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D.A.R.V (Drift Alignment by Robert Vice)

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#1 Charlie Hein

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Posted 06 January 2013 - 05:15 PM

D.A.R.V (Drift Alignment by Robert Vice)

By Robert Vice

#2 Scott in NC

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Posted 06 January 2013 - 06:58 PM

Very nice! Thanks for sharing that information, Robert. :applause:

#3 highfnum

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Posted 06 January 2013 - 07:07 PM

nice i going to try it

#4 Takashi

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Posted 07 January 2013 - 07:44 AM

Really cool! Will try this as soon as possible.

#5 Littlegreenman

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Posted 07 January 2013 - 02:56 PM

I don't do astrophotography, so I don't need this level of alignment. But, I do appreciate clever thinking!

LGM

#6 Raginar

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Posted 07 January 2013 - 11:41 PM

Robert,

You mention that the corrections would be different for a GEM and I guess I don't understand why that is so. Can you clarify?

BTW this is probably the best example I've found. The pictures really clarified what I'm looking for from my image.

Chris

#7 Traveler

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Posted 08 January 2013 - 05:23 AM

Robert,

You mention that the corrections would be different for a GEM and I guess I don't understand why that is so. Can you clarify?

Chris


+1

#8 Doc Bob

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Posted 08 January 2013 - 06:37 PM

Thanks Robert,
I keep reading posts/articles referencing "drift alignment". I understand what it is but not having a GEM go-to mount, I havn't really paid any attention to technique. This does help lots! I eventually will go the rout of a GEM mount for my refractors.

Good viewing!
Bob

#9 Maverick199

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Posted 09 January 2013 - 01:34 AM

That is an excellent idea, thanks. Hope someone or I try this out with a GEM and report results. Only wish I had dark skies.

#10 Lightning

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Posted 10 January 2013 - 08:32 AM

Cannot for the life of me thinking why GEMs should be adjusted any differently to a fork. Perhaps he means the actual adjustment knobs will be in a different place? No idea.

#11 Raginar

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Posted 10 January 2013 - 08:22 PM

Lightning,

I can't think of why it would be different either; minus the actual motions of the GEM. But you should figure that out when your "V" is bigger or smaller based on how you move it.

This is the best example I've seen though. I'm really glad he put it together since i was hoping to learn this technique this year.

#12 hcsceo

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Posted 11 January 2013 - 01:16 AM

Man I wish I had read this before I started my imaging run tonight. I'm definitely going to give it a go. I've been using PHD but this looks much easier.

#13 Jerry Hubbell

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Posted 11 January 2013 - 10:09 PM

This method has been around for a long time. I first discovered it several years ago as described by Dr James Hall. For a thorough explanation see:

http://www.minorplan...aralignment.htm

I also describe this method in my book and provide a complete procedure also in chapter 12.

http://www.amazon.co...actical-Astr...
  • timshea likes this

#14 Raginar

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Posted 12 January 2013 - 12:45 AM

Hey Jerry,

Your explanation is good too! Thank you for posting the follow-up information.

#15 Jerry Hubbell

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Posted 12 January 2013 - 10:50 PM

Thanks Chris,

I meant to post the link to the original source... Jim Hall
http://www.physiolog.../hall/polar.htm

#16 astrnmr

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Posted 26 January 2013 - 11:29 PM

Hey all, thanks for the comments. Sorry it has taken so long to respond. GEM mounts function slightly different in respects to the OTA positions as well as the need to "flip" the OTA direction once it is moves from East to West. When this occurs, your image is now reversed. Therefore, depending on whether or not you "flip" the OTA over, your adjustments may or may not change. A fork mounted scope never reverses the image while moving from E to W and eliminates the possibility of having to reverse your adjustments.

#17 Lightning

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Posted 31 January 2013 - 02:36 AM

Thanks Jerry, that makes sense!

#18 corduroy

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Posted 26 April 2014 - 10:59 AM

Hey all, do you think this method will work on a curved bolt barn door tracker like this? I believe the barn door tracker is rotating along the RA axis. I have my barn door mounted to a pan/tilt head on a a tripod so I can adjust the azimuth and altitude albeit not precisely.

Posted Image

The DARV instructions states to move the mount to the west and then to the east. Is moving W or E the same as rotating about the RA axis CW or CCW?

#19 Ernst Marais

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Posted 10 May 2019 - 02:56 AM

I am from the Southern hemisphere, so I take it I should point North in setting up?



#20 F.Meiresonne

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Posted 29 December 2019 - 05:42 AM

I don't quite understand it completely.

 

For the altitude one use thesame movement of the telescope , so moving it in RA again to the west? as for the azimuth?

 

And why a 6 mag star? Rather have a bright one to point the telescope and camera to

 

Then the issue remains on how to move the mount , confuses me al the time,the second exposure will make it better or worse but in the end this is a trial and error method , and those Always cost time...and you have to remember your previous steps. Really i have trouble with this...



#21 timshea

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Posted 17 August 2020 - 08:38 PM

Did this last night. Worked like a charm. Simple after a few tries. Thanks so much for posting - super helpful when Polaris isn’t in view. 

 

I did 180 second trails. 90 sec out & back. Maybe 3-4 passes on each axis, rechecking each once. You can get quite accurate alignment this way. 

 

I used the compass and (mostly) inclinometer apps on my mobile phone. First to set true north and level everything. Then to quantify my adjustments in response to the star trails.


Edited by timshea, 17 August 2020 - 08:50 PM.


#22 timshea

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Posted 17 August 2020 - 08:48 PM

I don't quite understand it completely.

 

For the altitude one use thesame movement of the telescope , so moving it in RA again to the west? as for the azimuth?

 

And why a 6 mag star? Rather have a bright one to point the telescope and camera to

 

Then the issue remains on how to move the mount , confuses me al the time,the second exposure will make it better or worse but in the end this is a trial and error method , and those Always cost time...and you have to remember your previous steps. Really i have trouble with this...

Once you try it, it becomes easier. Basically:

 

- Align mount as best you can manually. 

- Point the scope south (at 0 DEC). Move it east and west. Adjust mount until “V”s become flat lines.

- Point the scope east (at 0 DEC). Move it north and south. Adjust mount until “V”s become flat lines.

 

Star magnitude didn’t matter at all for me. All 500 stars in view made the same “V” shape.




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