#21  
Old 22-07-2008, 09:56 PM
helioz (Erwin)
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Thanks for the update Bellbuoy,
I haven't been quite as lucky with mine as I can only get focus when I use a 2 x Barlow.
What sort of IR filter are you getting?
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  #22  
Old 23-07-2008, 12:49 AM
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Bellbuoy (Peter)
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Hi Erwin
Have you tried setting up your scope in daylight? You'll need to find something at least 100m away to aim at. If you are using a normal Newtonian scope the prime focus should be at a same distance away from the primary mirror as the mirror focal length. Measure from the primary mirror to the secondary and add the distance out to the focus point. That's about where the plane of the CCD should be (without a Barlow of course).
I've ordered the IR filter on ebay for $32 + $10 postage from New York.
I can send you the details via PM if you want.
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  #23  
Old 23-07-2008, 01:05 AM
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Your only 10 minutes away from me as well (Sydenham), so stop buying new stuff !.

Theo
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  #24  
Old 23-07-2008, 08:45 AM
helioz (Erwin)
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First images with SPC900NC

Bellbouy,
The attached images are taken with my 4.5" cheapy telescope ($64 on ebay!), a 2 x Barlow and the SPC900NC.
Being such a cheap and nasty piece of equipment, I wouldn't be surprised if the focuser is not in the right position. The image is getting sharper as I wind the focuser in but then I get to the end and the image is still not in focus. Once I use the Barlow I have no problem focusing.

I will take your advise and try it again in daylight to confirm.
Attached Thumbnails
Click for full-size image (MoonEdge1.JPG)
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Click for full-size image (MoonEdge2.JPG)
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  #25  
Old 23-07-2008, 08:22 PM
knackers
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Don't worry Theo, birthdays only come once a year!

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Originally Posted by Gama View Post
Your only 10 minutes away from me as well (Sydenham), so stop buying new stuff !.

Theo
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  #26  
Old 23-07-2008, 11:26 PM
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Bellbuoy (Peter)
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Those Moon images look pretty good to me, Erwin. The setup is quite different between imaging and viewing so it is not surprising that it is bit painful adapting a scope that wasn't really intended for this purpose.

Last edited by Bellbuoy; 23-07-2008 at 11:28 PM. Reason: Typos
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  #27  
Old 24-07-2008, 08:44 AM
helioz (Erwin)
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Daylight test

Bellbuoy,
I did the daylight test and found that I can not get focus without the Barlow. Looks like the focuser should be a bit further down towards the primary - that's why these scopes are cheap and nasty.
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  #28  
Old 25-07-2008, 05:11 PM
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Images with IR Blocking Filter

I've now captured some images of Jupiter on my SPC900NC using prime focus and EP projection with 10mm EP and with my new IR blocking filter from SmartAstronomy on ebay.
Exposure control and colour were improved, although the seeing was better than the previous night. I think the exposure was 1/100s. About 200 frames were stacked using Registax. I didn't use the wavelets thingy because I was getting an artificial line through the disc.
At least it's starting to look a bit like Jupiter and less like a light bulb.
Attached Thumbnails
Click for full-size image (Jupiter 080724 PF.jpg)
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Click for full-size image (Jupiter 080724 EP.jpg)
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Last edited by Bellbuoy; 25-07-2008 at 05:13 PM. Reason: typo
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  #29  
Old 25-07-2008, 08:47 PM
knackers
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Well, a false start for the first attempt at using the DBK21!

I start setting up the ETX scope, go to tighten the Az tension and the tension knob handle breaks so i cant lock it. Fantastic!

Ah well, off to Bintel i go.

Maybe i will just use a socket with a little handle welded to it instead. That wont break! Always knew that MIG welder would come in handy one day.
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  #30  
Old 25-07-2008, 10:45 PM
helioz (Erwin)
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Bellbuoy,
your Jupiter images a similar to mine. What's the focal length of your scope?
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  #31  
Old 25-07-2008, 11:54 PM
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Bellbuoy (Peter)
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Quote:
Originally Posted by helioz View Post
Bellbuoy,
your Jupiter images a similar to mine. What's the focal length of your scope?
Hi Erwin
My scope has a focal length of 750mm, which makes it f5. I saw a current model 150mm Skywatcher in Hardly Normal the other day with F 1000mm, which would be a bit better for planetary work at f6.7.
I find this size quite easy to handle and toteable. I'm trying out a mod on the focuser to reduce movement to the scope when adjusting.
I haven't collimated for quite a while, so I might check it this weekend.
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  #32  
Old 26-07-2008, 09:46 PM
helioz (Erwin)
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Hi Peter,
I've had First Light today for my F8 scope. We built these at our society out of 150mm pipe with a 127mm mirror with a focal length of 1016mm.
As soon as I set up the scope tonight (to image Jupiter) the clouds started rolling in .

