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Re: [Losmandy_users] Re: ? periodic + random errors Gemin/G11


Apr 13, 2004

 


----------------------------

#20021 Apr 13, 2004

Hi. I want to upgrade a G-11 mount with the gemini goto system. I

have read a lot of G-11 Gemini users that have had problems and

having to fine tune their mounts right out of the box. I want to add

a Gemin system to my G-11 but I want the periodic and random errors

to be no worse then they are now ..my G-11 has the old gears. I

posted a image of this in the photo section under my e-mail name.

Coopersx@.... Any users familiar with this please have a look

and let me know if this is good,better or worse then the current G-11

with the new worms. I am afraid that by adding the Gemini I may not

be able to acheive this type of worm/gear alignment again. The image

is a 5 min exposure with the G-11 mount misaligned from the pole. PEC

correction was off,Baclash compensation was of, and the mount ran for

5 minutes at sidereal rate. Please have a look at the star trails and

let me know if this is a good low error ...I have nothing to comapre

with and do not know what this is supposed to look like. Are some of

the mounts available today after being fully adjusted by the user

better or worse then this. I am afraid that after installing the

Gemini system it will affect my peiodic and random errors...and I

really do not want to have to go inside and start playing around and

testing if I dont have to.BTW these are the old gears. The 5 min

image is at coopersx on the photos page. Thanks Wayne



----------------------------

#20028 Apr 13, 2004

You're welcome :-)



Remember to align your camera so that RA is horizontal and DEC

vertical in your image orientation. This way, all recorded errors in

X will be RA, and all Y will be DEC. Recorded DEC errors are also

useful in estimating seeing fluctuations, since there should be no

periodic error in DEC.



Good luck,



-Paul



--- In Losmandy_users@yahoogroups.com, "Wayne Cooper" coopersx@c...>

wrote: > EXCELLENT!!! I see. I will double check to make sure no

tightspots > exist...i assume i will notice a change in speed/sound coming from

> the motors at those tighter areas if they exist(or at worse,a

stall). > And for Ccdsoft. I

> saw the log tracking errors function with Ccdsoft, but was unaware

of > DISABLING the mount in both axis to prevent autoguiding. I think I

> now know what I need to know ...and can establish a baseline before

> making any changes to my mount. Thanks a lot for your help.

Sincerely >

Wayne >



----------------------------

#20029 Apr 13, 2004

Sorry about keeping this thread so long. In checking for proper

camera orientation.Let me know if i am taking the following steps

correctly. 1ST-insert camera and take a quick pic. 2ND-using the hand

controler..move the scope in the east west direction(X-axis) and make

sure the image moves hoizonitally with the ground. 3RD step-do the

same with the north south direction(Y-AXIS). and make sure the image

moves straight up and down...90 degree perpindicular to the ground.Is

this the proper camera orientaion necessary?. If not... would

inserting a

reticle eyepiece and confirm proper movement with the hand

controller...then orient camera aprrximatley the same orientation as

the eyepiece reticle suffice? Sorry one other question on this...I am

now using a Sbig ST2000XM camera. All Sbig camera manuals show the

camera oriented in the eyepiece of the scope in what appears to be an

upside down position...with all the cableing facing the sky. That

is

how I insert my camera anyway so that I can attach the cables toward

the center of my ota...without affecting the balnce as severely

as just dangling...and also can image longer near the zenith ,since

this gives a few more inches of play before the camera hits the

mount. Would just inserting the camera in the scope in this manner =

the proper x/y orientation.The OTA would be siting on the mount

facing north with the counter weight bar down. Thanks a gain and

sorry so long. Wayne --- In Losmandy_users@yahoogroups.com, "Paul K"

pkane2001@h...> wrote: > You're welcome :-)

>

> Remember to align your camera so that RA is horizontal and DEC

> vertical in your image orientation. This way, all recorded errors

in > X will be RA, and all Y will be DEC. Recorded DEC errors are also

> useful in estimating seeing fluctuations, since there should be no

> periodic error in DEC.

>

> Good luck,

>

> -Paul

>

> --- In Losmandy_users@yahoogroups.com, "Wayne Cooper"

coopersx@c...> > wrote:

> > EXCELLENT!!! I see. I will double check to make sure no

> tightspots

> > exist...i assume i will notice a change in speed/sound coming

from > > the motors at those tighter areas if they exist(or at worse,a

> stall).

> > And for Ccdsoft. I

> > saw the log tracking errors function with Ccdsoft, but was

unaware > of

> > DISABLING the mount in both axis to prevent autoguiding. I think

I > > now know what I need to know ...and can establish a baseline

before > > making any changes to my mount. Thanks a lot for your help.

> Sincerely

> >

>

Wayne > >







----------------------------

#20030 Apr 13, 2004

It's best to do it with the camera on the telescope, not an eyepiece.



Keep rotating the camera a little at a time, and then try moving the

mount in RA to see if you got closer to having the star move

horizontally.



You only need to orient it so that RA moves horizontally. It's ok if

it moves a few pixels up or down - that will not affect the reading

too much. When you have it lined up horizontally, the Y axis will

automatically be aligned vertically, as it should be perpendicular to

your X axis :-)



This is done mostly for convenience. You can calculate the PE even

with the camera not aligned at all, but it'll require more

complicated calculations.



