Polar Alignment - The Key to Great Tracking!
Using a very accurate mount like the AstroTrac TT320X isn't a guarantee in itself that your shots will be perfectly tracked.
You need to ensure that your mount is correctly aligned with the sky, or ‘polar aligned’, to unleash its full potential. The AstroTrac polar scope makes polar alignment a quick and easy process.
The polar scope’s precision glass reticule is marked for alignment with stars in the northern and southern hemisphere. In the northern hemisphere, the polar scope is aligned on Polaris and an optional additional two stars. In the southern hemisphere, the polar scope is aligned on Epsilon Hydri and an optional additional two stars in Octans - Sigma and Chi Octantis. The TT320X Instruction Manual gives full details of the polar alignment procedure.
Easy to Use in The Dark
There is nothing more annoying than trying to aim a red torch at precisely the right angle down the polar scope tube without blinding yourself with red light. The built in illuminator shines red light onto the reticle markings helping you get polar aligned quickly and easily.
The red LED is powered by two small LR41 buttons cells ensuring there are no wires to snag in the dark.
Quick to Setup
The TT320X’s unique fold away polar scope arm enables you to position the polar scope clear of your equipment with sight of the alignment stars in the sky.
For accurate polar alignment, the polar scope needs to be held parallel to the axis of rotation of the TT320X. The AstroTrac polar scope is secured flush with the polar arm by powerful magnets ensuring perfect alignment and ease of rotation.
How Accurately do I Need to Polar Align?
The accuracy of your polar alignment depends on the following factors:
- Focal length of your lens or telescope
- Camera exposure time
- Position of your target in the sky
If you are shooting large, relatively bright objects, such as the Milky Way, aurorae of constellations, you don't need to polar align as precisely as you do for smaller, dimmer targets, which you would shoot with a telephoto lenses or a telescope.
How do I Polar Align During the Day for Tracking the Sun?
There are two options available to you for polar alignment during the day when its too bright to use stars:
- Align the night before with the polar scope,
- or, use a compass and latitude scale to polar align during the day
Your AstroTrac needs to be pointing true north. Hold your compass square against the AstroTrac and adjust in azimuth until the compass needle indicates magnetic north. Don't forget to allow for magnetic variation by adjusting your compass bezel first. You can find the correction on most maps or by searching on the Internet.
You also need to have your AstroTrac angled so that the angle it makes with the horizontal corresponds to your latitude. For example - if you are at a latitude of 52 °, the TT320X will need to be angled at 52° to the horizontal.
Provided your tripod is level, you can use the latitude scale on your tripod head or alternatively you can use a plumb line and protractor held against the underside of the TT320X.
Can I Use My Existing Polar Scope?
The TT320X's unique magnetic polar scope system requires a specially made metal washer to be pressed onto the polar scope. These washers are manufactured specifically for the AstroTrac Polar Scope and won't fit other makes.
|Weight ||0.13 kg (0.29 lb) |
|Length ||150mm (5.9 inches) |
|Barrel diameter ||35.00mm (1.38 inches) |
|Replacement batteries ||2 x LR41 or equivalent |