Using the Polemaster with the Fornax Lightrack II

[1llusive]

As someone who is considering buying a Light Track 2, is the polar scope that is sold with it not accurate enough? What is the periodic error with it as compared to the PM, or give me some indication of the difference in accuracy.

The Polemaster is advertised as getting you to within 30 arcseconds of the pole. I am not sure how close people are getting with the standard scopes. I'm sure a skilled user could come fairly close to that - but you'll be putting yourself into some awkward positions in the process, especially if you're trying to keep your tripod low. And it wouldn't be as consistent as there is a little more human error involved. The tradeoff is bringing a computer into the field. That's fine if you would bring it anyway for other reasons, but many of us would love to see a PM mobile app.

 

[rareynolds]

As someone who is considering buying a Light Track 2, is the polar scope that is sold with it not accurate enough? What is the periodic error with it as compared to the PM, or give me some indication of the difference in accuracy.

how do you define accuracy? the polar scope is accurate enough to have like a 90% chance to get 5 min and more with 135mm, not 6 min with 400mm. with the PM you gain reliabillty depending on your exp.time and focal length. PE? It is neglectable, around 1 arcsec. see the fred about it

That's all I wanted to know, thanks.

If you are planning to use the PM with the LTII, do you still need to order the polar scope arm or just the adapter Fornax sells? I can't tell from the illustrations.

 

[1llusive]

As someone who is considering buying a Light Track 2, is the polar scope that is sold with it not accurate enough? What is the periodic error with it as compared to the PM, or give me some indication of the difference in accuracy.

how do you define accuracy? the polar scope is accurate enough to have like a 90% chance to get 5 min and more with 135mm, not 6 min with 400mm. with the PM you gain reliabillty depending on your exp.time and focal length. PE? It is neglectable, around 1 arcsec. see the fred about it

That's all I wanted to know, thanks.

If you are planning to use the PM with the LTII, do you still need to order the polar scope arm or just the adapter Fornax sells? I can't tell from the illustrations.

You would need this:

http://fornaxmounts.com/products/accessories/adapter-for-qhyccd-polemaster.html

Then select "no adapter is needed" when you buy the PM from a place such as High Point Scientific.

 

[Pogo65]

It is not that it is not accurate, but with any polar scope, it's accuracy highly depends on how well it is aligned with the mount's rotational axis. It usually takes a lot of tweaking to get it parallel. Once you got it well aligned accuracy should be fine, but it is just a tedious process. Polemaster does not have that problem. It is fast easy and accurate.

If money is no object, it is a no brainer if you ask me.

 

[elgol20]

• zrareynolds wrote:

As someone who is considering buying a Light Track 2, is the polar scope that is sold with it not accurate enough? What is the periodic error with it as compared to the PM, or give me some indication of the difference in accuracy.

how do you define accuracy? the polar scope is accurate enough to have like a 90% chance to get 5 min and more with 135mm, not 6 min with 400mm. with the PM you gain reliabillty depending on your exp.time and focal length. PE? It is neglectable, around 1 arcsec. see the fred about it

That's all I wanted to know, thanks.

If you are planning to use the PM with the LTII, do you still need to order the polar scope arm or just the adapter Fornax sells? I can't tell from the illustrations.

just the adpater. and a long usb cable

 

[niccoc1603]

ok thanks just received mine .

The manual is terrible.

Two newbie questions:

• Looking at the unit (like your pictures), do I have to forward the unit right or left for capturing in northern emisphere?
• the "status" led is not lit during normal operation, is it correct? What is the meaning of the status flashing light?

Thanks

 

[niccoc1603]

As someone who is considering buying a Light Track 2, is the polar scope that is sold with it not accurate enough? What is the periodic error with it as compared to the PM, or give me some indication of the difference in accuracy.

The Polemaster is advertised as getting you to within 30 arcseconds of the pole. I am not sure how close people are getting with the standard scopes. I'm sure a skilled user could come fairly close to that - but you'll be putting yourself into some awkward positions in the process, especially if you're trying to keep your tripod low. And it wouldn't be as consistent as there is a little more human error involved. The tradeoff is bringing a computer into the field. That's fine if you would bring it anyway for other reasons, but many of us would love to see a PM mobile app.

Well, I am actually using a PM Android app. It is still in a sort of beta version, but it works!

Loading…

play.google.com

 

[nyairman]

ok thanks just received mine .

The manual is terrible.

Two newbie questions:

• Looking at the unit (like your pictures), do I have to forward the unit right or left for capturing in northern emisphere?
• the "status" led is not lit during normal operation, is it correct? What is the meaning of the status flashing light?

Thanks

When you say "move the unit", are you talking about the polar scope arm on the mount? If so, you move the arm at least 30 degrees 2x as per the polemaster instructions. So looking at the polar scope arm in front of the mount, you move it clockwise 2x then move it back to the original position for the third step. In the northern hemisphere, you "start" the mount from the right position as looking at the mount from the front. It then moves in RA during the cycle.

