|
If you want to polar align it, you can't because the mount that you have it on is an alt-az mount. It can track in altitude (declination if you will) but not in right ascension, which means it can't follow an object across the sky in sync with the Earth's rotation. That's why if you try and go for longer than 30secs to a minute with any exposures, you will see the stars in your pictures begin to rotate. That is due to those stars moving in RA across the line of sight of your scope. In order to be able to take long exposure shots, you need an EQ or equatorial mount, which will also track the stars in RA, allowing you to lock onto a star and follow it across the sky in sync with the Earth's rotation.
The Moon and the planets, because they're bright, can be imaged quite quickly, without any trailing occurring. Having your scope on an alt-az mount in this case doesn't really matter. But to try and get a photo of anything else but the very brightest of DSO's (Deep Sky Objects) will only result in disappointment. That's why an EQ mount is essential for that type of photography.
The only way you could get around it would be to buy a field derotator. They're not cheap and unless they're top quality you will not be able to run exposures for more than a couple of minutes at a time. They need to be very accurate and your mount needs to be accurate also in its pointing ability.
|