#30775 Sep 9, 2006
It was suggested long ago to try this so I gave it a shot. The first
thing I noticed is that I no longer hear the gearbox whirling and
whinning during slews. What did I do? I just aligned the gearbox
with the center point of the worm gear. All I did was oblong the
gearbox mounting holes alittle so I could adjust it. I was surprised
how far off the stock alignment was.
--- In Losmandy_users@yahoogr
> Thanks, I hope to succeed similarly. After my first attempt to
align the > stuff 'systematically' we got a rain here. Murphy's law?
> Clear skies will come, eventually.
> Regards, LN
> -----Original Message-----
> From: Losmandy_users@yahoogr
> Sent: Wednesday, September 06, 2006 8:10 PM
> To: Losmandy_users@yahoogr
> Subject: Re: [Losmandy_users] PEC
> Couple of comments on this issue (and from a point somewhere in the
middle > of the thread...).
> I've used my G11 for over two years now for unguided imaging (at
1000 mm > focal length and with a 1.3 arc sec/pixel Canon 20D). It has worked
well > BUT I did spend a fair amount of time in the beginning adjusting
the worm > block (though making no changes to the stock block). After getting
it > right, I haven't needed to do anything more. [Maybe I was lucky
> The second thing to mention is that if you use something like
ImagePlus to > do your stacking, you don't run into memory issues. I regularily
stack 30 > full size RAW images (converted to FITS) with my 500 Mb memory
computer. > Its no harder to stack 30 images than 5 images (though it does take
a bit > more processing time).
> ----- Original Message -----
> From: "Ladislav Nemec" nemecl@earthlink. mailto:nemecl%
40earthlink.net> > net>
> To: Losmandy_users@ mailto:Losmandy_users%
> Sent: Wednesday, September 06, 2006 10:52 AM
> Subject: RE: [Losmandy_users] PEC
> >I calmed down somewhat this morning. You are absolutely correct
about > > 'catching flies.'. You are possibly correct about virtually
perfect > > original
> > alignment of my new (I purchased it September 27, 2005 at
Woodland Camera > > in
> > LA) G11. Earlier tests indicated quite low PE specially compared
to my > > previous Celestron CG-5 that one has some 90 arcsecs of PE and NO
PEC. > >
> > I have to disagree with your comments about 'guiding out' the PE
error. I > > have been doing this for some time now and it, indeed, works very
well > > (most
> > of the time). I have to completely disagree with your statement
that G11 > > is
> > a 'wrong mount' to do unguided astrophotography. I do not think
that Scott > > would agree with that and experience of many amateurs is not
consistent > > with
> > that statement.
> > It is VERY simple. Part of the specifications (that decided my
purchase of > > the mount) is its PEC function, even with the G11 minus Gemini and
> > especially WITH Gemini L4. That functionality is completely
absent on my > > mount. It would be counter-productive to put it THIS way to Scott
> > although,
> > legally, it is undeniably the proper approach. This may be
actually a nice > > case for Judge Judy.
> > The reason why I need fairly good tracking unguided is this: I
just > > purchased advanced digital color SLR that has no ability to guide
the > > scope
> > as my other cameras (ST7, ST8) have. I have now two alternatives:
to make > > the PEC (with or without Pempro) work adequately or add a
guidescope to my > > OTA possibly exceeding the load capacity of the G11. At this
point I am > > pursuing the first alternative but if it fails, I'll have no
choice but to > > add a guidescope. I actually tried that but I really did not like
the > > situation when the mount could NOT be properly balanced along the
DEC > > axis.
> > This may not be too important since the motion in DEC is minimal
during > > the
> > guiding and limited number of results indicated that this could
be done. > >
> > I have always looked for a SIMPLER solutions if one was at least
> > theoretically possible. I'll pursue this by all available means
taking > > into
> > account the good reputation Scott Losmandy has in helping his
customers. I > > hope I have not antagonized his already but sometimes this cannot
be > > helped.
> > This should have no effect on resolution of the problem.
> > As for unguided imaging, it is possible now for shorter
exposures. > > Actually,
> > it seems to be related to the 77 s periodic error (1 or 2 minute
exposures > > are mostly adequate). It is really an issue of stacking. DSLR
color (raw) > > images are huge with a 8 MP chip. It is feasible to stack some 5 -
10 of > > them, more difficult to do it for 50 or something. That is a
software > > issue
> > I will handle only after the hardware is optimized.
> > Thanks for your friendly advice although I cannot agree with all
what you > > wrote.
> > Best regards, Ladislav
> [Non-text portions of this message have been removed]