M42 Manually guided

[Ant]

Hi Guys,

Managed to get the 80mm guide scope attached and balanced over the weekend. So I thought that I'd try it out! It was blowing a gale and I realised that guiding with the 12mm Illuminated EP on it's own isn't enough - need a barlow as well...

This is a manually guided shot of M42 - 300D - ISO 1600 - 126 seconds (single frame).

Not overly happy with the image, but it was a test and the test was a success - so I'm happy.

Ant

[CELESCOPE]

what ya mean Ant , not happy , thats a lovely image mate , only one little thing and that would need two exposures is the core , but othere wise a cracker. super job mate ,

Rog

hands on hips how come you got a clear slot , lol , hmm well i did have 1 hr on sat thinking about it done the bubble ,

[Ant]

amazing considering I live what 5 miles from you! It was clear for almost the entire night on Saturday!

Yes I realise that the core is burnt out - as I said I didn't take that to get a good image it was a test - and I think it's blumming good, proves that manual guiding (for me) is the way forward - well till I can get the skyscan

ant

[OXO]

Thats good news Ant and a good image for a single frame first go at guiding .

Even better news is whilst your guiding your observing too :lol:

James

[daz]

Ant

Are you using a lens for the camera, if so what settings please?

A cracker, by the way! If this is your test....... 8)

[OXO]

Ant,

Any chane you could explain the way you are guiding a little tutorial if you will ?

Thanks

James

[Ambermile]

Nice one Ant - makes me feel like I'm cheating with a guidescope

Arthur

[MartinB]

Ant,

Any chane you could explain the way you are guiding a little tutorial if you will ?

Thanks

James

Yes please Ant, that would be very interesting

Martin

[russ]

Great image Ant......just a shame about the star trailing. 8)

[Ant]

What blumming star trailing? - thats why the image was resized to get rid of that!!!!!

Daz, This shot was taken with the 300D at prime focus on the 8" Newt. The only setting you have to set is the exposure time and the ISO. ISO was 1600 and the exposure was 126 seconds...

Manually guiding is really easy and doesn't warrant a tutorial.

But here's a run down of the night.

Set up scope and find brightish object to align guide scope (I used Saturn), once aligned I then used my 12.5 illuminated EP in the 80mm. The most critical thing is to be 100% certain that you know which button moves the guide star which way - sounds really daft to say that, but it's amazing how quickly you forget.

Once you done all that, find the object you want to image (and this is where the large FOV of the 300D helps) in the 8", centre it and then return to the guide scope. Look through the guide scope and pick a guide star - centre the guide star in the cross hairs and star the exposure. A chair helps.

Something that also helps is to remember that when you have a guide scope that is as long as the main scope - REMOVE THE FINDER BEFORE SPINNING THE SCOPE AROUND IN THE CRADLES

If this wasn't what you were after James/Martin let me know.

Ant

[OXO]

Hi Ant,

Thanks for that mate the one thing i cant get my silly head round is say you have ya guide star in the crosshairs of your guide scope and your noticeing it's moving slightly when you re align it doesnt that show up in the exposure? silly thing to ask but i cant see why it wouldnt show up...

Thanks

Daft James

[MartinB]

Thanks for that Ant, starting to understand. Sorry to be a bit dim. Do you line up the guide scope on the same object as you are imaging or a different one. Isn't is difficult to get both centred. Sorry for the basic questions but that's where I'm at :?

Martin

[Ant]

Thats the love of the 300D - the FOV is huge so you can move things around a little in the guide scope without altering the target in the main scope too much.

As the guide scope is held in place using the same method as the majority of finders - you could in theory guide in one region of sky and image in another. But generally you would line up the guide scope with the main scope and find the nearest star (doesn't have to be that bright).

I had hoped that the FL of the guide scope and the 12mm guiding EP would have been accurate enough to counter any slight shift in the guide scope. But the size of the image that the 300D produces is so detailed that the 12mm EP on it's own isn't powerfull enough to reduce the star trails completely.

But I think that a 2x barlow would be more than enough.

Ant

Just worked it out the magnification of the guide scope with the 12mm EP is only 75x - so it's never going to be enough. But 150x should be more than enough.

[OXO]

Thanks Ant i got it now

[MartinB]

Thanks Ant. Think I've got it. I'm going to be relying on the NS8 GPS tracking in the short term, imaging with either the C8 or piggy backed ED80, so exposures will have to be quite short - Roger has gone up to 90 secs. The Fastar system will help with this when I eventually get it. Nice to know how you go about guiding though.

Martin

[Ant]

If you were to image through the ED80 and guide through the C8, you'd be able to go on till the field rotation showed - certainly a few minutes...

If it's on a wedge then it could go on to the limits of the camera.

Ant