EQ3 Synscan Pro - first light!

[Thalestris24]

Tried out the eq3 pro earlier :). Assembling it was straightforward. I connected it up to a PC/Eqmod and put an umodded Canon 1100d with cheap 75-300mm lens on it. Set it to 200mm. I couldn't quite get M45 in but took some single subs of Aldeberan between clouds. I didn't bother with PA - just pointed in right direction and set latitude by the scale. So PA was probably a degree out!

Anyway, here a couple of subs:

90s iso 400:

 

90s crop:

 

60s iso 800:

60s crop

 

Not too bad for a quick try, I suppose!

Hopefully I'll be able to try again before too long (though forecast isn't good  ). I may have to add guiding which will complicate matters. 

Louise

[MarsG76]

...and so it begins.....

[Thalestris24]

14 minutes ago, MarsG76 said:

...and so it begins.....

Yeah, probably, he he. So far, much better than my Star Adventurer! Once you've used goto, anything else seems primitive.  Adding platesolving (which I did) is another feather in the cap of technology

Louise

[Stub Mandrel]

Cripes if that is without PA you are cooking on gas!

The new-style polarscope is incredibly easy to use.

[Thalestris24]

Just now, Stub Mandrel said:

Cripes if that is without PA you are cooking on gas!

The new-style polarscope is incredibly easy to use.

Not sure about using a polarscope here - Polaris isn't easily visible except maybe on very clear nights...

[MarsG76]

8 minutes ago, Thalestris24 said:

Yeah, probably, he he. So far, much better than my Star Adventurer! Once you've used goto, anything else seems primitive.  Adding platesolving (which I did) is another feather in the cap of technology

Louise

I agree, GOTO has spoiled us and made us lazy.... that said tho, I still revert to old school ways of object hunting.. occasionally.... but that's just another form of being lazy... generally I use the dob manually when I'm too lazy to run out the extension cord.. haha... lazy begets lazy which results in more work.... haha

Very rewarding tho...

I haven't used plate solving yet, but I'll get around to it....

 

[JemC]

That's looking good Louise 

just think, when you polar align it proper and stick guiding on it, what awaits 

[Thalestris24]

2 minutes ago, JemC said:

That's looking good Louise 

just think, when you polar align it proper and stick guiding on it, what awaits 

Thanks. I really want to avoid computer control/guiding if possible. Having said that, I haven't tried out the Synscan handset yet. Tomorrow I'll try carrying it down the stairs - hopefully without breaking anything!

Louise

[Thalestris24]

3 hours ago, JemC said:

That's looking good Louise 

just think, when you polar align it proper and stick guiding on it, what awaits 

I'm looking at the possibilities of Lin_guide running on a Raspberry Pi with the StarsPi Android interface. Interesting potential New Year project!

Louise

[wimvb]

7 hours ago, Thalestris24 said:

I'm looking at the possibilities of Lin_guide running on a Raspberry Pi with the StarsPi Android interface. Interesting potential New Year project!

Louise

Happy hunting with your new toy.

How is it "portability"-wise? That was a slight concern before.

Btw, the handset has a built in snap port, to connect a dslr to. You may have to make your own cable, though. But once you have that, you can program exposure sequences. Nice to have if you don't have/want computer control.

[Thalestris24]

2 hours ago, wimvb said:

Happy hunting with your new toy.

How is it "portability"-wise? That was a slight concern before.

Btw, the handset has a built in snap port, to connect a dslr to. You may have to make your own cable, though. But once you have that, you can program exposure sequences. Nice to have if you don't have/want computer control.

Hi

Portability is a big concern! I shall try carrying it downstairs today. I have an intervalometer anyway

Thanks

Louise

[Thalestris24]

I didn't try carrying the eq3+camera+tripod downstairs yet - it's been rather dark and misty today and the stairwells are not lit until it gets proper dark. Maybe tomorrow... However, I did try running it with a cheap, lightweight 9800mAh 12V LiPo battery. Seemed to track and slew ok :). I know my AVX will happily run from one for quite a long time though the heq5 won't even start up. I have two batteries so could parallel them up and maybe add dc-dc converters for the Pi and the dslr.

Louise

[wimvb]

SW mounts are quite sensitive to low voltage. And just because it's a smaller mount, doesn't necessarily mean the eq3 will work any better than the eq5. Only one way to find out ...

I also used to control my dslr with an intervalometer, but the button sized batteries ran out every other night. A diy cable from the synscan hc to my camera turned out much better.

[Thalestris24]

2 minutes ago, wimvb said:

SW mounts are quite sensitive to low voltage. And just because it's a smaller mount, doesn't necessarily mean the eq3 will work any better than the eq5. Only one way to find out ...

I also used to control my dslr with an intervalometer, but the button sized batteries ran out every other night. A diy cable from the synscan hc to my camera turned out much better.

I don't know about an eq5 - the battery probably wouldn't power the bigger motors. My intervalometer has an AAA battery though I've no idea how long it will last. Mind you, I don't anticipate being out more than an hour or two.

Louise

[wimvb]

Mine has a CR-something button battery, which I used in sub-zero temperatures. I've had a fair share of imaging nights ruined by battery issues. Nowadays, I run as much as possible from 240 V, or a large leisure battery.

The eq3 has smaller motors than the eq5, I believe. But it also lacks ball bearings on the ra axis. This may cause it to draw more current than a larger mount.

[Thalestris24]

1 minute ago, wimvb said:

Mine has a CR-something button battery, which I used in sub-zero temperatures. I've had a fair share of imaging nights ruined by battery issues. Nowadays, I run as much as possible from 240 V, or a large leisure battery.

