What to use with Star Adventurer

[Shera]

Hi,

I'm looking for some kind of scope that will sit on my Star Adventurer and will bring out more detail than my Canon EOS 400d DSLR and lenses the biggest of which is 70-300mm. I have a Skywatcher Explorer 130 scope and EQ2 mount but it's too heavy and frustrating to use so I'm looking for something that is light and will sit on my SA and allow me to observe and take photos of planets but also galaxies and nebulae. Attached is a single exposure of the Orion Nebula taken on my DSLR using the 70-300mm lens on my SA for 80 secs. I'd like to zoom in a little more and get a bit more detail if possible. Someone has suggested the Skywatcher Eco Star 72ED DS-Pro OTA but not sure. The price is certainly good but if it won't get any more detail than my DSLR then I won't bother.  

[pipnina]

34 minutes ago, Shera said:

Hi,

I'm looking for some kind of scope that will sit on my Star Adventurer and will bring out more detail than my Canon EOS 400d DSLR and lenses the biggest of which is 70-300mm. I have a Skywatcher Explorer 130 scope and EQ2 mount but it's too heavy and frustrating to use so I'm looking for something that is light and will sit on my SA and allow me to observe and take photos of planets but also galaxies and nebulae. Attached is a single exposure of the Orion Nebula taken on my DSLR using the 70-300mm lens on my SA for 80 secs. I'd like to zoom in a little more and get a bit more detail if possible. Someone has suggested the Skywatcher Eco Star 72ED DS-Pro OTA but not sure. The price is certainly good but if it won't get any more detail than my DSLR then I won't bother.  

 

Hello.

What focal length was that photo taken at on your 70-300mm lens? I use a Nikon D3200 (same sensor format) with a Sigma 105mm f2.8 and I can manage 5 minute exposures with less star trailing. Have you made sure your polar alignment is correct? (Remember the image produced by the polar scope is inverted horizontally and vertically)

 

I wouldn't put anything with a focal length too long on the SA, I would be reluctant to put anything longer than 300mm but i don't really know the true upper limit.

This was taken with my 105mm, so I imagine your lens at 200 or 300 mm would produce very detailed results.

[SteveNickolls]

Hi,

Thanks for posting. I've had my Star Adventurer mount now since April last year and have been building up the lens FL's I use steadily and learning all the time. I notice your 80 second M42 shows some star trailing and perhaps out of focus so I would suggest nailing your technique with your present camera and lenses on the SA before jumping to even longer FL's which will likely require guiding for anything over 2-3 minutes or so of exposure. So far I've managed to build up to 3 minutes with a 300mm FL lens and with shorter FL lenses you can get 15 minutes easily and really only limited by local light pollution conditions.

Whatever telescope you move to you need to keep a close tally of equipment weight and that it stays well within the weight capability of the mount. The Skywatcher Evo Star 72ED DS-Pro OTA comes in just under 2kg and 420mm FL. A WO Zenithstar 61 is 360mm Fl and weighs 1.45kg. You will need to factor in the weight of field flatteners etc, etc into the overall weight.

Whatever you decide good luck in the future.

Best Regards,
Steve

P.S. FLO have a useful FOV calculator you could use to see what images you would get of various DSO's with any telescope and camera set up :-)

[pipnina]

6 minutes ago, SteveNickolls said:

P.S. FLO have a useful FOV calculator you could use to see what images you would get of various DSO's with any telescope and camera set up :-)

Stellarium also has a plugin (installed by default, but needs to be enabled in settings) that lets you do the same, which I prefer personally.

[Shera]

Thanks both. I can't remember what focal length I had it on to get this image but yes I noticed the trailing too and wondered if the exposure was too long? I was correctly aligned or as correctly as I could get it. The thing I haven't tried yet is stacking images, so perhaps it might be better once I have mastered the focal length? I have managed to just about capture the Flame Nebula using this lens on a single exposure, again maybe stacking would bring it out more. 

[Shera]

Just now, pipnina said:

Stellarium also has a plugin (installed by default, but needs to be enabled in settings) that lets you do the same, which I prefer personally.

Ah that sounds like what I need thanks!

[pipnina]

1 minute ago, Shera said:

Thanks both. I can't remember what focal length I had it on to get this image but yes I noticed the trailing too and wondered if the exposure was too long? I was correctly aligned or as correctly as I could get it. The thing I haven't tried yet is stacking images, so perhaps it might be better once I have mastered the focal length? I have managed to just about capture the Flame Nebula using this lens on a single exposure, again maybe stacking would bring it out more. 

You should be able to achieve multi-minute exposures even at 300mm if aligned properly without that much star trailing. I would check to make sure you have the star adventurer on the right setting, the polar alignment has been done correctly (read the manual again) and also make sure your tripod is on even and relatively firm ground.

[SteveNickolls]

+1 to all pipnina says regarding polar alignment. You could use the Polar Clock Utility in the Star Adventurer Mini app to help polar align as the view is exactly what you see through the SA's polar scope. Just take your time getting the best accuracy. I've found ending polar alignment when Polaris is just on a major division means the most accuracy you can get. As you are loosening and tightening connections (such a ball head or clutch) in the dark be careful not to induce movement in the mount by overly tightening things. There is a 'design feature' in the SA in that you can get the clutch binding if over tightened and SkyWatcher have produced a helpful video to help owners solve the issue-

 

Perhaps to build up your technique imaging on star fields, practice focus, moving the camera about and work up exposure lengths until you feel confident it is reproducible.

Good luck with your future imaging.

Cheers,
Steve

 

[JemC]

I can vouch for what @SteveNickolls says above regarding polar alignment,

I took his advice and it really did make a difference,

this is a little example in this thread that i managed using it,

 

[Shera]

That is certainly a good point regarding the clutch knob...I use the polar aligner finder thingy and I use an app to make sure Polaris is in the right place on the finder but it's possible all the knobs weren't tight enough. My other problem is last year my tripod fell over and landed on the shutter cable causing the internal SA shutter parts to come loose. Skywatcher said the problem was very difficult to fix so I assumed that was that. However I had another go fixing it the other week and with the help of surgical tape I can now take images but the shutter can be variable eg sometimes it stays open for 80 secs and then the full 1.39 secs if it's on star mode! 

[RichM63]

As you don't provide a 'signature' I have no idea what you have mounted the SA on to. Tripod??

All the above comments are valid, but if your Tripod is flapping about in the wind with the load from the SA + DSLR + Lens then you are never going to get good long exposures.

What is your Tripod rated to, and then chop at least 1/3 off that value?

My first thought on your top image was 'camera shake', but I react from a daytime photography aspect, so not exactly 80s exposures.

For better help on here, provide basic location, and include appropriate kit in a signature. That way we know instantly if we might have experience of your situation. Sig's are the first thing I check when looking at a post.

Best, Rich

[Davey-T]

Close ups of M42 etc need a long focal length which by definition means a longer heavier scope, something like a Skywatcher Evostar 90 but then the scope alone will be over weight for the Star Adventurer.

If you can get a decent image you can crop / enlarge just the nebula but it's really suited to wide field imaging, I've use up to 300mm lens on mine.

Dave