Semi portable astrophotography setup?

[AlphaOrionis]

Hey guys,
I'm interested in investing in a decent scope sometime this summer, so I figured I would take the time to shop around. I'm looking for a 6-8inch telescope on a goto/tracking mount that I could use for astrophotography. I currently have a dslr, so I'm hoping that getting this setup won't be too complicated/expensive.

Ive been looking at the NexStar 6SE and 8SE, and both seem to fit the bill. However, I have a couple of questions.

As I understand it, in order to do proper long exposures of deep sky object, you need an EQ mount that will prevent the object from rotating in the field of view. The NexStar doesnt come with one of the mounts. Ive seen stacking software that would track planets in the field of view even as it moved across the eyepiece, is there by any chance a software that could auto correct the rotation? Related to this question, if anyone has a few images of what I can expect to get out of a Nexstar for astrophography that would be great!

My second question is, is there any way to improve the zoom? I saw a video on youtube of someone with the dslr attached to the NexStar and the moon still fit within the frame. What if I wanted to get closer? For nebula's and galaxies it'll be fine, but if I wanna get some nice shots of saturn/jupiter/mars/moon I would like to get closer. How can this be done?

Thanks ahead of time, and if there are any better suggestions for a telescope, please let me know! My biggest issue really is having to lug around a huge EQ mount with counter weights... I'd hope there might be another solution. I'm willing to pay up to 1500 for a decent setup.

Cheers!

[graemlourens]

Hi

When i started, i bought a nexstar evolution 6", and fast found out that visual is not my thing, its astrophotography.

The Nexstar series are with Alt/Az and will limit your exposure to between 20 - 30 seconds depending on where you point. Longer and the stars at the edge of the field will 'rotate'.

Stacking will autorotate the images correctly, but you're still limited to around 30 seconds.

With the focal lengths of those telescopes (around F10) you'll have to image very very long.

In the end i decided to get 2 setups, one for visual (the evolution/nexstar) and one realy setup for astrophotography.

There is a focal reducer for the SCT's of nexstar/Evolution, that will help with the focal length, but you've still got fieldrotation problem.

Orion and Andromda and the moon obviously will be possible, but thats pretty much it (i tried)

To get closer to the moon you could do afocal photography (putting dslr infront of an eyepiece with special adapters) but this can get pretty wobbly in some cases (especially haning on 1.25 inches)

Regards, Graem

If you really want to do Astrophotography i don't think you'll get around an EQ mount, and a 'faster' scope.

But if i were you i'd first find out what kind of astronomer you are, visual or Astrophotography?

[graemlourens]

sry, something was fishy with my browser, it shifted around sentences hope you can follow the logic

Btw about lugging around stuff:

If you organize yourself well its not that huge of a thing. I got 5 nicely sized plastic boxes, that fit everything in. Everytime i go out, i just have to pack all 5 boxes and off i go

Astophotography takes time, it takes me around 1h to setup every time (and i think thats pretty short )

[AlphaOrionis]

sry, something was fishy with my browser, it shifted around sentences hope you can follow the logic

Btw about lugging around stuff:

If you organize yourself well its not that huge of a thing. I got 5 nicely sized plastic boxes, that fit everything in. Everytime i go out, i just have to pack all 5 boxes and off i go

Astophotography takes time, it takes me around 1h to setup every time (and i think thats pretty short )

Thanks for the replies graemlourens!

I have been stargazing for a bit over a year now with some astro binoculars (10x50 and 15x63) along with a cheap starblast 4.5'' reflector. I previously didn't have much money to spend on this hobby, but a lot has changed for me this year and I can finally indulge. 

Although the telescope is a really cheap beginner scope, I coupled it with some pretty expensive 1.25'' parts (TeleVue Barlow, Explore Scientific Eyepieces etc). I found the views to be actually quite good all things considered, but it always bugged me that I couldn't take pictures of what I could see, for both myself, and for friends and family.

The way I see it, if I got myself a setup that could do astrophotography, I'd get the best of both worlds. I could view without taking pictures, and if I felt like taking pictures I could. It would be tough to pick only photography or only viewing.

Do you think you could show me what kind of pictures you took with your NexStar? I'd be really interested in seeing what kind of quality I could expect, or if I should really go all out with the EQ mount.

Thanks!

[graemlourens]

With a focal reducer the 6" and 8" works for imaging, i just had tough times with things like focus, and you'll have dew issues on SCT very fast

If you are in a lightpolluted are those 2inches more or less will not make a huge difference in my opinion. So i wouldn't got a spend on those 2" more if you're seeing is bad.

The Goto of the nexstar is pretty cool i think and works out of the box.

I don't have anything much else than the moon with the nexstar. Shot Orion once and that worked out pretty ok (just my focus was bust)

You can expect smth pretty much like this if you know/learn how to post-process including stacking & so on: http://www.astrobin.com/full/161265/B/

That was done on the Alt/Az mount, but was a small refractor. I guess you can get pretty much the same with the nexstar.

So i guess you could start off with that scope & play around with imaging for a while until you maybe want to go real deep into AP

I guess other people can also still give you advice, this was just my experience when starting stargazing.

[AlphaOrionis]

With a focal reducer the 6" and 8" works for imaging, i just had tough times with things like focus, and you'll have dew issues on SCT very fast

If you are in a lightpolluted are those 2inches more or less will not make a huge difference in my opinion. So i wouldn't got a spend on those 2" more if you're seeing is bad.

The Goto of the nexstar is pretty cool i think and works out of the box.

