From: "milton_aupperle" <milton@outcastsoft.com>

Date: February 14, 2010 12:14:29 PM MST

To: Astro_IIDC@yahoogroups.com

Subject: Re: guiding..M 42 etc.

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.