The status light flashes fast when in the start position, and when in motion, the light goes dark. The light then begins to flash again when the mount has reached the end of its cycle.

--
Greg

 

[niccoc1603]

It will be interesting to see how you make out if you do try that method. I sent a note off to a contact I have at fornax to see what they think about loosening up the polar scope arm. I'll post any info when I recieve it!

did you get any info on how to loosen up the polarscope arm?

 

[nyairman]

It will be interesting to see how you make out if you do try that method. I sent a note off to a contact I have at fornax to see what they think about loosening up the polar scope arm. I'll post any info when I recieve it!

did you get any info on how to loosen up the polarscope arm?

Yes I did but, I suggest that you get in touch with Fornax or the vendor about that procedure.

I was uncomfortable with the procedure suggested to me by my contact and decided not to share it on this forum. If you do inquire about loosening the PS arm, I suggest that you ask for a .pdf on the procedure.

 

[niccoc1603]

"Note: if you are in the Southern Hemisphere, you should be moving the arm in the opposite direction. In that case, start at the 3:00 position"

I just used the above setup in southern hemisphere and the direction of rotation is the same as northern hemisphere

 

[1llusive]

"Note: if you are in the Southern Hemisphere, you should be moving the arm in the opposite direction. In that case, start at the 3:00 position"

I just used the above setup in southern hemisphere and the direction of rotation is the same as northern hemisphere

Thinking about this right now, I think it wouldn't matter as you're just making a circle to confirm alignment, just like someone who would do a drift alignment. I must have been overthinking this!

 

[niccoc1603]

Yes, the only difference is that you want the cable connection on the polemaster to face right so the image is not upside down

 

[1llusive]

Yes, the only difference is that you want the cable connection on the polemaster to face right so the image is not upside down

Well then that is probably why I said it that way - you want the cable facing outward, not inward, so it doesn't hit your gear.

 

[Pogo65]

Hi all,

Last night I did a little experiment. Instead of using the polar scope arm of the mount, I used some good double sided tape to stick the pole master, to the tracking arm of the mount right above the red logo. It sat nice and stable. I then put the mount in it’s most western position and iso of two movements of 30 degrees I used only 15 due to the mounts limitations. The software had no problem plotting a perfect circle and alignment worked like a dream. I left a polar finder in at the usual place and was able to calibrate it really well while using the pole master. This way you are also sure to use the actual axis of rotation. Another advantage was that I could keep it running while pointing the camera and could fine tune the alignment once it was.

cheers,

Peter

 

[starman1969]

Very good. I will have to read through this to see if it will help me with my Polemaster because I have really struggled, more so when I get to the fine tuning stage. I found that I just couldn't get the star inside the reticle, but somebody told me it was just down to the wobbly atmosphere.

Anyhow I am now thinking of exchanging my trusty Astrotrac for a Fornax 10 Lightrack II, so I may need a new holder for the Polemaster.

 

[Pogo65]

Hi Steve,

I think I have used an astrotrac adapter with my Fornax. The mounting hole is smaller but you can still use it. There are many easy ways to attach it, because it is really lightweight, even tape or Velcro can do the job. Better than overpriced adapters

 

[elgol20]

Hi Steve,

I think I have used an astrotrac adapter with my Fornax. The mounting hole is smaller but you can still use it. There are many easy ways to attach it, because it is really lightweight, even tape or Velcro can do the job. Better than overpriced adapters

 

[1llusive]

Hi all,

Last night I did a little experiment. Instead of using the polar scope arm of the mount, I used some good double sided tape to stick the pole master, to the tracking arm of the mount right above the red logo. It sat nice and stable. I then put the mount in it’s most western position and iso of two movements of 30 degrees I used only 15 due to the mounts limitations. The software had no problem plotting a perfect circle and alignment worked like a dream. I left a polar finder in at the usual place and was able to calibrate it really well while using the pole master. This way you are also sure to use the actual axis of rotation. Another advantage was that I could keep it running while pointing the camera and could fine tune the alignment once it was.

Did you do any testing to see if you really were well aligned?

 

[nyairman]

Hi all,

Last night I did a little experiment. Instead of using the polar scope arm of the mount, I used some good double sided tape to stick the pole master, to the tracking arm of the mount right above the red logo. It sat nice and stable. I then put the mount in it’s most western position and iso of two movements of 30 degrees I used only 15 due to the mounts limitations. The software had no problem plotting a perfect circle and alignment worked like a dream. I left a polar finder in at the usual place and was able to calibrate it really well while using the pole master. This way you are also sure to use the actual axis of rotation. Another advantage was that I could keep it running while pointing the camera and could fine tune the alignment once it was.

cheers,

Peter

Very interesting Peter. Please keep us informed if this method becomes your normal way of PA.

--
Greg