2 star align or auto guiding set up

[Kelly Wilson]

Good morning

i have a simple question to ask and it might seem stupid but I’ll ask anyway.

when I set up for the evening what is the best procedurepolar align; 2 star align, calibrate stars then set up auto guiding with PHD or auto guiding first?

thanks

kelly

[Anthonyexmouth]

for me I 

1. PA

2. Calibrate PHD2

3. Align with last star close to where i'm imaging 

4. Go to target and start guiding

 

but i could be wrong

[Marky1973]

I do the following

1. PA

2. Connect scope etc and 2 star alignment

3. Slew to star close to target and re-enter with synscan

4. Slew to target and centre

5. Calibrate PHD2

6. Start guiding.

(I might even focus somewhere along the line if I remember!?)

I like to calibrate PHD2 once I am on target and have selected a guide star, although I have no idea if that makes any difference! ?

[Gerry Casa Christiana]

I do the same as above but 3 star alignment but around the object I would like to image. I believe it helps with cone error. 

I would say though if numbers are good in PhD just start imaging I think we waste too much time fiddling or at least me which I enjoy too much. 

Gerry

[Z3roCool]

I used to:

• PA
• Star Align
• Calibrate PHD
• Guide

Now:

• PA
• Calibrate PHD (PHD always moaned that I was calibrating too close to far North or near Equator on some targets- think that is just because it is looking at old data?)
• Star Align (Near Target) - Now use Plate Solving also)
• Guide

[Anthonyexmouth]

1 minute ago, Z3roCool said:

I used to:

• PA
• Star Align
• Calibrate PHD
• Guide

Now:

• PA
• Calibrate PHD (PHD always moaned that I was calibrating too close to far North or near Equator on some targets- think that is just because it is looking at old data?)
• Star Align (Near Target) - Now use Plate Solving also)
• Guide

thats why I calibrate first too. I also platesolve my star alignment, just keeps adding sync data whenever i change target. 

[Kelly Wilson]

Thanks for the great advice.

at present I will 2 star align the calibrate 4 stars are you all saying I no longer need to do this?

current set up

William Optics Zenithstar 73

williams optics flat 73

Altair Astro Hypercam 183m

Alair Astro GP Cam V2

celestrin AVX Mount 

regards

[MarsG76]

On 03/09/2018 at 19:56, Marky1973 said:

I do the following

1. PA

2. Connect scope etc and 2 star alignment

3. Slew to star close to target and re-enter with synscan

4. Slew to target and centre

5. Calibrate PHD2

6. Start guiding.

(I might even focus somewhere along the line if I remember!?)

I like to calibrate PHD2 once I am on target and have selected a guide star, although I have no idea if that makes any difference! ?

+1

 

[tooth_dr]

I too calibrate PHD once completely lined up and ready to image. I just thought this made more sense, but I'm always open to new ideas!

[ollypenrice]

Chorley! My old home town - but I do mean old!!!

Back to business, think from the top down.

1) The mount needs to be polar aligned to a decent degree whether guided or not, so do that first. This has nothing to do with your Go To calibration. There are all sorts of ways of doing this but the DARV method is quick and software-free, which means reliable. https://www.cloudynights.com/articles/cat/articles/darv-drift-alignment-by-robert-vice-r2760

2) If you are a mobile imager and are not aiming to do very long subs ( longer than five to ten minutes, say) you don't need a high-order polar alignment. A bit of misalignment will give you natural dither.

3) Your GoTo really only needs moderate precision if you are going to spend the session on one target. (Shooting several targets a night is something I'd consider a mistake, personally.) So if you do a one star Go To calibration on a star close to your target you should get there OK. I would then note the RA and Dec co-ordinates of your final choice of framing on a bit of paper so that if things go belly-up you can go back quickly.

4) Then you light up PHD and ask it to calibrate your guiding.

Olly

[RichLD]

My 2 cents FWIW ?

• PA using Polemaster
• Initial focus check on Polaris with Bahtinov Mask (my FOV is generally around 6x4 degrees so I don't have to slew anywhere)
• Slew to target and plate solve (I use the SGP Framing and Mosaic wizard)
• Recheck focus on target using Bahtinov Mask
• Choose guide star in PHD2
• Calibrate PHD2 and start guiding, allowing a couple of minutes for the guiding to settle
• Start imaging

Like some others here I believe it prudent to calibrate PHD2 on or near your target, seems to make sense to me

[fireballxl5]

1 hour ago, ollypenrice said:

Chorley! My old home town - but I do mean old!!!

do you guys listen to Chorley FM lol!

[Pompey Monkey]

1. Polar align *I don't do this because I have a permanent mount.

2. Platesolve.

3 goto target, using platesolve.

4 Focus, PHD. Image.

[Anthonyexmouth]

Does having a permanent mount mean there's no need to calibrate PHD every night. 

[Pompey Monkey]

23 hours ago, Anthonyexmouth said:

Does having a permanent mount mean there's no need to calibrate PHD every night. 

Pretty much.

However, recalibration is absolutely needed if the guidescope is rotated or if too much fettling has been done to the setup.

Sometimes I find that it's beneficial to recalibrate after a meridian flip, but that's more to do with the backlash/balance in my setup.

On the other hand, it only takes a few minutes, so I do it occasionally just for my own peace of mind

[Anthonyexmouth]

4 minutes ago, Pompey Monkey said:

Pretty much.

However, recalibration is absolutely needed if the guidescope is rotated or if too much fettling has been done to the setup.

Sometimes I find that it's beneficial to recalibrate after a meridian flip, but that's more to do with the backlash/balance in my setup.

On the other hand, it only takes a few minutes, so I do it occasionally just for my own peace of mind

Yeah, of all the things to to when setting up calibration is the easiest. Usually set it off and thats the time to grab a coffee for the real fun to begin. 

[tooth_dr]

23 hours ago, Anthonyexmouth said:

Does having a permanent mount mean there's no need to calibrate PHD every night. 

I still calibrate every time even though I am permanently set up. I’ve had no success with flipping the calibration after a meridian flip. So typically I’ll image before the flip, then go out and flip it and recalibrate phd. Be nice to automate this someday.