same part of the sky. Normally it resumes guiding quite happily - if not, then I do a re-calibration.