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Astrotrac first light

frugal

By frugal
in Getting Started With Imaging

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frugal

frugal

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My beloved wife bought me an Astrotrac for Christmas. Now that the relatives have all gone home I had my first play with it. The weather here has been foul for the last week, and tonight was due to be almost uniformly cloudy. However I did manage to get half an hour outside where I could see the stars. I did a few trial runs indoors to see how the Astrotrac fitted onto the tripod and how the ball joint fitted onto the Astrotrac and how to power the whole thing up. 

It all went together smoothly. I had a bit of trouble getting the 20 year old tripod to stay where I put it, and I had to learn how far out I needed to aim, so that when I tightened it all up it ended up where it needed to be. then I set it going and took a test shot. First shot, star trails. So I checked the Polaris alignment and it was a bit out, so I tried to realign and took another shot. Long star trails... I tried this about 3 times, each time the alignment looked a little out, but not hugely. Ok, so the alignment needs to be really dead on then...

Hang on...

You unfold the arm one way for south of the equator and the other for north of the equator. I wonder.... Yup, I had unfolded the tracking arm the wrong way. As you can guess the air turned a bit blue. Ok, reverse the arm back to the starting position, and fold it back up and down the other way. Then take another test shot... Wow!. Okay, that works. 

I did not bother to take the laptop out because there was no way I was going to be out for more than half an hour. So I had not way of taking a shot of more than 30 seconds, and I had no way of focussing other than taking a shot and fiddling with the focus by hand, then taking another shot. Even so I managed to get something half decent. So this is a stack of 6 30 second subs at 300mm iso 800 and 6 darks. I cropped the image to about half size to concentrate on the nebula. Stacking was done in Deep Sky Stacker with some fiddling with in Photoshop afterwards. 

By no means an Olly standard photo, there are still some minor star trails due to bad alignment, and the focussing is off, but not back for half an hour with a new toy and no laptop to help with the focusing.

post-32477-0-81552900-1388181867_thumb.p

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frugal

frugal

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Glad you are enjoying it :).

Any chance of some pictures of the Astrotrac?

Unfortunately it is put away for the night, I will take a few photos the next time I get it out. I have ordered a new tripod and geared head that will hopefully turn up on Monday, so I will certainly take a photo then.

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StuartJPP

StuartJPP

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Nice one and a great start.

Don't feel bad about unfolding the arm out for the incorrect hemisphere...I did it fairly recently as well. I was standing behind the mount and unfolded it, took me a couple of test shots to realise my mistake, as I knew I had alignment spot on after the 5th attempt :rolleyes:

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frugal

frugal

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Glad you are enjoying it :).

Any chance of some pictures of the Astrotrac?

Here you go. The new tripod and head turned up today (no thanks to CityLink).

I might have sort of spent some of the money I was saving up for a mount on the new tripod and geared head. My wife's 20 year old tripod is good, but it is hard to polar align with it.

Sent from my GT-N7000 using Tapatalk

post-32477-138850060788_thumb.jpg

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Adamar98

Adamar98

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Nice first light! One thing I will advise on is collimating your polar scope. Mine was way off when I first took it out of the box. During daylight, pop your polar scope into the holder and centre it on a chimney. Turn the polar scope in the holder and see if the chimney stays central. If not then you need to adjust one of the small Allen screws on the side of the polar scope. Keep adjusting till it stays central. Have fun. Looking forward to seeing more images from you.

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frugal

frugal

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Nice first light! One thing I will advise on is collimating your polar scope. Mine was way off when I first took it out of the box. During daylight, pop your polar scope into the holder and centre it on a chimney. Turn the polar scope in the holder and see if the chimney stays central. If not then you need to adjust one of the small Allen screws on the side of the polar scope. Keep adjusting till it stays central. Have fun. Looking forward to seeing more images from you.

Well, 

With the new tripod and geared head to help with the stability and alignment, I went out to play for a couple of hours this evening before going out to New Years. I managed a 10 minute shot @ 135mm with no visible star trails. I would say that the polar alignment is good enough ;)

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ian_bird

ian_bird

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I have the same rig - apart from I went for another geared head in place of the ball and socket.

Plus I glued a finder foot on to the camera (actually the 200mm ring mount) so I could add a red dot finder.

Lovely setup. And nowt wrong with the Manfrotto tripod either. I hang a weight under it to (clamped so it can't swing) to damp vibrations.

Enjoy. And I look forward to enjoying your images.

Cheers

Ian

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frugal

frugal

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I have the same rig - apart from I went for another geared head in place of the ball and socket.

Plus I glued a finder foot on to the camera (actually the 200mm ring mount) so I could add a red dot finder.

Lovely setup. And nowt wrong with the Manfrotto tripod either. I hang a weight under it to (clamped so it can't swing) to damp vibrations.

The Ball head came with the AstroTrac as part of my Christmas present from my wife ;) It certainly does fine for the moment.

I am planning to take the camera rucksack out and hang it from the hook as an added weight, although in the shelter of the house it does not currently need it. Certainly if I ever take it out to the top of the bury, I will be hanging the rucksack as a weight.

I am wondering how I can add a foot for the Telrad to the top of the camera, so that I can aim it more accurately. At the moment I am pointing it at roughly the right area of sky and taking a 10 second shot at the largest field of view to highlight the major stars, then centring the target and increasing the zoom until I get the shot I want. Having access to a Telrad or similar will make it easier.

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ian_bird

ian_bird

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Hmmmm. The idea is to reduce vibration - not add it! :tongue:

Hanging a rucksack from the mount on top of a bury (which I assume is a hill) sounds like a recipe for disaster to me. Swinging in the wind?

The weight is to damp out vibration - which you will get even in the shelter of your house. Mainly from you!

I posted elsewhere about DSUSB and long extension cables - Ah - here it is:

http://stargazerslounge.com/topic/203296-advice-for-best-make-of-canon-shutter-remote/

Will try to set my rig up and post a piccy showing the finder. Works a treat.

Hope this helps.

Cheers

Ian

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ian_bird

ian_bird

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I tried the hotshoe route - but found there was too much play in it. That's why I superglued a WO Red Dot Finder shoe to the 200mm tube ring.

Maybe a hotshoe with a locking ring would do the trick? My Canon flash guns have them - but I wont be butchering those! ;-)

Cheers

Ian

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Digz

Digz

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Seriously thinking of getting an Astrotrac , do you guys use the AA battery pack ? how long does it last ?

Dave

I havent used the batteries on an extensive session but they should last all night.

I have a decent set of Ni-Mh batteries (2900mAh) and an intelligent battery charger which allows me to charge 4 batteries independently as well as test etc. Im hoping once I have collimated the polarscope, and we get some clear skies, I can get back out.

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frugal

frugal

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Seriously thinking of getting an Astrotrac , do you guys use the AA battery pack ? how long does it last ?

Dave

I got about 6 hours from the first set of batteries, but it was about 5C which is never a good temperature for batteries ;)

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