seeker372011
scholastic sledgehammer
Reged: 03/05/04
Posts: 782
Loc: Sydney , Australia
|
|
maybe PEC training will help reduce the amplitude in RA ?
--------------------
ETX 70,ED 80 on a CG5 Mount;Orion Star Shoot Deep Sky Imager,Canon 300D modded;20 x 80 LW Obies;PST;10 inch GSO dob
|
Bill W.
Pooh-Bah
Reged: 10/09/05
Posts: 1437
Loc: Western PA, USA
|
|
Quote:
well reporting back from the results of last night-I can't replicate it tonight as the weather is awful..the mount certainly autoguided and though I clearly still have problems in RA its not going out of control as it was the other night
I still need to find out what is causing the problems in RA but in the meantime I am happy to report that autoguiding did its best to bring the process back under control..thanks Bill.
I'm very glad I could help your 'ping-ponging' problem...  I'll save someone else from asking.... On your graph, is the scale is pixels or what? How is the balance in RA? What focal length are you shooting at? What is your aggressiveness on for guiding? Good luck, I hope you get everything figured out and fixed!
-Bill
--------------------
Orion Atlas EQ-G (EQMOD), SBIG ST-2000XM & AO7
Stellarvue SV66ED
Skunk Hollow Observatory
|
Charlie Hein
Postmaster
Reged: 11/02/03
Posts: 6534
Loc: 26.06.08N, +80.23.08W
|
|
I believe that it's pixels and samples like the first one he did.
Charlie
--------------------
Weston CSC:
|
seeker372011
scholastic sledgehammer
Reged: 03/05/04
Posts: 782
Loc: Sydney , Australia
|
|
yes its samples and pixels as Charlie pointed out.
The balance in RA is just slightly to the East..maybe it needs to be heavier to the east? Guiding agressiveness is 110..it didnt seem to work at 100%.
I would hope to be shooting at 900mm with my (also) brand new (Meade clone) ED127
thanks for the help
Narayan
--------------------
ETX 70,ED 80 on a CG5 Mount;Orion Star Shoot Deep Sky Imager,Canon 300D modded;20 x 80 LW Obies;PST;10 inch GSO dob
|
Bill W.
Pooh-Bah
Reged: 10/09/05
Posts: 1437
Loc: Western PA, USA
|
|
I don't use PHD to guide. I use MaximDL to guide a DSI Pro. But, I know in MaximDL, 10 is 100%. I usually have mine set to 4. I only have MaximDL making 40% of the corrections it thinks it needs to. I'm wondering if PHD is setup the same way. Maybe you should try 40%. Some mounts like 40% ... some mounts guide better at 80%. I'm not familiar enough with my Atlas at longer focal lengths to offer an accurate suggestion on what will probably work best. I use 40%... I'd say experiment with the aggressiveness on the guiding. Again, you may be chasing seeing, etc. more so at higher correction percentages. I definitely wouldn't use 110% unless PHD is setup vastly different than MaximDL, etc. are.
-Bill
--------------------
Orion Atlas EQ-G (EQMOD), SBIG ST-2000XM & AO7
Stellarvue SV66ED
Skunk Hollow Observatory
|
seeker372011
scholastic sledgehammer
Reged: 03/05/04
Posts: 782
Loc: Sydney , Australia
|
|
The default RA aggessiveness in PHD is 100; at 100 it wasn't able to bring the guide star back; the maximum aggressiveness is 120; trial and error led me to to 110.
I think the minimum in PHD -is 80 or 85-from memory
Narayan
--------------------
ETX 70,ED 80 on a CG5 Mount;Orion Star Shoot Deep Sky Imager,Canon 300D modded;20 x 80 LW Obies;PST;10 inch GSO dob
|
Bill W.
Pooh-Bah
Reged: 10/09/05
Posts: 1437
Loc: Western PA, USA
|
|
Is tracking sidereal? What focal length are you shooting at? 6-10 pixel errors are bad at 400mm but not as bad at 1500mm if you understand what I'm saying.
