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Auto guiding at last :-)

Started by Whitters, Aug 06, 2007, 22:14:18

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Whitters

Got everything up and running at last, five minute subs, will try for ten next time. IR block filter ED80 and the MX916.

DDP applied to enhance structure in M27.


The area around gamma Cygni. The focus is a little soft


No calibration performed on images so they look a little shabby, I'll have a go at calibrating them later.

Rocket Pooch

Well done Paul and welcome to the club (autoguiding that is).

The images are ok, but as you said the focusing needs a little work, did you bin the shots at all and was it with the G11?

Chris

Whitters

Binned at 2x scope was on the Losmandy, using a dedicated guide cam.

JohnP

Hi Paul,

Congrats on sorting your guiding....

M27 looks good - focus is definitely a 'bit soft' & looks like you have pushed it too hard in processing - all the stars saturated...

What are you using for a guide cam..? Have you got a new laptop now then...?

John

Mike

Paul,

Well done. I agree with the comments - the focus is out and you have gone a bit OTT with the processing, but those are minor issues in getting your guiding working at this stage. The stars are pretty round for 5 mins. Once you fine tuned the technique I am sure you'll be producing great results with the kit you have.

The next time you have a go can we see a raw frame as well as a set of processed stacks please.
We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology. Carl Sagan

Rocket Pooch

Hi Paul,

I looked at the image and compaired it to a couple of other I've seen, I'm guessing but I think you used the 600mm lens for this which with a binned MX916 would give approx 7.83 arcs/pix, this will give you an undersamples image and will definately add to the look of it not being in focus, the little stars are spread across a large pixels.

The ideal if approx 2 arcs/pix unless you have a sadistic streak in you, at 1x1 you will get 3.91 arc sec per pixel, the optimum focal length / resolution for the HX916 is a 1200mm scope, like the Vixen or 8"SCT at F6.3.  The image of the crescent nebula I did the other day was 2.3 arcs/pix and you can still see little square stars in it, the high res M27 i did was 1.22 arcs/pix.

So with hindsight the image is possibly not out of focus just undersampled, also I guess you would be within the +- 4 arc/sec per pixel to get bang on round (or little square stars).

Having said all that, considering the issues you have been having with the kit its a great result.

Chris


P.S. See http://www.stanmooreastro.com/pixel_size.htm


Fay

Paul, I never realised that you had not done guided imaging. Just goes to show than no matter how long in the hobby you have been, there is always something else to learn.
Did you do it easily or has it taken a while to get the hang of?

Fay
It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!

Whitters

Hi Folks,
Thanks for the comments and help. I know I over processed M27 but that was to get the most out of the structure of the nebula, but it has resulted in dark rings around the stars.
Chris, that is an interesting point on undersampling when I ws focussing the HWFM was around 1.20 so I was dissapointed with the result but your explaination would fit the bill.
The Scope used was the ED80 with the MX916 at 2x bin, I have been having venison blind problems when running at 1x but that may be to do with tracking problems.
Fay, I have been trying to get auto guiding to work on and off for years with the Starlight STAR 2000, and only managed i once. I have now got one of the Starlight Express autoguider heads, and the USB2 kit. Hi John it's still the same old 2000 vintage laptop with a USB2 card.
Here are a couple of raws from each stack, as from the camera, no processing.



Rocket Pooch

Paul,

the blinds might be the USB cable, call me at home and I'll explain there's some stuff on the SE forum about that :-)

Chris

Fay

Chris, I had that problem, didn't I, & we set the setting to HI Res Prog.

Paul, have you looked on the SX Yahoo group for help with STAR 2000. I have got the facility but never tried to use it as it does take some of the quality from the image.


Fay
It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!

Mike

Blind venison can really be a nuisance. Still.. I guess they are nice and easy to catch if you sneak up on them.
We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology. Carl Sagan

Fay

There is a lot of puessing the meanings of posts,  on this site, especially with Chris's posts. We probably raed then eniterky disserfent to what Chris attended.



Fay
It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!

Mike

What the.......... ?

Fay I think that being completely smashed out of your trolley at 0953 in the morning is disgusting. I am ashamed of you.
We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology. Carl Sagan

Rocket Pooch

I lick to keep poople guessing as to wat I'm tryping.

The blinds could be either Interlace Lines or the USB Cable being of low quality, if they are uniform the MX use interline chips which is why they can do the star 2000 guiding, but on shorter exposures they look all liney....

Ian

it's taken me this long to work out what the blinds were.

And there was me thinking I had no eye'd deer...