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Old 25-12-2014, 07:27 PM
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FrankyT (Frank)
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Join Date: Dec 2014
Location: Sippy Downs
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My Skywatcher NEQ6 and 200mm Reflector

Hi there 3 months ago I purchased a Skywatcher Neq6 mount and a Skywatcher 200mm reflector to use for astrophotography. I have learnt a lot over this period as I have had a lot of trouble and if you are like me with issues please read on. There are many issues I have encountered. I have not even ventured into stacking and photo-shopping etc. Life is not always fair the next guy wont have trouble but you may.

Any one who can add or even disagree your comments welcomed.

The Neq6 mount appears to have a wide quality tolerance when it comes to unguided photography (no piggy back scope and camera following a star to keep your mount guided correctly). Some guy on the net was complaining he had star trails after 8 minutes unguided - I wanted to hit him. I was getting trails after 30 seconds and this is where people's opinions differ - What is an acceptable length of time for an unguided Neq6 to not produce start trails? I decided if I can get a 2 minute unguided shot without star trails I would be happy with that. In short I have produced a 5 minute unguided shot. However at the same time elsewhere in the sky - star trails. You see the closer to the equator you are the worst a misalignment will show up. I am getting ahead of myself but if you are beyond that do not read on.

Set up and balance and don't forget to align the finder scope at some stage - I do it when I am aligning as the gear is not easy to move without power - its clumsy. First all is your mount pointed south - not magnetic south? For me it is 11 degrees to the left of magnetic south. The Neq 6 has enough adjustment for a few degrees either side but not 11 degrees. Next do not trust the bubble level on the mount. Take off the mount and use a spirit level on the tripod and adjust the legs so its balanced in all directions. Get this right some say it doesn't matter but others also say cone error doesn't matter but ill mention that later if you are still here.

Make sure your power supply is good enough so the led on the mount doesn't flash. Push the cigarette lighter plug in tight or better still change the plug type.

Follow the instructions on the keypad. Make sure you know your exact co-ordinates - degrees and minutes - use your phone gps or similar. Adjust the time to the second and adjust the altitude of the mount to your location.

You know you are on a winner when the first star for an alignment is at least in the view of the finder scope.

I start with a two star alignment and then a polar alignment. If successful then do a three star followed by a another polar alignment. I then use a a x5 barlow with the illuminated reticule eyepiece to do further polar alignments. Correct polar alignment is critical if you are not auto guiding. Now even after all that I am at the stage where I have polar alignment but still can have star trails at some parts of the sky but have improved from 3 months ago. I will still hone in my alignment skills. Yes I can get a auto guide system and will in time.

I mentioned cone error before which is where your scope may not be exactly perpendicular to the mount and again who you listen to can or doesn't cause star trails. As I was getting desperate in eliminating possible causes to star trails I looked into it and hopefully you don't have to. Yes the 3 star alignment supposedly adjusts for cone error but arguably only to a certain amount. I had significant cone error and had adjust one end of my dovetail a couple of mm as it was way out. In any case it certainly improved the goto system.

A friend has suggested I need to use a laptop for more precise polar alignment - eventually yes.

On another matter - Collimation. Did you know your collimation is only as good as your laser collimator? Yes the suckers can misaligned themselves. I now use a modified 35mm film canister which does a better job. See the manual of the Skywatcher.

All the best for Xmas.

Last edited by FrankyT; 25-12-2014 at 08:11 PM.
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Old 26-12-2014, 09:03 AM
Hoges (John)
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I've got the HEQ5 mount fairly level and reasonably well aligned on the south pole - no noticeable drift in Dec after 10 minutes. But, the mount does noticeably wander back and forth in RA. With a 50mm lens, I might get an 8 - 10 minutes exposure and nice round stars. Through the 600mm scope, even 2 minute exposures show some elongation. (Does a bit better towards the pole). If you're photographing through the reflector (1000mm ??) then I wouldn't be surprised if you have less than perfect stars even with relatively short exposures.

Check you have no movement in declination - I found the drift alignment explanation on the Ozscopes web page the easiest to follow and understand. If it's just movement in RA, then it's likely periodic error.

Also, set your camera for a 2 second delay after you press the shutter - it will give some time for the vibrations of shutter/mirror release to die down too. (I use a cable release too).

I think I'd be inclined to drift align the mount first before doing the star alignment but I don't have the goto capability so I could be wrong there... but I have spent a few hours drift aligning over a few nights to get the best results I can and I don't think I'm getting much better results than yours even though my scope is permanently mounted.
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collimation, cone error, drift, neq6, star trails

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