Imaging with a Star Adventurer

[Nerf_Caching]

10 hours ago, Ken Mitchell said:

My latest with the Star Adventurer.

Never imaged this area before, interesting stuff up there. I'd wish I had a bigger scope to make some close ups.

image and equipment info:

Nikon d90(mod)TS72 APO + TS72flat

settings: 432mm, f6, iso800, 360min

guiding:ZWO asi120mcsTS 50mm guidescope

Tracking: Skywatcher Star Adventurer

software:

guiding: phd2

Stacking: Deepskystacker 4.2.2

Processing: Adobe Photoshop CC, automated action set, GradientXterminator, Nik software, HLVG

 

 

Very good image! What was your sub-exposure time?

[Ken Mitchell]

12 hours ago, MarkAR said:

Lovely image, is that around the Cone Nebula?

Yes indeed, that triangle in the middle is the cone nebula  

You can also see the Hubble's Variable Nebula at the top right

 

Ken

Edited March 5, 2020 by Ken Mitchell

[Ken Mitchell]

12 hours ago, Nova2000 said:

Beautiful image! Your guiding was spot on I suppose.

Thanks!

I had a good PA, subs were very good at 240sec. Guiding was around 2", pretty good for the SA

I've been doing some 'experiments' with phd2 to refine PA on the SA. As it doesn't guide in Dec there is usually some drift and the graph won't stay in the middle.

This can be used to perfect your PA. When the red dec line falls to the bottom of the graph it means Polaris is too high on the polar scope hour circle. When it drifts to the top, Polaris is too low. From there on you can do some fine adjustments. Usually the red dec line disappears from the screen after +-10 (in my previous sessions) now it stayed in the middle for the whole session, around 3 hrs.

I also just cleaned and re greased all the gears which might also play a roll.

 

Ken

 

Edited March 5, 2020 by Ken Mitchell

[Ken Mitchell]

4 hours ago, Nerf_Caching said:

Very good image! What was your sub-exposure time?

Thanks! 240sec subs.

This is a single sub cropped. Stars are still a bit bloated because of the mod and I don't use any uv filters.

 

 

Ken

[elliot]

Rosette Nebula with the SA, SkyWatcher 72ED, and an unmodded Canon 600D.  About 35x120s @ 1600 with flats and darks. Loads of the images had to be chucked as that lot is a bit undermounted on the Star Adventurer and I think the little grub screw was too loose so there was quite a bit of backlash on the RA. I'm hoping a CLC filter (on the way from Ali Express!) and a future modding of the camera will help me out with detail.

[Nerf_Caching]

1 minute ago, elliot said:

Rosette Nebula with the SA, SkyWatcher 72ED, and an unmodded Canon 600D.  About 35x120s @ 1600 with flats and darks. Loads of the images had to be chucked as that lot is a bit undermounted on the Star Adventurer and I think the little grub screw was too loose so there was quite a bit of backlash on the RA. I'm hoping a CLC filter (on the way from Ali Express!) and a future modding of the camera will help me out with detail.

Got a similar setup as yours. Did you use guiding?

[elliot]

Just now, Nerf_Caching said:

Got a similar setup as yours. Did you use guiding?

Nope. I know I can do better...just need those elusive holes in the clouds to practice with.

[Nerf_Caching]

Just now, elliot said:

Nope. I know I can do better...just need those elusive holes in the clouds to practice with.

How do you find declination balance? Did you use the supplied dovetail or did you replace it?

[elliot]

Declination balance is a disaster with the supplied dovetail. I've added an Arca Swiss clamp and long rail to give it a bit more toward the front but it adds quite a bit of flexure.  Hopefully you can see what I've done from the image - I had the clamp and rail anyway.  If someone could tell me exactly which dovetail I could buy to improve the situation I'd be delighted.

 

 

 

[Astro_mark_c]

Took this using the Star Adventurer Pro with my Fuji XT2 and 55-200mm lens (at 200mm) ISO 800.  Stacked and edited in Pixinsight.  Image is made up of 55 x60s images with darks, bias and flats.

