From: Mark Gaffney <markgaffney@me.com>
Date: February 13, 2010 3:55:43 PM MST
To: Astro_IIDC@yahoogroups.com
Subject: Re: [Astro_IIDC] guiding..M 42 etc.
The weather forecast is for a clear day today..(Sunday), a possible thunderstorm on Monday (late afternoon ones here are sometimes something to be reckoned with, often causing lengthy blackouts!) then basically rainy weather for the rest of the week...So I might be right for tonight anyway..?!
Mark.
On 14/02/2010, at 9:37 AM, Mark Gaffney wrote:
Milton,
I`m sorry, I mean`t it was a 2 minute UNGUIDED exposure. What I`ve accomplished here this time, is actually getting part of the nebulous area in the FOV & CAPTURED by doing a better 3 star alignment (the one star alignment last time served it`s purpose getting M 42 into the FOV for the Flea 2 which I was using then..).If I was to use Canopus as the third star (swinging right around to the south) I might improve upon this even further..perhaps getting M 42 centred better after a basic slew doing this, or even entering a 4th star or second callibration star..
Mark.
On 14/02/2010, at 9:06 AM, Mark Gaffney 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.