EQ6 / Atlas GOTO's Cone Error 3 STar Alignment?
Posted 04 September 2008 - 06:49 PM
Recently did a Hypertune on my EQ6. All is super re: guiding tracking
but I keep failing the 3 star alignment consitenly and somtimes the
controller my say "alignment may not be close enough"I also swithced
to having the aligment stars come up by magnitutde instead of
alphebetically, which was a great help...I think.
I was doing 3 minute guided subs last night with errors < .5. Imaging
scope 80Ed Gudied scope 66mm WO apo with DSI and PHD
I did check with the mount pointed to Polaris...I moved the RA side
to side and polaris was shifting in my ED80 scope considerably looking
a 26mm eyepiece...so there is an issue somewhere mechaniacally. Not real
Is there a problem with letting the SYNSCAN pick the stars?
Thanks for any suggestions help
Posted 04 September 2008 - 11:39 PM
How do you get the alignment stars to show by magnitude instead of alphabetically? I've got an older firmware version, so I may or may not have that option. But I'd be curious to see it.
Posted 05 September 2008 - 12:22 AM
I have version 3 of the controller..under alignment stars in the setup menu you can sort alphabetically or by intensity.
I found the front ring on the imaging scope to be very loose to teh dovetail lifting up and off a little and now things are good again.
Another suggestions i got on the yahoo site was to use the one star aligment near the object to image and that works well ...have not tried it
Posted 05 September 2008 - 01:25 AM
Posted 05 September 2008 - 08:27 AM
Posted 05 September 2008 - 10:47 AM
I've had great luck, though, with an old 8mm Plossl if I remember to take it out. It's like looking through a soda straw after the Nagler, and the precision goes way up.
One other note, if you use a low power/wide field eyepiece for finding the star, and switch to high power on the star for centering, don't change the focus on most SCTs between stars. The mirror shift will kill the effort.
Posted 05 September 2008 - 10:54 AM
I use the guider display to center stars during alignment. After the 3 star align, it's quite normal for slews and goto commands to land things within the fov of the guidescope.
Posted 05 September 2008 - 02:04 PM
At any rate, the 3 star was my best alignment routine.
Posted 05 September 2008 - 02:51 PM
I also get very good goto with two star alignment. I have not really tried one star.
I seem to have problems with the PAE (sync routine), for some reason it thinks Jupiter is Saturn and when trying a star it reads that star but when I tell it to go to the star after the PAE (its still on the star I am just testing to see if its set, it moves off the star!
I have to say I had the EQ5 with version one (when they first came out) and the goto was much worse then the newer version with the Atlas. I believe there is still room to improve the goto on the mounts especially when using wider reference stars. A better sync routine would help a lot. The EQMOD improves the mounts when using a PC by bypassing the handset so hopefully the handset computer will get improved in time.
Posted 05 September 2008 - 04:16 PM
I have experienced that also. What it the correct procedure for PAE. Do you always have to clear the previous. I get the object centered and then do a PAE and it tells me It's centereing it...is that it or is there more to it.
Posted 05 September 2008 - 07:12 PM
Posted 05 September 2008 - 08:01 PM
What it the correct procedure for PAE. Do you always have to clear the previous.
Sems to me that unless you have a permanent setup you'd have to clear out the PAE every time, or maybe drift align to the same precision every time.
Typically your mount is not going to be aligned exactly the same from session to session otherwise - and if this is the case then how could PAE be expected to work properly between sessions?
FWIW, I always clear the data between sessions - I've never attempted to re-use it.
Posted 06 September 2008 - 09:35 AM
For SynScan, the sky is broken up into 88 regiors. Not sure what happens under the hood if a duplicate PAE is used for the same object; my assumption is that it adds to the "list", since the azimuth/elevation have changed, one purpose of PAE is to correct mount behaviors in the specific region associated with the PAE object at the time of PAE, and the same object may cross a boundary into a new zone. I've seen it happen during some outreaches when I use PAE on an object in case I need to come back to it. For some time, the returns will be dead perfect. Later on, GOTOs to the part of the sky where the original object used to be are very good; GOTOs to the old object are not as precise as previously. This actually can help in some cases, like when I'm looking at galaxie groups that sweep through the same piece of sky.
Until a new stellar alignment is performed, it adds to the current PAE set if an object in a new section of sky is chosen, even if the power is cycled, to keep refining the GOTOs for setups that haven't been moved or relocated. Stellar alignment (and, presumably, current PAE) is not saved if Park isn't used prior to shut down.
Posted 08 September 2008 - 04:18 PM
Posted 08 September 2008 - 05:15 PM
Posted 08 September 2008 - 09:06 PM
I use a 5mm illuminated reticle eyepiece. (quite often, I have to switch back and forth with a wide field).
Posted 09 September 2008 - 07:36 AM
Posted 09 September 2008 - 09:54 AM
If you use 3 stars in the same hemisphere, the mount will not calculate cone error.
I had an original EQ6 and even with the old Firmware, the 3 Star worked best.
Also, I aligned using a Telrad (I still do even with my C14 many times, though with THIS scope, it sometimes helps to use a 31mm Nagler). Always got excellent pointing simply by sticking the stars in the center of the Telrad Reticule...
Posted 23 May 2009 - 09:31 PM
Just to chime in here.
I always use 3 star and I use PHD with my guide-scope to do the alignment.
This way, I can center the mouse on the PHD screen and move the scope such that the alignment stars are always on the mouse.
Just be sure they are both pointing at the same target.
Then, I get dead on pointing.