I have mentioned before about using the South Polar Star for polar aligning (yes, there is one).
I thought I better explain it a bit better for people wanting to use it.
If you are fortunate enough to have Dark Sky, or if you get to observe or image at a dark sky site, this will greatly help you Polar align, making Drift alignment probably unecessary.
This is my method, and my GoTo's are almost dead centre every time at 6mm!!!!
Attach a green laser pointer to your scope.
Find a bright object (Sirius, Jupiter etc). Align the laser on the object while the object is in centre of the FOV in the scope. This step is to ensure the scope and laser are the same.
Now set the scope to ensure that it is locked perpendicular to the mount (use the setting circles if they are accurate). By using the Alt/Az adjusters only, point the laser at the South Polar Star (shown below). Look in your finderscope (I use binoculars coz there is a camera in my finderscope). Adjust your alt and az accordingly. Using the map below you will see which side of the pole star to place your laser to get exact SCP.
Check your monitor for an image like mine (shown below) and fine tune the mount.
You are now EXACTLY Polar aligned
As my mount is permanently polar aligned, I use this method to align the Home position before doing a 3 star alignment.
1. Taki's Map showing the the Pole Star. (coutesy of Taki's 8.5 mag Star Atlas)
2. Image on my screen with imaging camera showing the stars on Taki's map, and location of the SCP.
Good Luck
Last edited by ballaratdragons; 15-10-2007 at 09:33 PM.
I've pondered at star parties - get the best person at drift alignment to set up, then using a scope mounted green laser shine it at the SCP for 15 minutes to allow every other mere mortal to simply use the first mount's alignment to set for there own alignment.
I would spell your explanation out a bit more clearly - I was lost for a second seeing where the binoculars came in! Why not just use 50mm finder scope and a laser scope on the same OTA?
I would spell your explanation out a bit more clearly - I was lost for a second seeing where the binoculars came in! Why not just use 50mm finder scope and a laser scope on the same OTA?
I use the Binocs coz I have a security camera shoved in my Finderscope.
The reason for that is when I do my 3 star alignment I can sit in my control room and see on a TV screen what the Finderscope sees. Makes star alignment very easy.
You can use the Finderscope if you don't have a camera shoved in it.
Ken what you have suggested is certainly a good idea, and i can see how that may work, but the suggestion by Tech-Guru is also a great idea, both are winners to me.
Great idea Ken, i was trying this using just my binos and the finder scope. Will try with the laser.
For Star parties why not have a fixed permanent wedge like mount setup on the field that is accurately aligned. Then during the star party a laser can be mounted there to provide a reference.
Great idea Ken, i was trying this using just my binos and the finder scope. Will try with the laser.
For Star parties why not have a fixed permanent wedge like mount setup on the field that is accurately aligned. Then during the star party a laser can be mounted there to provide a reference.
Regards
Fahim
The problem with that idea, Fahim, is that to get exact alignment all the other people would have to be very near the line of the laser. Too far away and it isn't as accurate. But I know what you mean.
"Using the map below you will see which side of the pole star to place your laser to get exact SCP"
Er how exactly? You have two arrows - what does each signify? I was expecting only one where the SCP should be - which of the two arrows do you align to?
"Using the map below you will see which side of the pole star to place your laser to get exact SCP"
Er how exactly? You have two arrows - what does each signify? I was expecting only one where the SCP should be - which of the two arrows do you align to?
/still confused
The 2 arrows onscreen show the two stars with arrows on the star map. The large cross corresponds with the SCP cross on the map.
I tried to point out in the photo what is on the map.
This is as simple as I can get it.
I can't make it any simpler.
1. The whole area with everything marked
2. Exactly what I see in the FOV thru El-Cheapo 10x32 binoculars
3. Locating SCP in the 10x32 binoculars (point laser where green cross is)
I can see how this method gets your OTA pointing at the SCP but the precision of the mounts aligmenet will then be 100 dependant on the accuracy of your setting circles and the precision with which you can read them....I don't think this would be better than +-1deg would it?
I can see how this method gets your OTA pointing at the SCP but the precision of the mounts aligmenet will then be 100 dependant on the accuracy of your setting circles and the precision with which you can read them....I don't think this would be better than +-1deg would it?
Yeah John, you need to make sure (via setting circles or any other method you can devise) that your scope is perpendicular to the mounts polar axis. Then it works a treat, but this method is totally dependant on the scope being perpendicular.
Yeah John, you need to make sure (via setting circles or any other method you can devise) that your scope is perpendicular to the mounts polar axis. Then it works a treat, but this method is totally dependant on the scope being perpendicular.
I use this method after using the polar scope to fine tune.
To check that the scope is perpendicular to the mount I just look through the scope and pivot it in RA. Stars should just rotate in the field and not move off to the side. If they do you just correct the dec until they just pivot.
I use this method after using the polar scope to fine tune.
To check that the scope is perpendicular to the mount I just look through the scope and pivot it in RA. Stars should just rotate in the field and not move off to the side. If they do you just correct the dec until they just pivot.
