2 star alignment with DSC's

[Tiotion (Jack)]

Hi all,

After weeks of crappy weather i finally had a good oppertunity to try out my recently finished David Eks Box DSC. Im using two planetariums, Cartes du Cel and The Sky6 and my scope is a 12' GSO dob.

I haven't been able to get the alignment quite right; the best was about 2 inches from where i was pointing to where The Sky was telling me i was...worlds apart... So any tips on performing a good 2 star alignment? Time set is accurate to the millisecond, co-ordinates are from google earth pointing to my backyard. I'm using Shaula and Achernar as my alignment stars. Are there better stars to align on?

Are the encoders installed correctly??? I have them through pivots the previous owner had installed to use his Argo Navis through. The encoder shaft is inserted into these pivots and held tightly with grub screws. They are then mounted on brackets with a little nut, which are tightly fixed to my mount with wing nuts.

When moving between targets should i move the scope very slowly, or just normal pace is fine? I have 30, 20 and 5mm eyepieces and i use the 20mm. Should i use the 5mm?

Any tips would be very helpful! Looks like a clear night tonight!

[mental4astro (Alexander)]

There is a very good and EASY way to two star align.

1: Use your 20mm

2: Defocus your star of choice until its image nearly fills the ENTIRE field of view- this will make centering it nearly impossible to stuff as it is the only thing in the field of view

3: Go through your alignment proceedure with the DSC

4: Repeat with a second star, even a third

5: Replace the 30mm eyepiece and try the alignment out on a target of choice, and be ready for a pleasent surprise.

Another thing that helps is to choose a second star that is quite far away from the first. These processes go to reduce error which is what most causes errors in alignment.

Mental.

[Archy (George)]

Originally Posted by mental4astro

There is a very good and EASY way to two star align.

1: Use your 20mm

2: Defocus your star of choice until its image nearly fills the ENTIRE field of view- this will make centering it nearly impossible to stuff as it is the only thing in the field of view

3: Go through your alignment proceedure with the DSC

4: Repeat with a second star, even a third

5: Replace the 30mm eyepiece and try the alignment out on a target of choice, and be ready for a pleasent surprise.

Another thing that helps is to choose a second star that is quite far away from the first. These processes go to reduce error which is what most causes errors in alignment.

Mental.

Defocusing: that a good suggestion. I'll try it