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Star tracking


Nelson

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hell all, it is a fairly clear night so I thought I would try some astrophotography using just my eq mount and my Canon 600d camera. After setting everything up I got focus and took some 4minute pics but when I looked at them I noticed that my mount had not tracked the target. I set the tracking rate at 2. What should it be? Please help I've been trying for hours now and guess what, it's clouded over. Any tips?

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I'm not an imager but will start with the simple stuff.

Have you polar aligned?

Have you 2 / 3 star aligned?

Have you aligned to the correct stars?

That's all I can think of now without further info.

To be honest, I have never heard of anyone setting a tracking rate, are you talking about sidereal?

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Hi there thanks for your reply, yes did Polar alignment Etc. and I got pics of my target but on each pic, although no star trails, each one had moved but still in focus. I set the rate to sidereal should it be something else?

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Sidereal is the correct option for planets and DSO's.


 


As i`m not an imager or own a EQ mount, I`m going to bow out now, as if you have polar aligned (and it is spot on) 2/3 star aligned and have the correct time/ date and tracking options I am at a loss.


 


Sorry I cant help further, I`m sure somebody will be along shortly who knows the answer, good luck.


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4 minute subs unguided you probably will see some movement. But the movement should show as a trail, and you say you don't see trails. Do you mean the stars look like eggs or even shaped like a V?


 


Can you post a pic?

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Hi I have not yet processed my pics and have only looked at them on my camera. Sadly I cannot post any pics as I am using an iPad and have been told that Apple will not allow this. The pics look very sharp but what I'm struggling with is why each frame has kept target in view but slightly in a different position

I wonder if I should have different settings and not sidereal. I used a one star alignment as. I have been told it's the way to go for astrophotography. What should my tracking rate be? And will they stack OK?

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I used a one star alignment as.I have been told it's the way to go for astrophotography. What should my tracking rate be?

 

Your tracking rate should be sidereal but what I am confused over, who has told you to do a 1 star align, I have never, ever, heard of 1 star align ?

 

With one star align, how will the mount know where everything is, as you need 3 points to plot a position do you not?

 

So 2 x stars and your location of the mount?

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Stacking should take any movement out. I use  DSS.


 


If you are only imaging one object then a 1 star alignment on the nearest alignment star to it in your mount library works fine.


 


2 or 3 star alignment is really for when you are moving around the whole sky to look at/image multiple objects using Goto.


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1, 2 or 3 star alignment is purely for calibrating the goto, this has no effect on the alignment.


 


One does not need goto to take images.


 


Whats your mount Melvin? Im trying to understand the tracking rate multiples you mention. If its a standard SW driven EQ mount with handbox you just need to leave it running as this is sidereal, 2x will speed it up and you will get trails.

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Sounds like your polar alignment is off ever so slightly and what you see is Field rotation in each sub.


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What Noel ^^^^^^^^ said!!!!  :P


It shouldn't be an issue, when I go away from home to my darksite I quite often see the same as I haven't spent time getting perfect alignment.


Stacking software takes care of it and a bit of cropping post stacking.


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