Help with SPC900 lx

[zimzimma]

Hiya people, wandered whether anyone has an idea of the problem im having with an SPC900 modded webcam. Im not really sure whether i have a focus problem or not with it(im yet to try it on moon and planets). Ive tested webcam and LE works fine, however(and this maybe silly so i apologise in advance)I just cant focus on any given star. I get the donut shape and get it less and less but then when i think it should be in focus I appear to have firstly a sand-timer type shape and then a mushroom cloud that appears to get larger and larger until its completley out of focus again. I may be doing something wrong the EP's show a precise dot it just appears to be webcam. I have tried a a barlow lens and EP projection but with the same result, ive attatched a picture when I was trying this earlier tonight(this is as good as I can get it). Hope someone can help.

[chemtom24]

sounds liek collimation is out to me, cos what youve described is what you see when you slightly defocus a star at high mag when the collimation is out.

[Merlin66]

Hmmm

I think it's time to recollimate your scope.

You can watch the progress using the webcam to assist.

Start with the out of focus distorted doughnut and adjust the secondary screws to look for improvement in the image.

[zimzimma]

Thanks. Could this be out even though my eyepieces focus and my DSLR to? If this can happen is there a manual way of recollimating? thanks again.

[Merlin66]

Collimating and focus are different, but related issues.

A good collimated system gives better images at the focus.

There are many good collimating guides (search the forum on "collimating") - you'll need as a minimum a peep sight collimating cap ( just a plug that fits into the focuser with a 2mm central hole) or a cheshire collimating eyepiece.

[RogerTheDodger]

Lets take it down to basics.

You have the cam with the 1 1/4" adaptor screwed in, inserted into the focusser tube with nothing else. Focus will be achieved with the focusser wound almost all the way in for stars to be in focus - does this work for you?

In daylight I can focus the scope set up as above 50-60 yards away - this may be a useful test if you can do it as you should get a fairly good image in the capture software rather than waiting for a clear night.

[zimzimma]

Thanks all. Yes rodger, i have connected to scope via he normal route, I also tried in daytime about a week ago, seemed to be no problem but like you noticed it was at very bottom of focus arm(ive marked these for future use on the scope). Just couldnt get into focus on an evening when just looking at high mag stars, the ep show ok and so does the dslr it just seems to be the webcam. Anyhow, ive recollimated(it did seem slightly out) the scope this evening so when clear skies strike again I will see if theres any improvement. I hope so as i brought this webcam in the end for close to £100 . Thanks for the responses if theres any other suggestions please mention them as if it turns out it didnt need recollimating ill be totally stumped.

[zimzimma]

Hi people, just thought id say thankyou to all that helped. It turns out it was the fact that the scope needed collimating. I just did this manually really no laser, no special adapter and i have to say I managed to do it in 10mins. Ive attatched the pics of the same star(pole), next jupiter but the clouds rolled in. Thanks again people for your valuable advice. (dont know what that small blob is next to the star but I think the contrast/brightness may have been set to high).

[themos]

If that's Polaris, you are seeing the companion star! Polaris is a double, I've often seen it like this.

[zimzimma]

Thanks Themos, thought it may have been some sort of distortion. Thought id check on starry night pro and it doesnt seem to show on there.

[Merlin66]

All's well that ends well

Glad you got it sorted out.

[RogerTheDodger]

That's a nice clean image of Polaris Zim, good to hear you've got it sorted out

[zimzimma]

Thanks Roger, mind you while i was busy doing this I could have turned the scope slightly and viewed that other event in M101 which im sure would have been more interesting, didnt even know until someone told me at work the next day. Fingers crossed for tonight but looks like weather no good until Saturday evening. Only question is..... a pint or ......a super nova?? Thanks again bud.

[Ptarmigan]

Only question is..... a pint or ......a super nova??

Now that has got to be a no-brainer shirley ? Heheee! Anyone want to start a poll !

Glad you got it sorted, looks good.

[zimzimma]

Ok so a pint or a few it was, now i could kick myself as i noticed a break in the clouds just as astro panel suggested. Oh well bedtime and rightly so at this silly hour!