SharpCap polar alignment tool

[pmrid]

Well, I'm impressed. Despite the wind tonight, I finally got a chance to give this a go. I was able, in double-quick time - 5 minutes or so - to get an "excellent" alignment and so went into a quick imaging and guiding session and was able to maintain guiding results in the half-pixel range according to Maxim. This was with an old HEQ5pro, so no great shakes as a mount. Guiding was off-axis at 450FL. That's probably the best I've ever ver had from that rig.
Very pleased. Tomorrow, I will try my other rig on a NEQ6 at 1600FL.
Peter

[GOTO]

Thanks for the info Peter, I hope to try the same tomorrow night on my EQ6Pro and RC8 too.
Cheers
Geoff

[glend]

Just remember that Sharpcap PA requires a minimum 2 degree field of view around the SCT, and some long focal length scopes maybe unsuitable to deliver that. However, it can work fine with most any sort of guide scope clamped into the mount dovetail for PA alignment. Just make sure your guidescope is pointed straight in its rings. It is a great time saver and produces fantastic accuracy.

[ChrisV]

I'm using it with an FOV 1.4x0.9deg. But its lined up pretty close to SCP before I use sharpcap. Robin has expanded the number of stars etc - its a breeze to use (be even better if my mount wasn't so bumpy when I adjust the alt/az).

[Octane]

From what I can see, it doesn't support SBIG cameras? I was wondering whether I could use it with my SBIG Remote Guide Head, or even the STL-11000M? I do have a QHY5, but, I prefer the RGH as it does dark frames automatically without me having to go out there and cover the guide scope, as in the case of the QHY5.

[pmrid]

Yeah. I wanted to make use of my STi cam but couldn't. The problem is, there's no bleedin' ASCOM driver for SBIG cams. I'm beggared if I know whey that is. SO I went back to the old QHY5 myself. It's OK for this purpose but I do prefer their QHY5-IIL for guiding.

Peter.

[Octane]

Maybe I could pop my finder on the guidescope and plonk the QHY-5 or Meade DSI-C on that? I'll have a look on the weekend. :)

H

[pmrid]

That's what I did. You don't even have to turn your mount on. The program oes a plate solve at the CWD position. You tnen rotate RA 90 degrees east or west and it does another. You say a quick prayer and it starts telling you up/down left/right and how much. It works best on a 2 degree field or more.
A guide scope is just about right.
Peter

[Octane]

I'll see if it's even physically possible for me to attach a camera to the Takahashi finder. I'm guessing probably not...

H

[Octane]

According to PemPRO, I'm within half-a-minute of the pole according to its calculations. But, I'd love to see physically, as per SharpCap's plate solved output, how far I'm actually out.

H

[pmrid]

Don't forget that this system is aligning your mount's polar axis, not your scope. So it does not matter if your scope and guidescope are not orthogonal. For SharpCap's purposes any guidescope-size scope will do the job as long as it's in reasonable agreement with your mount. I've been using an old guidescope that I've butchered a bit to accept a 1 1/4 inch EP or guide cam. I focus by screwing the objective in and out. You could even strap it by gaffer tape to your main scope to run this test if you had to.

Peter

[Octane]

It's a bit cold to go rummaging through the garage this morning. I'll have a poke around this afternoon. :)

H

[ZeroID]

Downloaded SharpCap Friday night and had a play with it, looks very good. Looks like it might become my software of choice when I go to an ASI1600mm-c. I don't need focusing control ( well, not yet anyway ) but managing the FW is going to be useful.

[LewisM]

I have SharpCap and the QHY Polemaster (just acquired) - going to do a shoot-out to see which I prefer (can't lose seeing that SharpCap is free!). I have limited horizons east and west here, so I think Polemaster will suit my situation better.

[Merlin66]

Lewis,
The SharpCap works within 5 degree of the pole - no need for East/ West horizons....

[ZeroID]

That's what got my attention. I have no E\W horizons at all. Just waiting for the clouds to move on so I can test the function. I am pretty darn close but be nice to have a confirmation test.

[Octane]

Looks like I won't be able to test this one out. My view of the SCP just clears some trees. Once the mount is rotated 90 degrees either side of the meridian, I see my back fence and trees!

H

[Merlin66]

H,
If the scope is set up to the park position, pointing to the pole with the weights downward, then rotating it on the RA axis by up to 90 degrees shouldn't take you very far from the pole......
The SharpCap software is trying to measure the rotational point of the axis vs the actual pole. The in-built plate solving routine has data for roughly 5 degrees around the pole down to 13 mag.........

[glend]

I found Sharpcap PA will work without rotating all the way to 90 degrees. My obs south wall gives good view of the SCT but once i rotate to 90 degrees the wall occludes the view. I found rotating it just about 75-80 degrees it would solve and put the pointers in place.

[Octane]

Ah-hah. OK, so I might be able to use it after all!

Now, I just need to remove my Remote Guide Head and find my QHY-5 again.

Thanks, guys.

H

[Merlin66]

Glen,
I'm surprised....
If the SCP is visible then the rotation about the RA axis shouldn't give any large movement.......

[glend]

Depends on the RA point of rotation, and height of the wall, and how far your dovetail clamp is above the centre of the RA. My CGX mount head is located below the south wall but as it is angled upward at 33.7 degrees it clears the wall nicely, straight up in the park position. However, RA centre line is below the top of the wall, thus 90 degree rotation moves the scope to where it will be blocked or partially blocked.

[Crushellon]

I absolutely love it, very easy to use and also accurate. I was going to get a polemaster, but there is no need at all now. I used to use PHD2 for polar alignment and it could be very fiddly, even with a bit of practice. But now I'm accurately aligned within 5 minutes of turning on my gear.

[ZeroID]

Clouds, clouds go away
I need to try this any way..

[rwharri12]

I'm new to AP and the southern hemisphere. Being unable to find the SCP by eye I'm using SharpCap with an Orion 50 mm Guide scope and their SSAG. I've focused the SSAG during the daytime and fine tuned the focus after dark so I know I'm in focus. I'm here just north of Adelaide and the magnetic offset is about 8 degrees so that's how I've pointed my mount and set the lat at 32. Problem is, SharpCap won't plate solve, it see lots of stars but it won't solve. Gain is set at 90. I've tried versions 3.0 and the beta 3.1, still no go, anyone have any ideas?

[rwharri12]

I can't get it to plate solve. I'm using an Orion 50mm Guide scope and the SSAG. I know I'm within 5 degrees or so of the pole, it sees lots of stars but nothing. Gain set at 90, with 8 sec exposures. I've tried changing the lat a bit and moving the mount left and right a bit, but still no plate solve. I've tries ver 3.0 and beta ver 3.1 any ideas what I'm doing wrong? Yes, I'm solving for the southern hemisphere :-)

[Lognic04]

I usually have to increase the max star size to max and min star size to 1 for it to be able to solve. I also find that declination has to be right on the index marker for it to work properly.
Hope that helps! :thumbsup:

[toc]

Just to add to this thread - it is possible to use SharpCap with the polemaster Camera. Just select it in the camera list in SharpCap :) Works a treat, and is much much easier than the clunky polemaster software.