[daemon]

Here are M81, M82 & NGC3077 imaged from the UK South Coast on 26th March 2020 (yesterday) with the SA.

The data is pretty good - even if I only managed to grab 47 decent 60 second subs - but my processing skills let the image down.

Criticism and comment always welcome.

Details:-

• Mount:- Star Adventurer
• Scope:- SW Evostar 72ED
• Camera:- Nikon D5300 un-modded
• Guided:- PHD2 in RA only.
• Lights:- 47 x 60 seconds - ISO1600
• Darks:- 20
• Flats:- 20
• Stacked in DSS and ruined in GIMP (not GIMPs fault).

Stay safe and healthy everyone.

Daemon Steve

[Nova2000]

Hi

Does anyone use the Samyang/rokinon 135 F2 lense with the star adventurer? If so how long can you expose?

[FaDG]

On 31/03/2020 at 10:57, Nova2000 said:

Hi

Does anyone use the Samyang/rokinon 135 F2 lense with the star adventurer? If so how long can you expose?

It depends on your SA accuracy (mainly the amount of Periodic Error), how good your Polar Alignment is and your tolerance to one or two pixel trailing. 

A friend of mine uses three minutes subs with his Samyang 135 and Star Adventurer which is, I think, a very good sample. 

Stay health, Fabio

[DaveHKent]

What is the best way to find your imaging target with the SA mount? I have been out in clear skies but poor seeing recently with a DSLR and 75-300mm lens. I was looking towards Leo and fancied next time going up to 300mm and seeing what I could get of the M81 & co triplet. Finding what I have been aiming at has been hard where there are a number of fantastic images on this thread with targets nicely centered. I don't get a lot in the live view.

Just trying distant trees in daylight, I have found I can fit my scope (Nexstar 90SLT) to the other end of the dovetail bar and align the two to give me a visual view. However that only helps if I'm then only going to move them in RA and not DEC. Another option (if I can found a mount) is to piggyback the camera onto the finderscope mount on the telescope.

I have printed a red dot finderscope mount for my DSLR. Is the trick to use that to get approximately right then take shorter exposures until you have framed your shot?

[FaDG]

4 hours ago, DaveHKent said:

I was looking towards Leo and fancied next time going up to 300mm and seeing what I could get of the M81 & co triplet.

Well, finding M81 in Leo will certainly prove difficult! (😄 tongue in cheek) 

Seriously though, there are different solutions: several members suggest fitting a red dot finder to the dslr hotshoe as you're now prepared to do, and using it to point it towards your target. Obviously a basic knowledge of the sky and a sky chart is needed. Personally, I don't use an added red dot but the LEDs inside the viewfinder. It works perfectly. Another solution is to point the camera in the generic DSO direction, take a shot and Platesolve it, applying corrections as needed knowing the target coordinates. 

Edited April 25, 2020 by FaDG

[DaveHKent]

2 hours ago, FaDG said:

Well, finding M81 in Leo will certainly prove difficult! (😄 tongue in cheek) 

Seriously though, there are different solutions: several members suggest fitting a red dot finder to the dslr hotshoe as you're now prepared to do, and using it to point it towards your target. Obviously a basic knowledge of the sky and a sky chart is needed. Personally, I don't use an added red dot but the LEDs inside the viewfinder. It works perfectly. Another solution is to point the camera in the generic DSO direction, take a shot and Platesolve it, applying corrections as needed knowing the target coordinates. 

Hmm, yes M66. Why I should double check what I'm saying in posts before clicking 'reply'!

[Nerf_Caching]

8 hours ago, DaveHKent said:

What is the best way to find your imaging target with the SA mount? I have been out in clear skies but poor seeing recently with a DSLR and 75-300mm lens. I was looking towards Leo and fancied next time going up to 300mm and seeing what I could get of the M81 & co triplet. Finding what I have been aiming at has been hard where there are a number of fantastic images on this thread with targets nicely centered. I don't get a lot in the live view.

