The Vixen Polarie camera mount - an evaluation.
I had a request on Google+ today to evaluate the Polarie startracker camera mount. I responded by writing that so far I have not achieved fully accurate polar alignment (using compass and level) but that I hope to next time out, now that I have bought the polarscope.
Exposure times are limited by the accuracy of alignment and the direction of view. Longer exposures at zero declination i.e. South Celestial Pole(SCP) than at 90 declination (Celestial Equator).
Bearing in mind that the manufacturer only markets the Vixen Polarie for wide-angle imaging, I am getting considerable trailing on images taken with a 200mm lens and to a lesser extent with a 135 mm lens. In many cases the trailing is only obvious by zooming and the results are mostly reasonable - but it will be nice to eliminate that. So far I have achieved up to 3 minutes with a wide angle lens but less than thirty seconds with a 200mm looking at declination zero. However, a friend in the Society already uses a Vixen polarscope and is achieving much longer exposures than I have so far, so there is hope for me yet.
Canon 60D on Vixen Polarie camera mount, with Vixen Polarmeter attached.
Do I like the Polarie? It has opened up a different area of observing for me and I've left the telescope indoors for several months. The biggest problem is the clouds - that may sound a bit obvious - but with a wide angle camera I have learned that it is harder to avoid the clouds than with a telescope pointing at a small area of the sky.
I believe the Polarie will become extremely popular. It is a very good quality product, well engineered and gets good results. If you already own a dslr, then it would represent good value. It needs a sturdy tripod and I bought the manufacturer's model. I then went on to purchase the polarmeter (an excellent level and magnetic compass with a declination setting). Now that I have just recently also bought the Vixen polarscope, I feel that no further expenditure is required and I ought to be able to produce some good images. Provided, that is, that I can find the four magnitude five stars in Octans to align with.