Regards,



-Paul



--- In Losmandy_users@yahoogroups.com, "Wayne Cooper" coopersx@c...>

wrote: > Sorry about keeping this thread so long. In checking for proper

> camera orientation.Let me know if i am taking the following steps

> correctly. 1ST-insert camera and take a quick pic. 2ND-using the

hand > controler..move the scope in the east west direction(X-axis) and

make > sure the image moves hoizonitally with the ground. 3RD step-do the

> same with the north south direction(Y-AXIS). and make sure the

image > moves straight up and down...90 degree perpindicular to the

ground.Is > this the proper camera orientaion necessary?. If not... would

> inserting a

> reticle eyepiece and confirm proper movement with the hand

> controller...then orient camera aprrximatley the same orientation

as > the eyepiece reticle suffice? Sorry one other question on this...I

am > now using a Sbig ST2000XM camera. All Sbig camera manuals show the

> camera oriented in the eyepiece of the scope in what appears to be

an > upside down position...with all the cableing facing the sky. That

> is

> how I insert my camera anyway so that I can attach the cables

toward > the center of my ota...without affecting the balnce as severely

> as just dangling...and also can image longer near the zenith ,since

> this gives a few more inches of play before the camera hits the

> mount. Would just inserting the camera in the scope in this manner

= > the proper x/y orientation.The OTA would be siting on the mount

> facing north with the counter weight bar down. Thanks a gain and

> sorry so long. Wayne --- In Losmandy_users@yahoogroups.com, "Paul

K" > pkane2001@h...> wrote:

> > You're welcome :-)

> >

> > Remember to align your camera so that RA is horizontal and DEC

> > vertical in your image orientation. This way, all recorded errors

> in

> > X will be RA, and all Y will be DEC. Recorded DEC errors are also

> > useful in estimating seeing fluctuations, since there should be

no > > periodic error in DEC.

> >

> > Good luck,

> >

> > -Paul

> >

> > --- In Losmandy_users@yahoogroups.com, "Wayne Cooper"

> coopersx@c...>

> > wrote:

> > > EXCELLENT!!! I see. I will double check to make sure no

> > tightspots

> > > exist...i assume i will notice a change in speed/sound coming

> from

> > > the motors at those tighter areas if they exist(or at worse,a

> > stall).

> > > And for Ccdsoft. I

> > > saw the log tracking errors function with Ccdsoft, but was

> unaware

> > of

> > > DISABLING the mount in both axis to prevent autoguiding. I

think > I

> > > now know what I need to know ...and can establish a baseline

> before

> > > making any changes to my mount. Thanks a lot for your help.

> > Sincerely

> > >

> >

>

Wayne > > >



----------------------------

#20042 Apr 14, 2004

If you open the shutter on the camera and turn off your drive for about

15 seconds

you will get a star track going from east to west. Adjust the camera so

the star track

is horizontal. That should get you close enough for what you are trying

to do.



If you want to be very, very precise, there are ways to measure camera

rotation.



Jim Jones



Wayne Cooper wrote:

>Sorry about keeping this thread so long. In checking for proper

>camera orientation.Let me know if i am taking the following steps

>correctly. 1ST-insert camera and take a quick pic. 2ND-using the hand

>controler..move the scope in the east west direction(X-axis) and make

>sure the image moves hoizonitally with the ground. 3RD step-do the

>same with the north south direction(Y-AXIS). and make sure the image

>moves straight up and down...90 degree perpindicular to the ground.Is

>this the proper camera orientaion necessary?. If not... would

>inserting a

>reticle eyepiece and confirm proper movement with the hand

>controller...then orient camera aprrximatley the same orientation as

>the eyepiece reticle suffice? Sorry one other question on this...I am

>now using a Sbig ST2000XM camera. All Sbig camera manuals show the

>camera oriented in the eyepiece of the scope in what appears to be an

>upside down position...with all the cableing facing the sky. That

>is

>how I insert my camera anyway so that I can attach the cables toward

>the center of my ota...without affecting the balnce as severely

>as just dangling...and also can image longer near the zenith ,since

>this gives a few more inches of play before the camera hits the

>mount. Would just inserting the camera in the scope in this manner =

>the proper x/y orientation.The OTA would be siting on the mount

>facing north with the counter weight bar down. Thanks a gain and

>sorry so long. Wayne --- In Losmandy_users@yahoogroups.com, "Paul K"

>pkane2001@h...> wrote:

>

>

>>You're welcome :-)

>>

>>Remember to align your camera so that RA is horizontal and DEC

>>vertical in your image orientation. This way, all recorded errors

>>

>>

>in

>

>

>>X will be RA, and all Y will be DEC. Recorded DEC errors are also

>>useful in estimating seeing fluctuations, since there should be no

>>periodic error in DEC.

>>

>>Good luck,

>>

>> -Paul

>>

>>--- In Losmandy_users@yahoogroups.com, "Wayne Cooper"

>>

>>

>coopersx@c...>

>

>

>>wrote:

>>

>>

>>>EXCELLENT!!! I see. I will double check to make sure no

>>>

>>>

>>tightspots

>>

>>

>>>exist...i assume i will notice a change in speed/sound coming

>>>

>>>

>from

>

>

>>>the motors at those tighter areas if they exist(or at worse,a

>>>

>>>

>>stall).

>>

>>

>>>And for Ccdsoft. I

>>>saw the log tracking errors function with Ccdsoft, but was

>>>

>>>

>unaware

>

>

>>of

>>

>>

>>>DISABLING the mount in both axis to prevent autoguiding. I think

>>>

>>>

>I

>

>

>>>now know what I need to know ...and can establish a baseline

>>>

>>>

>before

>

>

>>>making any changes to my mount. Thanks a lot for your help.

>>>

>>>

>>Sincerely

>>

>>

>Wayne

>

>







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