The eq3 has smaller motors than the eq5, I believe. But it also lacks ball bearings on the ra axis. This may cause it to draw more current than a larger mount.

I'm sure it will be fine!

Louise

[mikey2000]

Those 60s and 90s crops are impressive - I think you must have nailed the polar alignment, even if just by accident.  Good work!

[Thalestris24]

2 minutes ago, mikey2000 said:

Those 60s and 90s crops are impressive - I think you must have nailed the polar alignment, even if just by accident.  Good work!

The 60s sub is ok at 100%, the 90s one clearly shows eggy stars. At only 200mm the problem is more likely to be caused by periodic error, I think. When the clouds go away (next year??) I'll do some more and will set up a guide scope when I can.

Thanks for the positive encouragement!

Louise

[mikey2000]

I suppose it depends which way the eggs are stretching - it could be RA periodic error or elongation from DEC drift if the PA is a bit off....

 

For what it's worth, I guide my EQ3Pro and get long term accuracy within 1 to 1.5 arcseconds (with occasional dec glitches that send it way off).     I've overloaded my mount with 5+ kg of scope, camera, guider etc.  I have a feeling it would be better if I reduced the payload.... The recommended max load is 5.5Kg for visual use and (conventionally) half of that for photography.      Under that load, my Eq3Pro has a +/-19" periodic error (over 11 minutes approx worm period) and a more annoying short-period error of about 2" over about 19 seconds.    I can guide these out but I've moved to a bigger mount to cope with my heavy scope and camera.

 

I find the EQ3 quite portable.  If I carry it with the counterweights pointing down, I can sort of scoop it up, no problem.  I'd probably remove any camera gear/scope if I was going up and down stairs as one trip/stumble could suddenly get quite expensive or even physically painful.... 

 

May I just add....  I'm surprised Polaris is hard to see where you are.  Is it light pollution or maybe a building in the way?  If you can see polaris, even faintly, it should be relatively easy to see in the polarscope.   The catch is that the polarscope is not illuminated, so you can't see the reticule in the dark.  I have a red LED 'fingerlight' taped near the entrance hole for the polar scope.   It's  a tricky balance between providing too much illumination (and washing out polaris) or too little such that you can't see the reticule.  At the same time, you need to be able to twiddle the alt and az adjustment bolts.  (It's not a process I enjoy!)   If you can check/calibrate the polarscope alignment during the day, you will be able to get a pretty decent polar alignment.  I use an iphone app (PS Align) that shows where polaris should go -  I found that much easier than using the synscan handset to work out where to place polaris.

 

I think you've already found the EQ3 DSO Challenge thread - lots of very very helpful people there.

 

Enjoy!

[Thalestris24]

Hi

Yeah hard to tell exactly what was causing the elongation with just a couple of quick subs. One day there will be a clear or partly clear evening. One day...

FLO actually quote 5kg for imaging and 7kg for visual for the eq3 pro. I've put it on the heq5 tripod which should help. I'm sure it will cope with my dslr+lens! As long as I can safely carry it down the stairs... I doubt I'll be putting an actual scope on it though may try my 80mm APO at some point  if things go well.

Yeah, it's the lp/humidity/skyglow which limits what I can see and what I can image. I swear it's getting worse year on year

If I can add a guide scope I may be able to drift align with the Linux version of PHD2 but I think I'd need to connect up a screen/keyboard to do that - starting to defeat the object! But maybe I could drift align manually. It doesn't have to be brilliant at 200mm.

Louise

 

[wimvb]

8 hours ago, Thalestris24 said:

Yeah hard to tell exactly what was causing the elongation with just a couple of quick subs.

If you align the RA axis with the side of the sensor, it will be easier to determine the direction and possible cause of elongation. Just do a 30 second exposure and press and hold the ra slew button on the hc after 5 seconds have elapsed. The trail will show you how to rotate the camera for alignment.

8 hours ago, Thalestris24 said:

If I can add a guide scope I may be able to drift align with the Linux version of PHD2 but I think I'd need to connect up a screen/keyboard to do that - starting to defeat the object! But maybe I could drift align manually. It doesn't have to be brilliant at 200mm

I think that with the focal lenghts you'll be using, you can use the synscan polar alignment routine. It's pretty fast. With a zoom lens, I would do star alignment at the longest setting, and if possible, use live view. Maybe put a small centre mark on the live view screen? (On a piece of clear plastic taped to the back of your camera, perhaps.)

With short fl, aligmment isn't critical. Especially if you also use guiding.

With my 135 mm lens, and no live view or computer hookup, I've done alignment through the viewfinder of my dslr. Just drew imaginary diagonals and tried to put the alignment stars in the middle. Then 10 s exposures to confirm. Got 7 min unguided exposures without too much trouble.

With 200 mm fl, your resolution (arcsecs/pixel) will be numerically the same as your pixelsize in micrometer, usually about 5. This means that any error smaller than this won't show up in your images.

Best is not to overanalyse the situation, but just fix it when you find out what doesn't work.

[Thalestris24]

Thanks, I'm sure I'll manage - I've been imaging for a few years now

Louise

[Astroscot2]

Hello Louise,

Wondering  if you had benn able to do any futher testing of the mount?

 

Mark

[Thalestris24]

Hi Mark

Not really, I'm afraid. I'm trying to get a Raspberry Pi 3 - based guding system up and running. Not much success so far!  I did get up at 5 am to take a snap of Jupiter/Mars but 8s exposures probably don't count... However, the mount seems ok (for the money) with what I've done with it so far.

Louise