Drift aligning your mount part 2

Following on from my last post on this subject I have given it a good try out and it works really well with a few changes. Because I am dyslexic I hate anything that does not explain how it is done in an easy-to-understand way so hopefully, this will be clear enough.

First, make sure your camera is focused on a bright star using a bahtinov mask and live view, and then do a quick polar alignment with your polar scope.

Next, we move the telescope so that it is pointing to the east and at a star just above the horizon the lower the better. I then center it in the live view and set the camera to take a 30sec shot at whatever ISO gives you a clear image 800 is usually ok. My slew setting was x16 for this movement.

Now start the image going and leave it for the first 10 seconds at 11 seconds hit the direction button on your mount control so it moves east at 21 seconds hit it so it moves west and then keep it moving till the exposure is finished. So ten seconds not moving ten seconds move east ten seconds move west. 

When I tried it I got an image like this you can see the star ends up just below where it started off so I made some adjustments to my azimuth bolts and looked at it again to see if the v was getting wider or smaller it got wider so I simply went in the other direction with my adjustments until the star went perfectly back on itself forming a straight line which you can see in the second image.

This will give you an image of the star moving east then back and any error in your azimuth will show up as a v shape. So just adjust the azimuth bolts on your mount and repeat until you have a star that goes right back over itself in a straight line and then your azimuth setting will be correct.

Now we move on to correcting the altitude of the mount. This time we chose a star low down in the south. And repeat the whole procedure.

Check again and when they both produce a straight line with no v shape you will be polar aligned.

Remember: star in the east low down to sort out your azimuth, star in the south low down to sort out your latitude. Don't worry too much about which bolt to adjust direction in just make an adjustment and note which way the v is going if it is getting wider go the other way if it is getting closer together keep going the way your going.

It is a pretty good way of getting polar aligned and fun to try out but there are many other factors that can make that alignment less than perfect which all need checking these include a good colmination of your telescope so that the mirrors are lined up correctly or your stars will have an egg shape to them. Also, make sure your gears on your mount do not have slack in them and tighten up any bolts that need adjusting.

Like many things in this hobby it requires patience and determination to get right so if you don't succeed first-time don't be disheartened keep trying and keep a good notebook of your efforts or better still a blog like this one which has really helped me keep track of my progress over the years.

Clear skies and hope that helps you out.