I don't have anything much else than the moon with the nexstar. Shot Orion once and that worked out pretty ok (just my focus was bust)

You can expect smth pretty much like this if you know/learn how to post-process including stacking & so on: http://www.astrobin.com/full/161265/B/

That was done on the Alt/Az mount, but was a small refractor. I guess you can get pretty much the same with the nexstar.

So i guess you could start off with that scope & play around with imaging for a while until you maybe want to go real deep into AP

I guess other people can also still give you advice, this was just my experience when starting stargazing.

That image is really more than enough quality for me! That's a beautiful shot.

I'm in an artistic field so I have had my fair share of playing around with processing images, although I know it will be different for AP, I am more than willing to get good at it. Im wondering if there is any advantage in being able to take a 60 second exposure picture, vs 2x 30 seconds stacked. If there is not that much of a difference I think that going for Alt/Az with some dedicated post-processing might be best for me.

[graemlourens]

you're asking the right questions

30 x 30 seconds or 15 x 60 seconds

The longer the exposure one will nearly always be better (google signal to noise ratio SNR) so you can not make it up just with more 30sec frames, you've got your limit. And only west & east pointing targets you will be able to image for 30 secs, north and south it will be slighly less (maybe 20) before field rotation becomes an issue.

The list of targets you can get with 30sec exposures is short, but there are a few on them that will certainly keep you busy for a while.

Something else that i've learnt: one seems to buy & sell eqipment rater frequently in this hobby

I always tought i have to buy new, and thats really not necessary.

Maybe you can get a second hand one? If you'd be closer i'd sell you mine as I want to sell it in any case, but i guess transport costs from poland to canada would kill us both

Regards, Graem

[AlphaOrionis]

you're asking the right questions

30 x 30 seconds or 15 x 60 seconds

The longer the exposure one will nearly always be better (google signal to noise ratio SNR) so you can not make it up just with more 30sec frames, you've got your limit. And only west & east pointing targets you will be able to image for 30 secs, north and south it will be slighly less (maybe 20) before field rotation becomes an issue.

The list of targets you can get with 30sec exposures is short, but there are a few on them that will certainly keep you busy for a while.

Something else that i've learnt: one seems to buy & sell eqipment rater frequently in this hobby

I always tought i have to buy new, and thats really not necessary.

Maybe you can get a second hand one? If you'd be closer i'd sell you mine as I want to sell it in any case, but i guess transport costs from poland to canada would kill us both

Regards, Graem

haha yea there would probably not be any advantage for either of us to do that thanks for all the information though, I'm a long way from buying anything just yet, I want to learn more and keep shopping around, and all the info you gave me was very helpful!

Cheers!

[graemlourens]

Very good not to buy too fast.

It took me a while to understand: the stars are not going anywhere soon

[happy-kat]

You might enjoy reading this thread.

http://stargazerslounge.com/topic/228101-the-no-eq-dso-challenge/

There is adding a wedge to a mount that you might also want to read up on.

I guess allot depends on how serious you want the AP side to be.

[AlphaOrionis]

You might enjoy reading this thread.

http://stargazerslounge.com/topic/228101-the-no-eq-dso-challenge/

There is adding a wedge to a mount that you might also want to read up on.

I guess allot depends on how serious you want the AP side to be.

wow that is a great thread! I wish there were more like it, I cant believe these were taken without an EQ mount... I live in light polluted skies, and getting an EQ mount might be good for one I leave town, but if these guys were able to get pictures like that on a non EQ mount, I think I'm sold... I wont be taking AP as seriously as most, if I can get shots that resmple the ones in that thread with such modest setups, I will be more than happy.

[happy-kat]

Only you know where your real pull might be visual or imaging to know where you might compromise on what you choose.

Were there any images on that thread taken with either of the telescopes you are considering.

[dph1nm]

The disadvantage to shorter exposures (and hence more subs to get a given total exposure) is that you get more doses of read noise from the camera. This makes observing with short subs less efficient - how much less efficient very much depends on camera and sky conditions. It can range from hardly any effect to completely dominating the noise in your stack! However, it does not stop you imaging! You can still do NGC objects with an alt-az - you just need to do even more subs. The real thing which would worry me is the long focal length of the 6SE and 8SE and the accuracy of the tracking on these mounts. I think you might struggle even to get 30sec subs. You can get round this by binning up to larger pixels, but you might have to do this before you stack, which is a bit of a pain.

NigelM

[happy-kat]

Would adding a wedge help with the tracking accuracy?

[AlphaOrionis]

The disadvantage to shorter exposures (and hence more subs to get a given total exposure) is that you get more doses of read noise from the camera. This makes observing with short subs less efficient - how much less efficient very much depends on camera and sky conditions. It can range from hardly any effect to completely dominating the noise in your stack! However, it does not stop you imaging! You can still do NGC objects with an alt-az - you just need to do even more subs. The real thing which would worry me is the long focal length of the 6SE and 8SE and the accuracy of the tracking on these mounts. I think you might struggle even to get 30sec subs. You can get round this by binning up to larger pixels, but you might have to do this before you stack, which is a bit of a pain.

NigelM

Hey dph1nm,

Im slowly leaning towards the Nexstar Evolution (which should have a better mount), but im wondering if 6'' would be enough. From the thread that was linked it seems that the Nexstar 102SLT gave the most bang for buck (I can get that scope here for ~550$). I like the Evolution because it's a hassleless all in one package with an on board battery, and reasonably easy to move around.

What I'm wondering is how the Nexstar 102SLT was able to get such amazing light gathering, I thought that it was designed for planet viewing not deep sky objects... As it stands now I'm wondering if just getting a 102SLT might be simpler and more affordable, or if I should get a 6'' Evolution, or an 8'' Evolution.