Who needs meridian flips anyway?

[lukebl]

I've just been processing some images from a couple of nights ago where the target crossed the meridian, and I just let it carry on without a meridian flip. I realise that some of them were captured with the target 4 hours past the meridian, and and guiding was still perfect with 15 minute exposures.

Meridian flips are just so much unnecessary hassle!

 

 

 

[Dave Smith]

I would agree there is no need to be paranoid about a meridian flip. The only danger to look out for is the scope crashing into the mount.

Dave

[coatesg]

49 minutes ago, lukebl said:

I've just been processing some images from a couple of nights ago where the target crossed the meridian, and I just let it carry on without a meridian flip. I realise that some of them were captured with the target 4 hours past the meridian, and and guiding was still perfect with 15 minute exposures.

Meridian flips are just so much unnecessary hassle!

 

Yes, though kinda a necessity when the scope is about to crash into the pier... (or hopefully reaches the safety limit and stop tracking before that!)

[Stub Mandrel]

Agreed! At home meridian flips are a pain as I can only go an hour or two past the meridian anyway. If my camera hits the tripod it means the scope is pretty much pointing at a tree...

[ollypenrice]

Usually it's possible to go for longer after the flip when shooting at low elevations. At high elevations the camera end collides with the pier much earlier. I certainly have no problems going to the mounts' physical limits when possible. On occasion, though, near the zenith with a long refractor, there can be a short spell when I can't reach the object at all on either side. That's annoying!

Olly

[glowingturnip]

I have to admit I'm very lazy with meridian flips - I've had my weights sticking up in the air on several occasions !

 

[carastro]

Agree with all the above.  I frequently go well past the Meridian and only flip when I really have to i.e. when camera or filterwheel or scope is about the hit the tripod/pier.  Though if I am going to be imaging for a fair few hours yet and know I will have to do a flip at some point in any case, then I will just do it to get it over with.

Carole 

[swag72]

I have my meridian flips automated in SGP...... if I had to do them manually I'd avoid them like the plague ?

[carastro]

Quote

 I have my meridian flips automated in SGP...... if I had to do them manually I'd avoid them like the plague 

 

You must have everything working very well Sara.  Either you have no cone error or you have plate solving that would automatically make any corrections.  If I do a Meridian flip I always miss the target on the 2nd side, so I have to go back to park and do a new alignment.   I am however trying to get Plate solving and EQMod into my work flow, but I doubt it will happen automatically.  

Carole 

[RayD]

SGP automated meridian flip for me also.  20 minutes past meridian maximum, and wait for flip.  Plate solve and auto-centre to get things back to where they should be.  All done often whilst I am blissfully sleeping  ?

Here's a video of mine taking place:

Meridian Flip - SGP

[swag72]

15 minutes ago, carastro said:

You must have everything working very well Sara.  Either you have no cone error or you have plate solving that would automatically make any corrections.  If I do a Meridian flip I always miss the target on the 2nd side, so I have to go back to park and do a new alignment.   I am however trying to get Plate solving and EQMod into my work flow, but I doubt it will happen automatically.  

Carole 

SGP platesolves after the flip then puts the mount in the right place..... it's never in the right place after the flip but the plate solve sorts it.

[tooth_dr]

I'm one mouse click away from ordering SGPro.  Does it automatically pick up PHD again?

When I manually do a meridian flip PHD never works properly after, it just runs away on the dec axis.  I've checked reverse dec on flip and I've went into the data calibration and no joy.

So ultimately it means either staying up late to do the flip as soon as possible, or going to bed, and getting up 2-3 hours after meridian crossing and then flipping.

[carastro]

Quote

I'm one mouse click away from ordering SGPro.  Does it automatically pick up PHD again?

When I manually do a meridian flip PHD never works properly after, it just runs away on the dec axis.  I've checked reverse dec on flip and I've went into the data calibration and no joy.

So ultimately it means either staying up late to do the flip as soon as possible, or going to bed, and getting up 2-3 hours after meridian crossing and then flipping.

Do you do a new calibration after the flip?  

I tried SGPro once when I had the trial version, but I could not get SGPro to connect to PHD2 even had an expert IT person trying to get it to work, so gave up.  Maybe it was my laptop that was the problem as every-one else seems to get along with it OK.

Carole 

[tooth_dr]

2 minutes ago, carastro said:

Do you do a new calibration after the flip?  

I tried SGPro once when I had the trial version, but I could not get SGPro to connect to PHD2 even had an expert IT person trying to get it to work, so gave up.  Maybe it was my laptop that was the problem as every-one else seems to get along with it OK.

Carole 

Yes I do a new calibration after a flip, cant seem to get it to work otherwise.

[RayD]

6 minutes ago, tooth_dr said:

I'm one mouse click away from ordering SGPro.  Does it automatically pick up PHD again?

When I manually do a meridian flip PHD never works properly after, it just runs away on the dec axis.  I've checked reverse dec on flip and I've went into the data calibration and no joy.

So ultimately it means either staying up late to do the flip as soon as possible, or going to bed, and getting up 2-3 hours after meridian crossing and then flipping.

Yes.  If you look at my video I linked you will see it pause PHD2 and then start it up again after the auto-centre.

[swag72]

There's a tick box in PHD to allow the calibration to flip after the meridian...... so no need to recalibrate. In SGP you can tell it to recalibrate on target change, not sure if that works for a flip...... but with the PHD box ticked it all takes care of itself ??

[carastro]

I have to admit to being a bit of a dinosaur and am still on PHD1, maybe there is something different on PHD2, which I have installed but never use it. 

Carole 

 

 

[tooth_dr]

10 minutes ago, swag72 said:

There's a tick box in PHD to allow the calibration to flip after the meridian...... so no need to recalibrate. In SGP you can tell it to recalibrate on target change, not sure if that works for a flip...... but with the PHD box ticked it all takes care of itself ??

I have this box ticked, but I’ll try again.   So far it doesn’t work 

[DaveS]

Theoretically the ASA "Sequence" program should automatically take care of any flips, but ATM keeps throwing a wobbly, I think due to a C++ library error. One of the joys of encoder guiding, no loss of guide star and no re-calibration. I have (Or had, will have to re-do at my new location) a 120 point plate-solved all-sky model which takes care of systematic errors, and a local model to refine it for the particular imaging run. When I've manually flipped the target is close to the cross-hairs, so only needs minor tweaking, and another local model, which takes no more than 5-6 mins to do.

[tooth_dr]

22 minutes ago, RayD said:

Yes.  If you look at my video I linked you will see it pause PHD2 and then start it up again after the auto-centre.

Thanks Ray. Just watched it. Feel confident trying it now.

Does PHD just auto select a new star after the flip?

[swag72]

Just now, tooth_dr said:

 

Does PHD just auto select a new star after the flip?

Yes

[tooth_dr]

3 minutes ago, swag72 said:

Yes

Thanks.