HEQ5 RA and Date Setting Cirles… Are they necessary?

[deanen]

Hi All

 

I bought my first scope back in Mar this year and spent quite a bit of time researching how to use the HEQ5 and setting up the RA and Date circles to allow for precise positioning of Polaris. Once I received it, I spent even more time reading up on polar alignment (credit to Astro Baby, your guides on Polar Aligning the HEQ5 were a great help), but now I don’t quite understand whether setting the RA and Date circles are actually necessary for mounts with this new reticule.

 

As I’m sure many of you know, the position of Polaris is calculated by the Synscan HC based on user information entered at startup. All one has to do is place Polaris at the correct time on the clock face with 0 hr pointing up e.g. if at 22:00 this evening the HC positions Polaris at 9:30, all I would do is adjust the azimuth and altitude bolts to place Polaris at approximately 09:30 on the reticule.

 

I’ve had success polar aligning my mount just using the time calculated by the Synscan HC and don’t understand if the guides by Astro Baby are only relevant to the older polar scopes where setting Polaris’s transit time (using the RA and Date circles) offsets the polar scope and allows for polar positioning.

 

My gut feeling is that the guides only apply to older scopes, but if any of you knowledgeable ladies and gents know otherwise, please help me understand.

[vlaiv]

Yes, I believe so.

I polar align using EQMod utility, which pretty much does the same as handset and a bit more - it turns reticle so that 0h (or even any other selected major marked clock - 3, 6, or 9) is at correct position for Polaris at that given time and long/lat coordinates.

Only thing one needs to do is to make sure that 0h is at "noon" - or rather at top most point when starting procedure - this is because polar scope can be installed at any given orientation and 0h is not necessarily at "noon" when mount is at home/park position.

This is fairly easy to do - one places Polaris at dead center and only using altitude adjustment then moves Polaris at the top - after that releasing clutches and moving RA axis so that 0h comes to Polaris. That way 0h is at "noon" if mount head was level of course.

[Pain in the Neck]

Hi deanen

The first thing to say is that I am a complete beginner, but I am thinking the same way as you, in that the excellent Astrobaby guide is only relevant with the older HEQ5 reticle, where there was a little circle in which to place Polaris. My very recently delivered HEQ5 has the same newer reticle as yours, and I use the Polar Scope Align Pro app on my iphone to place Polaris at the clock position it states for the current time. I am no expert, but Polaris then seems to track around the circle quite happily, and I am basically ignoring the date setting circle completely.

I’m more than happy to be corrected by one of the many experts out there!

Charles

 

[Jiggy 67]

I use the setting circles for one purpose and one purpose only.....to set and save the perfect home position. The age of apps and other digital means has left them redundant for any other purpose 

[deanen]

On 05/08/2020 at 20:29, vlaiv said:

Yes, I believe so.

I polar align using EQMod utility, which pretty much does the same as handset and a bit more - it turns reticle so that 0h (or even any other selected major marked clock - 3, 6, or 9) is at correct position for Polaris at that given time and long/lat coordinates.

Only thing one needs to do is to make sure that 0h is at "noon" - or rather at top most point when starting procedure - this is because polar scope can be installed at any given orientation and 0h is not necessarily at "noon" when mount is at home/park position.

This is fairly easy to do - one places Polaris at dead center and only using altitude adjustment then moves Polaris at the top - after that releasing clutches and moving RA axis so that 0h comes to Polaris. That way 0h is at "noon" if mount head was level of course.

I've found this to be the same with my mount (recticle is ~ 30 degs west of north), but like you said as long as I place 0 at the noon position polar alignment works out just fine.

[AstroMuni]

On 05/08/2020 at 19:25, deanen said:

My gut feeling is that the guides only apply to older scopes, but if any of you knowledgeable ladies and gents know otherwise, please help me understand.

The setting circles can be used to help set the home position of the scope, but beyond that their use is only if you have a manual mount and use the RA/DEC circles to actually help point the scope.

I have written an FAQ for the newer reticle that you may find useful...

 

Edited August 10, 2020 by AstroMuni