-Bill
--------------------
Orion Atlas EQ-G (EQMOD), SBIG ST-2000XM & AO7
Stellarvue SV66ED
Skunk Hollow Observatory
|
seeker372011
scholastic sledgehammer
Reged: 03/05/04
Posts: 782
Loc: Sydney , Australia
|
|
YOf course you are right Bill -this performance from the mount/autoguideris actually ok if I were shooting using my ED80 ( 600mm focal lentgh) and William Optics 0.8 focal reducer. I did actually hook a camera-a QHY8- on this scope/reducer combo Saturday night and shot about two hours worth of 10 minute subs that I have yet to process-but a quick look at the raw frames suggests no noticeable star trails.
Won't fly with the ED 127 at 900 mm focal length I suspect, though
Narayan
--------------------
ETX 70,ED 80 on a CG5 Mount;Orion Star Shoot Deep Sky Imager,Canon 300D modded;20 x 80 LW Obies;PST;10 inch GSO dob
|
Bill W.
Pooh-Bah
Reged: 10/09/05
Posts: 1437
Loc: Western PA, USA
|
|
At 400mm I rarely see my error over 1. It usually is .5 or less. You were seeing 6-10 pixel errors at 480mm? But, the advantage we have in the north is polaris. Polaris makes it very easy to get a decent polar alignment fairly quickly. Maybe your polar alignment exacerbated your guiding problem last time out since you said it wasn't as good. Time will tell.
-Bill
--------------------
Orion Atlas EQ-G (EQMOD), SBIG ST-2000XM & AO7
Stellarvue SV66ED
Skunk Hollow Observatory
|
seeker372011
scholastic sledgehammer
Reged: 03/05/04
Posts: 782
Loc: Sydney , Australia
|
|
yes when I looked at the image I collected there were star trails...however my guide scope is 900mmm focal length-so the errors are at 900 mm-while my imaging scope is at 480 mm which should allow for some error in polar alignment. having said that I used to routinely shoot 20 minute subs with my CG5/ED80 and the same guide scope, so my polar alignment technique is acceptable at least at the 480 to 600mm focal length
more work on the EQ6 required methinks
Narayan
--------------------
ETX 70,ED 80 on a CG5 Mount;Orion Star Shoot Deep Sky Imager,Canon 300D modded;20 x 80 LW Obies;PST;10 inch GSO dob
Edited by seeker372011 (08/11/08 06:28 AM)
|
Bill W.
Pooh-Bah
Reged: 10/09/05
Posts: 1437
Loc: Western PA, USA
|
|
I just happen to think from your last post... my guide errors are at 700mm not 400mm. I am shooting at 400mm and guiding at 700mm. I usually use a 2 second guide exposure so I'm not chasing seeing. You definitely do have an issue that may be beyond your control. I'm ordering a C6 SCT shortly, so I'll see how the Atlas guides at 1500mm.
-Bill
--------------------
Orion Atlas EQ-G (EQMOD), SBIG ST-2000XM & AO7
Stellarvue SV66ED
Skunk Hollow Observatory
|
Dennis Sakva
Pooh-Bah
Reged: 10/19/04
Posts: 1060
Loc: Kiev, Ukraine
|
|
Actually the last graph is terrible. The DEC graph shows atmosphere turbulence, while the RA shows irregularities in wormwheel/worm. Those are high frequency and pretty bad, I must say.
I would do a disassemble/relubing/reassemble procedure. To make sure that worm bearings are not overly tightened, worm and wormwheel are in good contact and at a correct distance from each other.
EQ6 groups at groups.yahoo.com delas with problems like this.
|
seeker372011
scholastic sledgehammer
Reged: 03/05/04
Posts: 782
Loc: Sydney , Australia
|
|
Quote:
Actually the last graph is terrible. The DEC graph shows atmosphere turbulence, while the RA shows irregularities in wormwheel/worm. Those are high frequency and pretty bad, I must say.
I would do a disassemble/relubing/reassemble procedure. To make sure that worm bearings are not overly tightened, worm and wormwheel are in good contact and at a correct distance from each other.
EQ6 groups at groups.yahoo.com delas with problems like this.
OMG
That is what I was terrified I would hear.
I am not the most handy guy and major surgery may well be out of my capabilities.
I wonder if this sort of thing is covered by warranty
--------------------
ETX 70,ED 80 on a CG5 Mount;Orion Star Shoot Deep Sky Imager,Canon 300D modded;20 x 80 LW Obies;PST;10 inch GSO dob
|
Previous
Index
Next
Threaded
[Re: 
Edit
Reply
Quote
