Multiple night imaging help

[drumsolo]

Hi sorry if this has been asked before but I can't find all the answers I need.

My current imaging setup is SW200pds on HEQ5 pro autoguding and imaging with a canon DSLR. I want to try imaging over multiple nights to get more data and hopefully better images. I have never tried this so my question is if I leave my camera attached to the scope in the same orientation how do I re align the scope the next night if I am not using an eye piece to find the alignment stars? Am i simply using the camera live view instead of the eyepiece? Could I in theory leave my scope powered up all night continually tracking so it doesnt need re aligning? If I parked the scope can I resume from Park position after turning the power off and it will still be aligned? Sorry if these are dumb questions, I'm just trying to find the simplest way of doing this!

Thanks in advance

Stuart

[D4N]

Using plate solving is the best way as the software can point the scope in exactly the same place.  Astro tortilla is free and can do this.

[Droogie 2001]

I faced the same question about a year ago and without a Dome or pier its an inevitable question.

As D4N says Plate solving is the way to go. It takes a bit of effort but once you have it working you won't look back.
 

 

[Toxophilus]

Hi,

Ideally you do need to leave the camera on the scope to eliminate rotation alignment issues (although pixinsight and nebulosity will handle this when registering/aligning). I recently did an image over 4 nights, breaking everything down each night and setting back up again. The only thing was that I left the camera on the scope. I did not use plate solving to get alignment but did it manually. What I did was to slew to the object and get it in a rough position to align. I use Nebulosiy for my capture so what I did was load up a reference image from my first run and then using the mouse right click on the image on 3 bright reference stars. This leaves a marker on the image that you can then use to do a quick 5-10 sec exposure and  then fine tune the alignment stars to your markers and start your imaging proper. Using this technique, this was the end result of 4 nights of imaging: http://www.astrobin.com/271584. The image was processed in Pixinsight so the technique definitely works.

[ollypenrice]

My first suggestion would be to align the camera with RA and Dec. This is easy: just align it by eye as you put it onto the scope then take some 5 second subs while slewing slowly. The star trails generatated like this will be at the present camera angle, which you adjust and repeat the test. Being aligned on RA and Dec makes any return to the same target so much easier. When you've done this you can use Tippex, if you like, over the camera and focuser to help you realign perfectly if you have to remove the camera.

Ideally you leave the camera in the scope and use it to find your alignment stars and centre them. My capture software has a reticle on the screen so this is actually more accurate than using a crosshair EP, not that this matters much.

Olly

[Steve 1962]

I agree with everything the other guys have said.

I'd like to add another vote for platesolving from me. The ease of astroimaging was transformed when I discovered AstroTortilla. I found (and still find) it remarkable that it could put me back in exactly the same place night after night.

I now use Platesolve2 which I find faster and easier to use, but I still have AT installed...just in case.

Another remarkable thing about those two pieces of software is that they're free - so have a play!!

Standby to be amazed.

Steve

[StargeezerTim]

If, like me, you don't use a computer, then you can resume the next night after parking the night before without needing further alignment. I just check the polar alignment is still good then 'resume from parking'

 You save your position on synscan and just goto that position the next night. Do check focus is still good and you may need to adjust the camera orientation slightly. 

The biggest problem is getting more than one clear night in the month!

Hope this helps.

[drumsolo]

Thank you Stargeeezer Tim for your advice. Whilst I appreciate the other comments these have just confused me even more. How do you save your position on synscan?

yes I agree consecutive clear nights is asking a bit much!!

[PeterCPC]

Also, if you are using Backyard EOS you can load a previous capture and align that with current captures.

Peter

[StargeezerTim]

1 hour ago, drumsolo said:

Thank you Stargeeezer Tim for your advice. Whilst I appreciate the other comments these have just confused me even more. How do you save your position on synscan?

yes I agree consecutive clear nights is asking a bit much!!

You save your position as a 'user defined object' giving it a number. I think you can save up to 20. Next time, you goto user defined object 1, or whatever number you gave it. Provide you put the correct date and time in, it will take you right there. It took me a couple of times to feel confident. Read the synscan instructions and you will soon be be able to do it! 

[drumsolo]

Ok so do you save your position and then Park the scope? Then power on the next night and start from Park and go to user defined object?

 

thanks again

stuart

[Steve 1962]

Have a look at this...

https://www.youtube.com/watch?v=3KA16FrQ65g

 

[StargeezerTim]

46 minutes ago, drumsolo said:

Ok so do you save your position and then Park the scope? Then power on the next night and start from Park and go to user defined object?

 

thanks again

stuart

Exactly! Its worth just checking your polar alignment first before you turn on. You can also go to bright star first to check your focus if there are no bright stars in your intended field of view. Cheers, Tim.

[wimvb]

In addition to Tim's advice, I would also take Olly's: align your camera sensor with the RA axis. While stacking software can handle image rotation, if you lose corners due to camera rotation, you will have to crop your images much more. Once you've done it a couple of times, it becomes a natural part of setting up your gear. And if you can't use your camera for goto alignment, use a barlow together with short focal length reticule eyepiece. This will greatly improve goto accuracy.

Good luck

[Adam J]

On 16/12/2016 at 13:37, drumsolo said:

Hi sorry if this has been asked before but I can't find all the answers I need.

My current imaging setup is SW200pds on HEQ5 pro autoguding and imaging with a canon DSLR. I want to try imaging over multiple nights to get more data and hopefully better images. I have never tried this so my question is if I leave my camera attached to the scope in the same orientation how do I re align the scope the next night if I am not using an eye piece to find the alignment stars? Am i simply using the camera live view instead of the eyepiece? Could I in theory leave my scope powered up all night continually tracking so it doesnt need re aligning? If I parked the scope can I resume from Park position after turning the power off and it will still be aligned? Sorry if these are dumb questions, I'm just trying to find the simplest way of doing this!

Thanks in advance

Stuart

Yes that is exactly what I do I align using back yard EOS and live view. But you dont have to leave the camera attached. You can rotate the image as required just so long as its not too far out. I align the bottom edge of the camera with the bottom edge of my focuser.

As you are using a Newtonian the most important thing to do is to never remove the scope from its rings as if the scope rotates in its rings your diffraction spikes will not line up and no amount of processing / plate solving will help you.