Does goto track stars?

[poider]

G'day just wondering about tracking and goto mounts, do I assume that if a mount / tripod has Goto capabilities then it also has tracking capabilities, does any scope that comes with a goto hand controller automatically track objects, or do they have to be bought separately.
I know we can buy a mount that goes between the camera/ scope and tripod is that the tracking mount, I understand that Goto is a hand controller that you can press buttons and the scope will go to any object in it's database, but once there will it track the object? and will that tracking be suitable for long exposure photography?
Peter

[spiezzy]

hi there Peter
yes a goto scope most will track the object the answer to your last question is it depends on how long you want your exposures if you are only doing 20 or 30 seconds you can get away with no guiding but if you are going longer a guide scope will be needed most of your bigger will with have guiding capabilities .
it really depends on your budget and what you are planning to do
cheers Pete

[Merlin66]

Peter,
All the GOTO mounts I know of are capable of tracking.
The accuracy can vary from mount to mount, but if properly polar aligned can usually allow long camera + lens exposures.
When you start to consider imaging with telescopes + cameras then you need to consider additional guiding - where a separate scope and camera identifies any variation in the tracking and issues corrections to the mount to improve the accuracy.

[poider]

thank you spiezzy
I have a cheap 150mm newtonian reflector but it is not stable enough for astrophotography, so i am thinking of buying a mount for my sigma 150mm to 500 mm lense and nikon D7000 and just using the scope for observing
Peter

[silv]

How heavy is the 150 Newt?

I'm asking because it's quite possible that you could get a tracking mount that can accommocate either the Newt with your camera or the camera with your lens for astrophotography - and not pay (much) more than if you get one of them tiny tracking photo heads.
And still be reasonably portable - incase that's a requirement for you.

If the Newt ways like 4kg or so you could get a motorized EQ5. They often also come up 2nd hand.
If it's heavier - well, then the mount would be in a different price class.

[poider]

My Scope with camera come to 4.2 kgs the scope is 3.5 kgs and the camera 870 grams

[poider]

My camera and lens come to 2.7kgs

[poider]

Thank you Merlin, I am a little curious about these guiding scopes, if you are in the middle of a long exposure and the scope needs to have a correction, wont that then ruin the photo with it's movement/ correction?

Peter

[silv]

Cool!
A mount that is officially labelled with a load capacity of - ideally - 8kg, but possibly also a little less than 8, can carry your setup for astrophotography.

If the tube is nicely short it can be balanced very easily. If it's a longish tube then not so easily. Good balance is of course necessary for good tracking results.

But yeah, an EQ5, motorized: go for it :) With Goto: even better!!

I wouldn't bother with guiding, though.
It complicates things enormously, adding a computer and software and more cables into the equation - and thus also makes your setup less portable.

And: if you take 20 exposures of 30 seconds each, unguided, you collect the same-ish amount of light that you get in a single guided exposure of 10 minutes.

If you calculate with 30 seconds exposures you can even consider a motorized Alt-Az-mount. The Goto-Versions are also cheaper than the EQ Gotos and they're easier to setup, too.

The game of astrophotography is changing.
Where it was the mount that was the most important and expensive thing in imaging,
nowadays, this is more and more becoming the imaging camera.

You start off with your DSLR, a 150mm scope and a so-so mount - and eventually upgrade the camera to a CMOS.
While still working with your so-so mount and 150mm scope. I'm sure of that.

[poider]

Thank you Annette, I will start to lok around and when I have some spare cash I will look into it.
Peter

[poider]

My Tube is 750mm and it is well balanced for observation, It is a national geographic scope, my wife (also named Annette) bought it for me for father's day, I have a t ring and 2X barlow / adapter I have put the camera on and it is very hard to balance but it isn't too bad, I have done some Moon shots, cannot get any planets clearly in photos. but then I never expected to be able to get any photos.
Peter

[silv]

awesome! 750mm is on the shorter side of Newts when it comes to the effect on balancing. With an EQ5, you'd be just fine.

I personally have no experience with Alt-Az mounts at all and I don't know how good they work with 150/750 newts. I assume it would work, too, but I just don't know.


So you think you'd rather get a tracking mount for the scope setup than for the camera only?


[A sturdier mount would also make your visual sessions more delightful :) ]

[silv]

yup. we are everywhere. beware! :D

[poider]

I am thinking that for astrophotography just the camera the lens and the mount, if I can get one. I would try the scope and camera with a mount and see how it goes

[sil]

Peter, Yes! a camera, lens and goto mount will let you get a ton of great targets photographed. The Sigma 150-500mm lens is an awesome lens but at 500mm the weight of the glass will wind it back in to 150mm once you point it upwards. I made a plastic collar to go on mine and hold it out at 500mm.

You need to get away from this mindset of pressing a button and taking a "photo". Astrophotography is about gathering a LOT of photons and combining them to reveal fainter structures that you cant see through a viewfinder and reduce noise.

My photo of the Pinwheel galaxy (http://www.astrobin.com/163046/0/) was taken with a Nikon D800e and Sigma 150-500mm just mounted on a GOTO mount. No telescopes involved. I took around 500 photos to combine and process, the galaxy wasn't visible in the JPegs from the camera (I take JPEG+RAW always) as it was still too faint but the GOTO mount had put it dead center for me. OK its an underwhelming photo but its what you can expect with processing.