This time around I was a little bit wiser and got the camera setup and focus worked out during daytime (see pictures below for results) which made the job a LOT easier.
I also setup one of my eyepieces parafocal with the camera by adjusting the focuser with camera, then move the eyepiece in/out without moving the focuser until I had it focused, then put 3 pieces of mounting tape on the eyepiece to hold it in that position.
I now have an eyepiece which, whne inserted to the "mounting tape stop", allows me to adjust the focuser, then swap over to the camera and have a near perfect picture .

What sort of mod are you trying on your focuser to reduce movement during adjustment? I have been thinking about how I could fit a little motor+gearbox to my focuser.


Camera daytime setup on primary focus:
The first image is an object at 1km istance, the other two are 5km away.
(Distances courtesy of google earth - great program)
Attached Thumbnails
Click for full-size image (LightPole_1km.jpg)
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Click for full-size image (HuonHill_5km.jpg)
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Click for full-size image (Lookout_5km.jpg)
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  #33  
Old 29-07-2008, 01:15 AM
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Bellbuoy (Peter)
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Slo Mo Focus On the Cheap

Hi Erwin
Congratulations on getting your new scope cranking.
Those sharp daytime pix suggest some good results to come.
Quote:
Originally Posted by helioz View Post
What sort of mod are you trying on your focuser to reduce movement during adjustment? I have been thinking about how I could fit a little motor+gearbox to my focuser.
The mod for my focuser is pretty basic, but it seems to reduce the vibration caused by focus adjustment. I had a couple of spare slow motion flex drives after they were removed to fit the motor drive. I made a shaft adapter so I could replace one of the focus knobs with a flex drive. the larger diameter knob gives a finer adjustment. The lathe work was done by a friend.
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Click for full-size image (SlowMotionFocus3.JPG)
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Click for full-size image (SlowMotionFocus2.JPG)
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Attached Files
File Type: pdf Shaft Adapter.pdf (11.1 KB, 3 views)
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  #34  
Old 29-07-2008, 08:43 AM
helioz (Erwin)
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Peter,
your focuser mod looks interesting - does it give you a significant improvement?
I was thinking along the lines of fitting a small geared motor to the focuser, but after last night's session I decided an RA motor drive is more important.

I have attached images of Jupiter taken last night. As you can see, I either get the bands on Jupiter and no moons, or the moons and Jupiter overexposed. Looking at your earlier images, taken with IR filter, the moons are still not visible. I would think that the problem is one of contrast ratio between Jupiter and its moons and to get both of them on one picture would need some photo shopping or stacking images with and without moons.

The first pic is taken in colour with a 2 x barlow, the other two with primary focus in BW.
Attached Thumbnails
Click for full-size image (Jupiter1.jpg)
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Click for full-size image (Jupiter2.jpg)
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Click for full-size image (JupiterMoons.jpg)
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Last edited by helioz; 29-07-2008 at 09:27 AM.
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  #35  
Old 31-07-2008, 08:57 PM
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Bellbuoy (Peter)
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The Jars of Jupiter

Hi Erwin
I think you're doing a bit better than I am with Jupiter. I collimated my scope last night and will try again when the clear skies return. Your mono images look quite sharp - a pretty good effort with no motor drive. You're right about the moons vs surface detail. No camera can match the design of the human eye. Maybe the right sort of filter would make a difference, but there are so many to choose from.
I'm slowly learning how to drive Registax. Dave Pretorius from Launceston has given a blow-by-blow description of how he does his Jupiter processing on his website complete with screenshots here: http://davesplanets.com/Downloads/Ju...ing%202008.pdf One thing I learned from here was that I was trying to use multipoint alignment whena single alignment box was the way to go.

I think the flexi shaft helped the focus wobbles a bit - maybe 50% improvement? I just wish Synta put a finer pitch on their rack and pinion. Focusing the webcam is much more demanding than for visual.

Last edited by Bellbuoy; 31-07-2008 at 08:59 PM. Reason: omitted URL
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