From: Mark Gaffney <markgaffney@me.com>

Date: February 14, 2010 4:56:20 PM MST

To: "Astro_IIDC@yahoogroups.com" <Astro_IIDC@yahoogroups.com>

Subject: Re: [Astro_IIDC] Re: guiding..M 42 etc.

You know I think my collimation is out somewhat! I was getting very poor results as to focus with the Sun this morning. I still can't get the DBK to work on the PC. Frank Mraz just suggested I un-install & re-install the drivers for it. I can't work out how to uninstall drivers- I'm aware of the remove & add programs option..? Anyway I had downloaded the new v 4.1.1.1 TIS FW driver but apparently I need another thing which I'm having trouble downloading ( botchy end of month satellite broadband..) Now it's mostly overcast so I'm a bit stymied again..

Mark.

Sent from my iPod

On 15/02/2010, at 6:14 AM, milton_aupperle <milton@outcastsoft.com> wrote:

Mark;

Your not listening or not reading anyhow.

If Sirius isn't in the center field of view after a 3 star alignment, it isn't polar aligned. What your seeing is that it's off alignment and the star is drifting over time. If you let it go long enough, you'll see it "tickling" it's way out of the field of view. It should NEVER drift like that unless you have issues.

I'll make this as simple as possible. Turn on the Reticule in Astro IIDC, center a star on the Reticule crosshairs and let it sit for 5 minutes. If it drifting away from the center vertically your not polar aligned.

And spending several hundred $AUS on a Focuser will not help your problem achieving focus. It has no feedback from the camera to achieve focus, it's just a servo motor. If you can't get stars into sharp focus manually, your not going to get any better electronically.

Also, you likely will have trouble achieving proper image scale and focus when you use a focal reducer and the OAG with a Focuser.

Later..