Just trying distant trees in daylight, I have found I can fit my scope (Nexstar 90SLT) to the other end of the dovetail bar and align the two to give me a visual view. However that only helps if I'm then only going to move them in RA and not DEC. Another option (if I can found a mount) is to piggyback the camera onto the finderscope mount on the telescope.

I have printed a red dot finderscope mount for my DSLR. Is the trick to use that to get approximately right then take shorter exposures until you have framed your shot?

I had the same problems as you; couldn't frame up the Leo triplet perfectly using a star adventurer and Skywatcher evostar 72ed refractor. I first aimed at the star Chertan by eyeballing it as I don't install any finderscopes onto the main scope. I also know that Chertan is on a similar declination to the Leo Triplet. Therefore, I use the RA fine tuning motors to position Chertan at the top of my dslr screen in live view. Then, I lock down the ra and dec clutches and begin tracking in sidereal mode. At the same time, I very slowly turn the declination fine tuning knob so the star Chertan appears to move to the left of the live view and off the screen. Here, I take a test shot. I keep turning the dec knob a tiny bit in the same direction until I find a bright sequence of stars at the top-right of my test shots as you can see in the photo I have attached. I use those stars to frame up the Leo Triplet by placing those stars at the top right corner of the frame. My method doesn't center the galaxies perfectly but then I can also crop the picture later anyway. The above steps are assuming you are photographing the Leo Triplet when they are rising. If you have meridian flipped and are imaging them as they are setting to the West then reverse all the directions(up becomes down and so on.). This is 48 minutes of integration with a Canon 650d stock dslr using 30-second subs at ISO 800 under Bortle 8 skies. I hope this helps and I apologize if my explanation is rather poor!

Edited April 25, 2020 by Nerf_Caching

[DaveHKent]

43 minutes ago, Nerf_Caching said:

I had the same problems as you; couldn't frame up the Leo triplet perfectly using a star adventurer and Skywatcher evostar 72ed refractor. I first aimed at the star Chertan by eyeballing it as I don't install any finderscopes onto the main scope. I also know that Chertan is on a similar declination to the Leo Triplet. Therefore, I use the RA fine tuning motors to position Chertan at the top of my dslr screen in live view. Then, I lock down the ra and dec clutches and begin tracking in sidereal mode. At the same time, I very slowly turn the declination fine tuning knob so the star Chertan appears to move to the left of the live view and off the screen. Here, I take a test shot. I keep turning the dec knob a tiny bit in the same direction until I find a bright sequence of stars at the top-right of my test shots as you can see in the photo I have attached. I use those stars to frame up the Leo Triplet by placing those stars at the top right corner of the frame. My method doesn't center the galaxies perfectly but then I can also crop the picture later anyway. The above steps are assuming you are photographing the Leo Triplet when they are rising. If you have meridian flipped and are imaging them as they are setting to the West then reverse all the directions(up becomes down and so on.). This is 48 minutes of integration with a Canon 650d stock dslr using 30-second subs at ISO 800 under Bortle 8 skies. I hope this helps and I apologize if my explanation is rather poor!

Cheers, that does help. I have a reasonable knowledge of the sky, recognizing most constellations and occasionally just use binoculars for that quick look about before going to bed, so I should be able to get by with this. I'll probably keep a tablet with stellarium to hand too.

[Nerf_Caching]

9 hours ago, DaveHKent said:

Cheers, that does help. I have a reasonable knowledge of the sky, recognizing most constellations and occasionally just use binoculars for that quick look about before going to bed, so I should be able to get by with this. I'll probably keep a tablet with stellarium to hand too.

You can also use the “same RA” or “same declination” technique for some other deep sky objects which have nearby stars on a similar RA or dec as the DSO. For example, the Rosette Nebula is on the same right ascension as the star Procyon. Bearing this in mind I can lock down the dec clutch and navigate using the RA axis only which is much easier in my opinion as you don’t have a million directions to deal with ; just a straight line. 

