Polar alignment with a 6x30 finder

[Mr niall]

Hello there 

I have access to a heritage virtuoso base, and want to try some photography. Obviously there is no polar scope with this mount but it can be oriented equatorially so might be fun for wider field stuff. I don’t have a polar scope of any sort but I do have a little 6x30 finder with cross hair. I was thinking, that using Polaris and Kochab as a sign post I could probably get reasonably close for finding the pole. 

But... I read that celestial north is about 3/4 of a degree from Polaris, so I was wondering if anyone had any idea how far away from Polaris I should be aiming using my 6x30 ( I’m not very good at maths ?)

[Cosmic Geoff]

FOV of the finder would be about 8 degrees, making a guess at its apparent FOV, so 3/4 degree is about a tenth of the field. 

3/4 degree would fit in the field of the Heritage scope at low power, so you'd be better off using that.  But I don't know what you are going to achieve unless the mount is power-driven.

[Mr niall]

It is indeed Geoff - many thanks.

[bobro]

10 hours ago, Mr niall said:

I have access to a heritage virtuoso base, and want to try some photography. Obviously there is no polar scope with this mount but it can be oriented equatorially

Isn't this an Alt/Az mount? That usually means a wedge for equatorial conversion - does this little mount support this? In any case it should be possible to attach a camera with a lens for wide field imaging. The Alt/Az setup will limit exposure time though there is useful content in the forum about this type of imaging.

[Geoff Lister]

The Virtuoso mount has a central boss in the base, with a 3/8" UNC female thread for use with larger photographic tripods, and the manual has details of the mount's use on a wedge.

Geoff

[Mr niall]

15 hours ago, bobro said:

Isn't this an Alt/Az mount? That usually means a wedge for equatorial conversion - does this little mount support this? In any case it should be possible to attach a camera with a lens for wide field imaging. The Alt/Az setup will limit exposure time though there is useful content in the forum about this type of imaging.

Hello there - yes believe it or not it has an equatorial mode and this is now supported through the beta version of skyportal app - I was quite surprised myself when I found out so thought I’d give it a go. The biggest obstacle as I see it I should getting a half decent polar alignment. If I can get 30 secs at 100mm then I’ll be very happy indeed. Failing that, I’ll revert to alt az, but won’t cost me anything to have a play.

[bobro]

5 hours ago, Mr niall said:

Hello there - yes believe it or not it has an equatorial mode and this is now supported through the beta version of skyportal app

Interesting. Reading the manual (page 9) - this features requires a mount with what is effectively a wedge to provide the equatorial base, though how to attach the virtuoso to this isn't clear. 

[Mr niall]

It’s got a big 3/8 adaptor in the middle of the base so you just connect the wedge to that. But I’ll just try a heavy duty video tripod to start.

[happy-kat]

I get 30 seconds with a 135mm in altaz mode. You can put the mount into eq mode by a sequence of button pressing you don't need to have a wifi dongle and use the synscan pro app.

One member made a wooden wedge and just sat the mount on that.

[happy-kat]

Thought about this some more. This image was posted by member danieloliva back in 2013.

Let's assume you have virtuoso on a wedge with the camera with lens at 0 altitude (camera has either a finder scope in the flash hot shoe or a red dot finder) This would mean that you should be able to line the finder up with Polaris by altering only azumith as the mount is on the wedge. Once you have done that turn on the virtuoso into EQ mode. Job done.

In theory the mount is now polar aligned and ready for what ever you do next.

 

[Mr niall]

On 03/09/2018 at 21:10, happy-kat said:

I get 30 seconds with a 135mm in altaz mode. You can put the mount into eq mode by a sequence of button pressing you don't need to have a wifi dongle and use the synscan pro app.

One member made a wooden wedge and just sat the mount on that.

Wow I’m fairly impressed by that! What a great little mount!

[happy-kat]

Though I have a second user PDF guide where this is not in it. So try it and see.