Milton Aupperle

--- In Astro_IIDC@yahoogroups.com, Mark Gaffney <markgaffney@...> wrote:
>
> Milton,
> I`ve just done a 3 star alignment on Sirius, Canopus & Regulus & then
> done the All Star PA on Procyon. In Display Align afterwards I`m
> getting a reading of Azm: 00 degrees 00' 01" & Alt: 00 degrees 00'
> 05". I`ve only checked it tonight, with a slew back to Sirius & this
> star seems to be gradually "tickling" into the centre of the eyepiece.
> As far as aligning the finder with the camera`s centre I can probably
> do this even at night if need be, by shining a spotlight on the sign
> on our shipping container 50- 100 metres distant. Focusing accurately
> may be more problematical but I`ll see how I go..!
>
> Mark.
>
> > Mark;
> >
> > The log shows you've got really horrific polar alignment. Your
> > drifting at a rate of about 160 pixels over a 7.5 minute time span.
> > Assuming I deciphered your messages correctly, your using the 0.3
> > focal reducer, so each pixel is about 3 arc seconds and means your
> > drifting about 50 arc seconds per minute. No wonder your having
> > issues with finding objects or keeping stars in the field of view.
> >
> > You have two (possibly 3) tasks the next time your out you that need
> > to achieve before you should try imaging anything (even the sun or
> > the moon are likely impossible).
> >
> > 1) Get the Camera and Finder Scope pointing to the same object. I
> > don't care if you do this on a star, the moon or some object 100
> > meters away. Each time you rotate the camera, or add / remove any
> > optical items you need to re-do this. Once this is done right you
> > can do your alignment stars with the mount, at least you can put
> > them in the Cameras center using the Finder Scope if they are off
> > somewhat.
> >
> > 2) Learn how to focus. Your not coming close to sharp focus at all.
> > You should likely do this in the day time or at dusk on a distant
> > terrestrial object so that the motors or polar alignment are not
> > distracting factors. Make a paper target with lines or circles and
> > stick it on a building or tree. Practice getting the camera in
> > focus, because your badly out of focus on what you shot last night.
> > Part of this could be because your scope is poorly collimated, I
> > don't know.
> >
> > 3) Now that your able to find a star in the finder scope and get it
> > into the camera FOV in focus, you need to get the mount polar
> > aligned. This involves physically adjusting the azimuth and altitude
> > knobs on the mount. It has nothing to do with picking 1 or 4 or 30
> > alignment stars with the hand controller. I prefer doing drift
> > alignment but perhaps you like using the polar scope and angles. I
> > don't care how you do it, but it has to be done properly. You'll
> > need to use the scope at Prime focus, so steps 1 and 2 will be
> > critical to you achieving this, because if you can't find a star,
> > then you can't do it. And properly means that you can put a star on
> > the Reticule Cross hairs of Astro IIDC and leave it for 5 minutes
> > without significant (less than around 10 arc seconds) upwards or
> > downward drift unguided.
> >
> > Until you have these 3 basic things mastered, your wasting your time
> > with filter wheels, guiding and imaging.
> >
> > HTH..
> >
> > Milton Aupperle
> >
> > --- In Astro_IIDC@yahoogroups.com, Mark Gaffney <markgaffney@>
> > wrote:
> > >
> > > Milton,
> > > I opened the text file first but thought you`d get a basic idea
> > > from the snapshot. I WILL send it to you when I`ve finished
> > responding
> > > on group here. The idea was that I`d economise by sending the same
> > > email to you as the one to the group because our internet has
> > reached
> > > that dodgy part of the month. I know you`re the only one who usually
> > > responds & that you probably would appreciate the "nitty gritty"
> > full
> > > information professionally but I thought others might be
> > interested in
> > > what I was up to!
> > > I should enter declination of both object being guided on (object
> > > being imaged) & object being used as guide star, from what you`ve
> > told
> > > me some time ago but I couldn`t remember which entry was which
> > when it
> > > came to the crunch! I wasn`t in effect really guiding anything just
> > > getting a basic feel for the set-up & controls!
> > > I have 2 cameras at my disposal at present, the Scorpion 20SO & my
> > > DBK 21A ( The Flea 2 which I HAVE acquired star images with is on a
> > > round trip to Canada, hopefully, to have it`s glass cover looked
> > at by
> > > PGR on warranty).
> > > I only used one reducer at a time getting better results with the
> > > Mogg 0.3 than the Antares f 6.3 & one camera at a time. I didn`t use
> > > the Antares f6.3 with the Scorpion though( having removed the
> > Antares
> > > by this time & replaced it with the Scorpion equipped with the Mogg)
> > > Sorry if this wasn`t clear enough! I heeded your advice & didn`t use
> > > the CRG OAG at all..
> > > I`ve tried to explain that I can`t use the Scorpion simultaneously
> > > with another camera at present anyway..(The iBook has only the one
> > FW
> > > port & the repeater I have needs a new cable which I`ll buy this
> > week
> > > hopefully!) I could use my Mac Mini for one of the tasks but set-
> > up of
> > > two computers was too complicated for this initial trial run..
> > > Wouldn`t it be the case that with a 2 minute exposure, the
> > > stars`d be elongated anyway even polar aligned as they were? I could
> > > have another go at "All Star" polar alignment though, weather
> > > permitting.. (I notice, on my iPod, there`s supposedly a bank of
> > cloud
> > > rolling in here on the "Skippy" sky site Terry has sent me-I haven`t
> > > looked at the weather site I have yet, for a forecast.. ) PA
> > wasn`t as
> > > perfect when I did it last time as I usually get it in "Display
> > Align"
> > > afterwards but I thought the idea was to have it "out" somewhat in
> > RA
> > > anyway to give the autoguider something to sink it`s teeth into?
> > >
> > > Mark.
> > > On 14/02/2010, at 7:33 AM, Milton Aupperle wrote:
> > >
> > > > Mark;
> > > >
> > > >
> > > > On 13-Feb-10, at 8:45 AM, Mark Gaffney wrote:
> > > >
> > > >>
> > > >> I then connected the GPUSB, centred Betelgeuse using the
> > reticle in
> > > >> Astro IIDC & tried some very inexperienced guiding. Basically I
> > left
> > > >> the settings as they were already, callibrated, then began
> > tracking.
> > > >> The star drifted below the reticle gradually & I left it
> > running for
> > > >> several minutes. Here`s the log..
> > > >
> > > > You might want to try reading the manual first (see page 16 for
> > > > starters) because you did not event turn on Declination
> > Calibration
> > > > or Guiding, just RA only. The log indicates this, the Guide sheet
> > > > window SHOWS this. That's why it did not even try correct anything
> > > > on the vertical, because you didn't tell it to when you calibrated
> > > > (Dec : No Calibration).
> > > >
> > > > Secondly, that isn't the log, that's a single page screen snap
> > shot
> > > > image The log is a text file with multiple pages and one can
> > open in
> > > > Apples Text Edit and scroll through it. Do not bother sending it
> > to
> > > > the list because Yahoo will screw it up. You should do as other
> > > > people do and send LOGS as files to me directly using our
> > support e-
> > > > mail address.
> > > >
> > > > Thirdly, if it drifts out of the field of view that fast at that
> > > > short a focal length (your likely at around F 1 with the doubles
> > > > focal reducers), then your polar alignment is completely whacked.
> > > >
> > > > That would explain why your having so much trouble finding
> > objects.
> > > >
> > > >
> > > >> After that I tried slewing to M 42 again & without adjusting
> > with the
> > > >> finder took a 2 minute & a couple of 4 minute exposures (I got
> > the
> > > >> darks a bit confused with the 4 minute ones though..) Here`s the
> > > >> result with the 2 minute one. I was pleased I got some sort of
> > > >> nebulousity showing this time;
> > > >
> > > > Your stars are completely out of focus faint blobs and elongated
> > in
> > > > the vertical axis. That likely means your polar alignments is
> > > > completely off, likely on the horizontal axis, but it's hard to
> > tell.
> > > >
> > > >
> > > >
> > >
> >
> >
> >
>