What is the best way of using a polar alignment scope

[jstrandberg]

Howdy everyone! I recently returned to astronomy after several decades away.  I hope to be doing wide-field astrophotography using my Canon T3i and an assortment of lenses. As a platform for the camera I chose the EXOS-2GT mount.  The mount arrived last week.  My first experiments taking 45-second subs of Orion with my Rokinon f1.4 35mm lens, using just the motor drive after doing a rough polar alignment, were very encouraging.  In searching the internet for information on using the Bresser polar alignment scope, so I could get a more precise polar alignment, I happened upon Astro-baby's web sight and found some very detailed and easy to follow instructions -- and a link to this forum!  I have aligned the scope with the axis of the mount and am ready to do a polar alignment, once the clouds clear up. 

My question is this; there seem to be two methods of achieving a good polar alignment, Astro-baby's , which is the same as Bresser's explanation (although much easier to follow) and the Kochab alignment method.  So, what are the advantages of either method and why would you use one over the other?

I look forward to reading your responses.

[Demonperformer]

Hi, and welcome to SGL.

Unfortunately, I can't help with your specific problem as I have never been able to successfully use a polar scope (which resulted in me buying a polemaster - I am not recommending you do that if you are able to align with the polarscope)! But I'm sure that others will be able to offer assistance.

[kens]

Using a polarscope is hard work. Look up the DARV method for polar alignment. It is a drift alignment method suitable for use with DSLR. If you move to autoguiding (and you should if you  get serious about AP) then you can use PHD2 drift alignment or one of the other new polar alignment  tools in PHD2 (still in beta). Or you can use Sharpcap. 

[vernmid]

2 hours ago, kens said:

Or you can use Sharpcap

+1 for Sharpcap Polar alignment

[michael8554]

I would say that Kochab's Clock is for mounts without a polar scope.

Both mothods get your PA in the ballpark, but for serious imaging need refining with any of the many methods of drift alignment.

For wide angle imaging the various Polemaster type alignments suffice.....(runs to bomb shelter)

Michael 

[jstrandberg]

On 2/15/2018 at 00:41, kens said:

Using a polarscope is hard work. Look up the DARV method for polar alignment. It is a drift alignment method suitable for use with DSLR. If you move to autoguiding (and you should if you  get serious about AP) then you can use PHD2 drift alignment or one of the other new polar alignment  tools in PHD2 (still in beta). Or you can use Sharpcap. 

From the looks of it, without a telescope to magnify the image, I don't see how the image would be precise enough in the camera's view screen to be useful.

[michael8554]

20 minutes ago, jstrandberg said:

From the looks of it, without a telescope to magnify the image, I don't see how the image would be precise enough in the camera's view screen to be useful.

The DARV method uses an imaging camera attached to a telescope, and the image ideally viewed on a monitor, though using the magnifier on a dslr screen would do.

Michael 

[SteveA]

On 15/02/2018 at 07:41, kens said:

Using a polarscope is hard work. Look up the DARV method for polar alignment. It is a drift alignment method suitable for use with DSLR. If you move to autoguiding (and you should if you  get serious about AP) then you can use PHD2 drift alignment or one of the other new polar alignment  tools in PHD2 (still in beta). Or you can use Sharpcap. 

Clearly I don't get out enough these days.....I hadn't realised that Sharp Cap had a polar alignment feature ..particulaly as  I've  actually got the free version installed and run it before every imaging session to check my QHY5III guide camera is working, I never even thought to check out what else it can do.

Having just looked on line it seems like quite an interesting approach to polar alignment. For £10 I can't quite see why I wouldn't get a Pro license and see how it performs..

Steve

[Merlin66]

You don't need the pro version to use the polar alignment function.

 

[SteveA]

Yeah I noticed that the fee versions allows you to test this out....