M57

A nice clear sky at 11:30 pm so I set up to see what I could catch. Got M57 in my sights and set up the DSI, centred the object and got her focused. Set the colour, increased the exposure then pressed start.Two images later, the quality dropped to 1% for the next few images and a glance up to the sky told me why. Yes, the clouds were back with a vengence.
So, it really needed a lot more than two images but here it is:
LX90 8". DSI. 2 exposures at 20 seconds combined in autostar.
www.irishastronomy.org/user_resources/fi...1121563290-M57-1.jpg
Bill H.

Bill, for two images, that's pretty good!

As a suggestion, click the 'save proc' button in the right corner and choose 'Jpeg' as the file tyoe and 'Save all Uncombined images' as the save options. Next, click OK. In the main screen, choose your min quality as a low number - try 10%, 5% or even 1% and choose an evaluation count of 1.

What'll happen is that you will still get your composite image (ie stacked image) but you'll additionally get all the individual frames that make up that composite. Bear with me.... Your composite is just as you would normally get but Autostar will NOT delete each of the frames that go to make that composite.

What you can do then is examine each individual frame and pick your best ones - then stack them in Registax or Autostar. Effectively, you are are doing your own quality control - its a bit more time consuming but you'll find you lose less images to the dreaded 1% indicator....

If you are imaging, and a cloud passes, the DSI will still take the frame - but you can chuck it out later. Of course, if a cloud the size of Meath passes by, you're buggered...

Keep it up Bill - you're really doing well. Think back 3 months, could you have captured this image? Also, I bet you can set up in half the time now! And then just think what you can do three months ahead of now

Cheers

Dave McD

Well the clouds have now cleared, it's 4:00 am but unfortunately the sky is too light to see anything, let alone image.
Dave, I was so close to doing what you suggested, but changed my mind, I wish I hadn't. Still, I'm quite satisfied with the image considering it's only two. just wait until I get another go at it and see what it's like then. I reckon it would have been an acceptable shot had I managed about 50.
Maybe tonight.
Bill H.

Bill,
Thats a good first go of it, do you think you could have gone for longer exposures to bring out the image more, or was the tracking not up to it ?

Looks like the DSI is a nice piece of equipment,

I was comparing the image to the one I got of M57 last year with the 300D and the red light response is not as different as I thought it would be.
The inside of the oval on yours looks a little yellower. It striking how narrow the FOV is, you just about cought a glimpse of the central star.

Keep up the good work bill.

Thanks Dave,
I increased the exposure in increments of 5 secs, and at 25 secs you could see the tracking going off, so had to cut back to 20. I would like to think that a wee bit more detail would have come through if had managed my minimum of 50 images, although I would have prefered the images at about 30 secs, at that exposure you could see the detail popping into view on the laptop, but tracking was horrendous at that speed. The first live picture was a thrill, but the next one was just a smudge right across the screen.
It looks promising for tonight so will see what I can do with it, but so far the weather here is always glorious all day, then when a bit of darkness comes, so do the clouds, but fingers crossed.
Can you post your image Dave, I would be interested in seeing the comparison.
Cheers.
Bill.

BIll - here's one I took back in June (11th). Its 5 images of 10 secs each. C8 wilth 6.3 reducer (though I've cropped the image a little).

Maybe the DSI needs more exposure time for colour?

The central star is just discernable in your image. Stick with the 20 seconds if that's what the mount will do - if you get over 20 or so images, you'll see the detail coming out probably more than if you go for a longer exposure. But then again, with your darker skies maybe I get light-pollution washout at the longer expsoure durations...

Keep at it!

Dave L - the 300D image would be an intersting comparison.

Cheers
Dave McD