EQMOD - PolarScope Alignment Tool

[Interested]

I have just set my mount up to use EQMOD. Regarding the PolarScope Alignment Tool instructions, they mention a 'subsequent set-up procedure'. Does this mean I need to do a Polar alignment each time I use the mount?

I have a permanent setup so would have thought that, once I have carried out an initial Polar Alignment, unparked, carried out a goto alignment (minimum of 3 Stars, slew using (in my case)) Cartes du Ceil, syncing with each Star (after centering on each Star using the EQMOD slew buttons), then I could do my imaging session, park the scope at the end of the session using the EQMOD 'park' button and, on the next session, just 'unpark' and 'goto' my desired target? Phew!

Also, is the 'sync' information automatically saved and used next time, or do I have to load the sync file each time?

Sorry if the question seems simplistic.

Many thanks for any help.

Regards,

[Bizibilder]

If you have a permanent set up then you only need to do the PA once (and maybe occasionally if you feel that something has "moved"!).  The sync info is saved but I always switch on and slew to a bright star, align and then sync again.  A couple more bright stars well spaced will give you a couple more alignment points and you can goto from there.  Once you are familiar with the system you can do the 3 point align in far less time than it has taken to type this!

I usually slew to the first bright star and then focus using a Bhatinov mask and then goto my target ready to start imaging.  Same applies for visual work.

[Interested]

Thanks for your reply Roger. That really answers my question well

One other question, lol: the PolarScope Alignment tool has two small circles on the outer circle, a red circle and black circle close too it. Using Polar Finder, it would appear that Polaris is better aligned using the black circle, but what is the black circle there for?

If it's there to confuse me.......it worked!

Regards.

[Bizibilder]

I'm pretty sure it only has a red circle!  Two to be precise - the "large" one that has the "small" alignment circle on its circumference.  You place polaris in the little circle.  I suspect the black circle is an optical effect maybe caused by not looking straight through the polar finder scope or similar?  It is quite difficult and awkward to look through!  Another possible explanation for the black circle is that your polar scope is too brightly illuminated and your eye is playing tricks on you by giving you a ghost "black" image?

[Interested]

On my computer I have clicked the Pole Star HA button in EQMOD to bring up the PolarScope tool where you set the 6 o'clock/12 o'clock position/ PolarScope Home etc. On the face in the PolarScope tool I can see the small red alignment circle, and a black circle (the same colour as the segment lines) close to the red circle. It is the same size as the red circle and It cuts the red circle by 50% and Polaris is sitting on it?

[Tinker1947]

Getting the PA setup on my mount, i used the handset PA align option, do a 2 star align this allows when successful the PA option in the handset, using your RDF or Finder scope to align saves getting down to look through the Polar Scope, i then Park the scope then repeat the 2 star align and then the PA using different stars...my guide scope is a ST-80 with a Lodestar CCD, this is aligned so the PHD bullseye centre is aligned with the centre of my DSLR Sensor, this allows the adjustments of the bendy bolt from a sitting position while the alignment star is centred on the PHD screen....THis may be doable in EQMod not got round to trying yet...

[Interested]

I took a photo to illustrate:

[Bizibilder]

Looks like they have upgraded the PA routine!

[chrisshillito]

The vixen/synta reticule display has been in EQMOD for years!

The purpose of the darker circle is to illustrate the effect of precession (many folks know the reticule is out of date but most don't know how much/little of an effect this has). if you were using the polaris hour angle as provided by the synscan handset (which doesn't take into account precession) then the reticule would be in the darker position and you would have to position polaris where the white dot is. EQMOD of course does precess the polaris position which is why the reticule is correct with regard to RA - precession in DEC i why the polaris dot is further towards the centre.

Chris.

[Interested]

Chris,

Thank you for the explanation. I'm still new to EQMOD and couldn't find the reason for the two circles. Know I know .

I synced on 4 stars this evening and then slewed to the Rosette Nebula. It was bang on!

Just need to figure out why PHD won't start calibration now! Have chosen 'on Ascom' and the guide camera is working ok, green box comes up, but that's it! Frustrating

[Bizibilder]

Thanks for the correction!  Maybe I should have looked rather than rely on memory.

[Geordie mc]

Might be wrong here, but think you can force PHD to calibrate by holding shift as you start the guiding. With eqmod it will pulse guide so no need for an st4 cable. Think there is a properties box associated with the as com setup where you choose eqmod or eq 5/6 sorry can't remember more without setting things up. Been a few weeks and I'm getting old lol.

[Interested]

Thanks for your input Geordie.

Think I am all setup now. Carried out the PA using EQMOD, and, using Stellarium, now have several 'N-Points' recorded.

Needed to go into the N-Point screen in EQMOD and select 'save' and, 'load on Startup' as these boxes weren't selected as default.

I am using PHD2. For Pulseguiding I select 'EQMOD ASCOM EQ5/6 for 'Mount'. For ST-4 guiding I select 'On-camera' and use an ST-4 cable between the mount and guide camera (QHY5).

Regards,

[Geordie mc]

There is a manual control in phd2 that you can use to test that guiding is reaching the mount. Use the sorrow keys and listen to hear rather than see if the signal is going to the mount. Might be worth a try.

[Interested]

Found it! In the Tools drop-down list/ manual guide. That's a useful tool to ensure mount and PHD are talking to each other. The more I see of PHD2, the more I like it

On my wish list would be a 'test' mode whereby you could try guiding during the daytime, rather than have to wait for a clear night to find guiding problems.