Re: [APML] ST-4 question

[jeff allen <jeffstak@yahoo.com>]

Jerry thanks for the reply.

I put in a couple extra screws to hold the guider,
I'll look at putting in another focus lock, but the
focus tube seems pretty tight even without being
locked.

As for the varying brightness. I never saw that much
variability while using the Tak FS-78 over the last 2
years. Maybe it's just been the seeing. Maybe it's
been the diference between focal lengths (f/8 and
f/11) and seeing. If the guiding is good on my last
pics, then I'm not going to sweat it.

Thanks,
Jeff

--- Jerry Lodriguss <jml@astropix.com> wrote:

> Perhaps it needs two lock down screws. The focus
> tube can pivot and move 
> with one lock down screw (and the other point of
> contact at the rack and 
> pinion). Two screws make three points of contact,
> that, like a tripod, are 
> more stable.  The two screws and rack and pinion
> should be at 120 degrees 
> apart.
> 
> But, didn't your original question ask about the
> brightness varying from 3 
> to 10 units depending on the star?  Do you mean it
> never varied before?  It 
> should have. Brightness variations are normal and
> are caused by the seeing. 
> During really bad seeing the brightness can vary 50
> percent. It's not 
> normally that bad though. I think SBIG says 10
> percent variations in 
> brightness are normal.
> 




__________________________________________________
Do You Yahoo!?
Sign up for SBC Yahoo! Dial - First Month Free
http://sbc.yahoo.com

--  APML Archives at <http://astro.umsystem.edu/apml/>  ---
             Unsubscribe at <majordomo@seds.org>