Edited April 26, 2020 by Nerf_Caching

[MattGP]

Ah knew there’d be an SA thread somewhere

Had mine for a couple of weeks and added a 72ed this week  No fantastic deepsky shots yet, so here’s the moon instead 😂 (well pleased with the detail)

[Alanjmolloy]

On 02/03/2020 at 10:24, Stuf1978 said:

I guide the star adventurer when I use the 72ED and it's pretty effective. I've managed subs up to 5 minutes with nicely rounded stars (haven't tried longer subs yet). As daemon indicated good polar alignment is required and I use Sharcap for that 😁

Here's my set up: 

@Stuf1978 This is a great looking rig. Mine is similar but I haven't cracked the guiding bit yet. When it comes to the polar alignment, do you just rough align manually, then use sharpcap with the ballhead but leaving the main scope roughly pointing near your target or do you do something else. I think where I've been messing up is trying to get everything pointing at the pole, using sharpcap, then moving everything which probably knocks things off. I also find that with the exact same set up as you, my camera, guide scope and everything else hits off tripods and wedges if I try moving RA much. Very restricted. Any advice on this (or PHD2) appreciated. Currently I'm assuming its the polar alignment messed up, because I get really bad streaking and a terrible graph in PHD2, although at least it calibrates :-). 

[Alanjmolloy]

On 05/03/2020 at 13:50, Ken Mitchell said:

Thanks!

I had a good PA, subs were very good at 240sec. Guiding was around 2", pretty good for the SA

I've been doing some 'experiments' with phd2 to refine PA on the SA. As it doesn't guide in Dec there is usually some drift and the graph won't stay in the middle.

This can be used to perfect your PA. When the red dec line falls to the bottom of the graph it means Polaris is too high on the polar scope hour circle. When it drifts to the top, Polaris is too low. From there on you can do some fine adjustments. Usually the red dec line disappears from the screen after +-10 (in my previous sessions) now it stayed in the middle for the whole session, around 3 hrs.

I also just cleaned and re greased all the gears which might also play a roll.

 

Ken

 

Ken,

Your work is amazing. You set a really high bar that it would be great to follow. I have the same guidescope. Two cheeky questions: do you have a foto of your rig? I'm trying to figure out how to set up my SA for guiding and have been playing with a lot of options, I have the guidescope currently on a ballhead screwed onto the L bracket. Second question: How do you polar align? I'm worried I might be knocking things off by polar aligning and then moving the scope and guidescope around.
Do keep the fotos coming, they're amazing!

Alan   

[Stuf1978]

On 06/05/2020 at 14:42, Alanjmolloy said:

@Stuf1978 This is a great looking rig. Mine is similar but I haven't cracked the guiding bit yet. When it comes to the polar alignment, do you just rough align manually, then use sharpcap with the ballhead but leaving the main scope roughly pointing near your target or do you do something else. I think where I've been messing up is trying to get everything pointing at the pole, using sharpcap, then moving everything which probably knocks things off. I also find that with the exact same set up as you, my camera, guide scope and everything else hits off tripods and wedges if I try moving RA much. Very restricted. Any advice on this (or PHD2) appreciated. Currently I'm assuming its the polar alignment messed up, because I get really bad streaking and a terrible graph in PHD2, although at least it calibrates :-). 

@Alanjmolloy Yeah I roughly align through the SA reticle then use Sharcap to nail the PA down. I never frame my targets up before polar alignment, so I have to move the scope after alignment.  I find as long as I tighten everything down properly on the SA wedge and don't tighten down the SA clutch too much it doesn't cause too much of an issue. Once I'm aligned and my target is framed up in the scope and my guide scope is pointing in the same direction it's just a case of setting the guiding away in PHD2 (make sure you have deactivated declination). I was surprised at how effective guiding is on the star adventurer as it's massively increased my exposure time and the number of sub frames I can keep. 

The only time my camera fouls on the wedge or the tripod is when I'm shooting something that's more or less overhead which is not very often. Hope that helps 😀

[Stuf1978]

97% moon from earlier in the week. Shot with a 72ED, canon 80d mounted on a star adventurer. 150 frames pre processed in PIPP, stacked with Autostakkert and processed in photoshop 😀

[GlenM]

One of the most beautiful images of the Moon that I have seen, thank you and well done.

 

Stay safe,

Glen.