Newbie here - need some help with DSI 2

[Mallycat]

Hello. Yet another newbie here and I would really appreciate some help. I recently purchased my first telescope (Meade LX200R 10") but haven't really had a chance to spend any quality time using it until this last weekend. Since daylight savings has ended and the rain has stopped (here in Sydney), I have been having fun browsing the skies. I also purchased a colour DSI 2 and pulled it out the box for the second time on the weekend. I have reviewed the Matt Taylor video and read the instructions, but I am not getting the results I would have expected. I just stuck with simply JPG images auto stacked to start with and went for about 25 images (as recommended by Matt Taylor).

I have attached a couple of screen shots to this thread. The first screen shot was when I used the auto exposure button. This seemed to over expose the photo. Then I tried some manual exposures and then a short exposure, but neither delivered a result that I thought was on the right track. The image (as per the attachments) were nowhere near as clear or defined as I could see in the eyepiece. I also struggled to get the focus right, at least in part due to problems with the exposure I think.

Can anyone give me any tips on what I am doing wrong. I seemed to have more success with Jupiter, although I don't really know why that was. I also didn't get results as good as I was expecting.

Hope someone can help.

Thanks

Matt

[Ric]

Hi Matt, from your screenshots it would seem that your exposure times are still too high even at 0.7 seconds You can see that the image is improving as the exposure rate drops.

Try starting around 0.35 seconds, you may have to drop the exposures lower and tweak the focus a bit but I think you will see better results.

Cheers

[renormalised (Carl)]

Matt, do you have your zero image-shift focuser attached?? You'll be able to get very fine focus with that if you have. Do what Ric says and you should get a better image.

You said your first image wasn't useful. I'd beg to differ!!!. You may have overexposed Saturn, but you have nice shots of 4 of its moons

[Dazzler]

Hi Matt

I'm not far past a newbie with the DSI II but you may be better to try some DSO's like globular clusters whilst your getting the hang of using it.

As Ric said to me with my first efforts - keep persisting and the results will come.

Good luck!

[Mallycat]

Originally Posted by Ric

Try starting around 0.35 seconds,

OK, I will give that a go. I am just suprised that the auto exposure settings did not set this. Maybe that's because the auto exposure doesn't change exposure length.

Is this length of exposure (ie sub 1 second) typical for taking shots of Saturn?

[Mallycat]

Originally Posted by renormalised

Matt, do you have your zero image-shift focuser attached??

Yes, I certainly do. But with the over exposure, I found it hard to focus. Maybe if I get that right first, the focus will come. I also found some focusing tips by putting a cover over the scope with holes in it. I may try that if I still have problems

[renormalised (Carl)]

Originally Posted by Mallycat

OK, I will give that a go. I am just suprised that the auto exposure settings did not set this. Maybe that's because the auto exposure doesn't change exposure length.

Is this length of exposure (ie sub 1 second) typical for taking shots of Saturn?

That sort of exposure length is typical of any shot taken of the bright planets and the Moon. You have very bright targets and exposing for anything longer than 1/2 sec will way overexpose these. Typically for the Moon, it's virtually point and shoot....your exposure time can be as short as 1/500sec, depending on the phase of the Moon and the sensitivity of your camera and it's other settings, such ISO rating etc.

[Ric]

Originally Posted by Mallycat

Is this length of exposure (ie sub 1 second) typical for taking shots of Saturn?

Hi Mallycat, as Renormalised mentioned it is very typical for the DSI. I have imaged Jupiter at f/10 and my exposure time through the DSI was less than a 1/10 of a second, another image of Uranus was done at around 1/3 of a second.

The Hartmann mask is a very handy tool to have and will greatly assist your focussing and very easy to make, I made mine with an embroidery hoop and thick cardboard glued on. I have found that the three triangle pattern seems to work the best for me but there are many patterns to choose from.

Cheers

[Jen]

Mallycat

[montewilson (Monte)]

What part of Sydney are you in? We at the ASNSW may be able to help you. We have monthly meetings at our two dark sky sites (one close and one far) and a bimonthly astro imaging meeting at our Epping site.

[Mallycat]

I'm in Gladesville, so not far from Epping at least. I would be interested to learn more - thanks

[montewilson (Monte)]

We'll be having a meeting in mid June. PM me your email address and I will make sure you know when it's coming.

Regards

Monte