Novice after advice

[Gordo]

Hello I could do with some advice as I am rather new to astronomy and would benefit from your combined expertise!

I recently purchased a Meade etx-90 after hunting around for some time and considering what I should go for. I am happy with the scope but am having a few challenges around astrophotography that I was hoping you could advise me on. (perhaps the advice is get another scope but I hope not )

First issue is one around tracking as I have been attempting to capture images of Jupiter. Given its brightness at present its a great target for me to practice on. I am using a 2 x Barlow along with a Philips SPC900 webcam but even having done alignment (2 star not Polar btw) the image very quickly moves out of shot and I have to continually adjust, I can hear the scope tracking (its not set for terrestrial) but clearly its not quick enough.

Second question is what is the best I can expect to get in terms of quality of image? I am struggling to get good focus on the screen which perhaps is just the way it is (IE should I be doing this without the Barlow)?

I have found both wxAstro Capture, and Registrax to stack the images. The best I have managed to get so far is included here but isnt really that great compared to the amazing shots I see on the site.

Any advice on how I can improve would be greatly appreciated and thanks in advance for your help

Gordo

Jupiter_20111027_2218_46.bmp

[steelfixer]

Gordo.

First things first - welcome to the fold.

I have found that Sharpcap works rearly well with the SPC900.

I am not up with the scope you are using but if it is not keeping up in the tracking I would check the clutches as it sounds like they are slipping.

Fear not they will be someone along very shortly who will know your setup inside out and will put you right.

graham

[Gordo]

Thanks Graham I appreciate your help

It is a new scope and seems to track ok when I have the 26mm lens in, once I go to barlow and add the webcam the view is far narrower and Jupiter drifts out of shot fairly swiftly...

The scope is brand new and I can hear the gearing working as it tracks, just seems to be too slow. I will continue to scan the web and experiment, thanks again!

[steelfixer]

Hi again.

I am suprised that some else has not joined in on this one,maybe a little later on when they all get home from work.

It should not make any difference what you are using to view through it should still track properly.

When you fit it up with the webcam make sure the lead has plent of slack in it.

[Rapallokid]

Hi and welcome from me.

[divinityitself]

Hi, welcome to the site

[Si W]

First of all Welcome to SGL Gordo

When you set up the scope do you level the tripod ? what i did with mine was to set the tripod up and level it on the round metal disc with a spirit level east to west, and north to south before i attached the scope, try to get it as accurate as possible, you will need to do this for either Alt/Az or Polar set up, you should find that it will track more accurately, you can easily get 1 minute un-guided out of that type of scope without any issues, and the object will stay centre ish for five minuites or so without any problems. You ability to track an object is key to a good level mount/tripod. With regards to the quality of image, with it being a Maksutov cassegrain the image visually is very good for planetary work, i must confess i have never used a webcam but i expect with that type of scope you should get some good results, also remember a good focus is the key when imaging.

[JimStan]

I had to take my ETX-90 apart and re-adjust the motor drive gears. But if your scope is brand-new and not tracking, I would see about getting a replacement under warrantee.

AFA the image is concerned, a lot has to do with the "seeing" you are experiencing at the time. Also, that image looks fairly good to me, but the barlow may be affecting what you are capable of captureing with your camera. Trying without the barlow, or with a different one may be worthwhile. Obviously, you are going to have a much smaller image without the barlow, and that will affect the clarity of the image, too, but the barlow would be highly suspect if the image were as sharp when magnified to the same scale !

I seem to remember that I had to "train" my ETX-90's motors before using the scope under the night sky. Do you have any instructions regarding that ?

Jim S

[Astrosurf]

I had problems with tracking when I hadn't balanced my scope. Mind you, I was using a heavy DSLR for imaging. It got better when I moved the OTA down a bit. But that might not be your problem as the set-up with Barlow and Webcam is lighter. But I'm a newby still so might be well off the mark!

Alex

[JimStan]

ETX-90s have a fixed tube and mount system. They can be set up either as an alti-azimuth, or a Equatorial mount, depending on whether you set a rod to your proper latitude, or leave the base horizontal.

It is possible that the gears are working against a fair amount of imbalance, because there is no way to shift the tube to achieve a better balance with a heavy camera or eyepiece attached. But I still would like to know if there are instructions regarding "training" of the mount motors so that the tracking is proper. I do remember having to do that with my scope.

Jim S.