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Old 29-01-2009, 10:31 PM
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spearo (Frank)
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spearo is offline
Join Date: Feb 2006
Location: Braidwood (outskirts)
Posts: 2,281
Hi Deception,

Not sure why you wouldn't use a mask.

While the Bahtinov mask does take time to make yourself (free) you can whack togehter a super cheap and effective "emergency field Hartmann mask" in a matter of 2 to 4 minutes (seriously I've done it several times including recently for a friend who came to visit with ihs scope.

I'd also use this in combination with Live view, especially if this camera offer additional functions in the bulb range of magnification (the 20Da does)

Nevertheless, take any piece of carboard (rip out a side from any carboard box) that can fit over the aperture of your scope, cut to a rough circle bigger than aperture and leave a couple of flaps that can be bent so the tig doesnt slide off the front of your scope.
Cut out 2 circular holes opposite ends of the circle (or 3 in a tringular arrangement) about the size of a can of Coke (product placement - not...i just like it with my Rum...) for your 8 and 10 inch scopes or about the diameter of a 20 cent piece for your 100mm.

looking into your liveview, adjust focus until the multiple (2 or 3) stars merge into one.

Of course this can be improved by spending more than 2 minutes on the whole process but this is very quick and easy, free and you can pop out as many of these as you have cardboard at home!
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