polarizing the mount for Imaging

[neil groves]

I have 2 questions regarding this, one is can I polarize during the daytime for nighttime shooting to save me faffing around in the dark? and after I get a good polar fix, can I used that tripod mounting spot time and time again or do I need to polarize each time I set up? can I just mark the points where the tripod legs go on the ground and use those marks time after time?

Neil.

[Steve Ward]

1.  If you can't see Polaris you'll find that a tad difficult ... 'faffing about in the dark' kinda goes with the territory ...     

2. Yes , and I would advise you do so , I drilled three small holes in the patio just big enough to locate the tripod feet and now just 'plonk' the mount out in the same place each time.

Just make sure you don't adjust the tripod legs after getting things set up as you need alignment-wise.

[ronin]

Concerning 2 I would have said that reusing the locating spots again will make alignment quicker but I would not say that it would be a case of put it in the same spot and off you go.

Polar alignment for imaging needs the set up to be very accurate, this is often the reason that people build a pillar and set the whole thing in 2-3ft of concrete and perform a really accurate alignment and lock/fix everything. Even then it may be necessary to recheck the polar alignment occasionally - say every 6 months or annually. In effect with a pillar alignment and getting going may be 5 minutes, without nearer 20.

[baggywrinkle]

You need to align on Polaris.

If you use a compass and inclinometer in the day time the compass and inclinometer could be off by a degree or more quite easily.

One degree = 2 full moon widths which is a lot...Ok for visual but not for long time shots in AP.