Re: Tracking w/ Passil 4 polar alignment

Christopher Erickson

Depending on the lens focal lengths, personally I have found polar alignments with a PASILL4 to be more than accurate enough for astrophotography with SLR's ranging up to 30 minute exposures for wide fields.

Could be flexure someplace. If both cams show the same defects then it is something they both have in common.

Long cam lenses can exhibit a lot of flexure and sag, depending on how and where they are attached to the plate. And on their design and quality.

Turn off image stabilization too. It often has trouble with very dim scenes. And turn off autofocus, of course.

I hope this helps.

-Christopher Erickson
Observatory engineer
Waikoloa, HI 96738

On Tue, Jul 21, 2020, 7:59 AM Wiggins, Rick <rickwiggins@...> wrote:
Hi Roland,
I did setup using the pasill4 polar scope and got good alignment on the two stars through the polar scope. I did not use a PE curve. Do you think slight smearing in 25 secs given that rough setup is reasonable or should it be better?
Thanks, Rick

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