GoTo accuracy

[Bigzmey]

This topic is not specific to Celestron mounts but there is no place on the forum yet to post general mount topics.

Anyhow, I want to hear from people using any brand AltAz GoTo mounts on how good is goto function is.

I only have experience with SW AzGti mount and generally new to the GoTo thing. After tweaking the settings and playing with aligment I got to the point where GoTo function always places the target within 1 deg FOV, but never in the center. In my case it is always in the low right portion of FOV.

Is that fairly typical for an AltAz GoTo mount? Or some of you getting bullseyes with your mounts?

[JCINGA]

I get the same but mine is an older LX200 Classic.
Tracks fine after centering. But slew to a new one and it’s off down and to the left.

[515bonner]

I get the same but mine is an older LX200 Classic.
Tracks fine after centering. But slew to a new one and it’s off down and to the left.

I had one of the older LX200 Classics (AltAZ mode) back in the mid 90's that did the same thing.
It always had the object in a 30' field of view but no matter what you did, when you slewed to a new object it was always to the left of center by about 10'.
Sometimes you had to manual move around because the object was just a hair out of the field of view. But it was always in the same direction.
Never could quite figure out why.

[JCINGA]

Yeah, I don’t do AP so it’s not a worry as it tracks great once centered. Great scope otherwise.

[Don Quixote]

Hello Andrey.

My experience is predominately with my little SLT mount. It is the first goto mount I used. I was always pleased that it put my target anywhere in the fov, which it did and does consistently.

I am not sure I remember for sure but I don't think it was always in the middle. But I was not really worried about it at the time.

Not much help, I know, but that's my story and I'm stickin' to it.

[Bigzmey]

Thanks everyone for the feedback!

Hello Andrey.

My experience is predominately with my little SLT mount. It is the first goto mount I used. I was always pleased that it put my target anywhere in the fov, which it did and does consistently.

I am not sure I remember for sure but I don't think it was always in the middle. But I was not really worried about it at the time.

Not much help, I know, but that's my story and I'm stickin' to it.

Mark, what scope did you use with SLT?

[Don Quixote]

Thanks everyone for the feedback!

Hello Andrey.

My experience is predominately with my little SLT mount. It is the first goto mount I used. I was always pleased that it put my target anywhere in the fov, which it did and does consistently.

I am not sure I remember for sure but I don't think it was always in the middle. But I was not really worried about it at the time.

Not much help, I know, but that's my story and I'm stickin' to it.

Mark, what scope did you use with SLT?

I had the 127 MAK mounted. I have quite a number of outings with it. I have been wanting to mount one of my fracs but gave not gotten around to it...there seems to be a new gadget for me to play with every time I turn around.

I also have the Alt/Az skywatcher but have only used it once in that mode with my 5 inch Mak and the 127 frac and I cannot remember where things landed in the fov on that one.

[BamaDon]

I've been using a celestron 8" AltAz for outreach. I've found that if I use a bubble level to ensure that the mount is level, that helps a lot.

[Lady Fraktor]

I have used the SLT mount for quite a few years, once adjusted it consistently puts objects in the field of view.
I use it primarily for the 70mm and SV80 but used it with the supplied 102mm as well.

Your results are fairly normal, do you use a reticle eyepiece when aligning?

[JayTee]

So this question has a binary with a qualifier for the answer.

Binary - Is the desired object in the field of view yes or no? If no, go back and redo the entire goto alignment. If yes, read the qualifier question.
Qualifier - is the desired object where you would like it to be in the FOV?

So if the binary is satisfied then we are only talking about the qualifier. This is where it gets a bit "dodgy". I own 3 Celestron goto mounts 2 Alt-Az (SLT & GT), 1 EQ (AVX) and 1 Meade Alt-Az (DS2000) goto mount.

The newer the technology the better and more accurate will be the gotos. My AVX has the capability to do a 2-star goto alignment then add 4 calibration stars. The gotos from this mount are almost always right in the center of the FOV. At worst they are still within the 1/3 from center FOV ring.

As for my older Alt-Az mounts, well that's a bit different. If you can get the object 1/3 of the way out from the center of the FOV, or closer, you're done, that's as good as you can expect.

If you are outside that 1/3 from center of FOV ring then there are a few things you can do that can help get you inside that ring (most of the time). First off, use a reticle EP for centering your alignment stars. For the Celestron mounts, always finish slewing to your alignment stars by using the Right and Up buttons. If you have to use the Down and or Left buttons, reposition the object so you are always finishing the slew UP and RIGHT. When you are done with your goto alignment, then accomplish the calibrate mount function. Finally, use the goto function to slew to each of your alignment stars and see if they are still centered in the FOV. If not, fix it!

Here's the dodgy part: I swear that these older Celestron Alt-Az goto mounts are very much like my teenage son when I ask him to go mow the lawn. Sometimes he does it exactly as asked. Other times he does it but does a poor job. And sometimes he just completely forgets to do it. Bribery, to get a consistent result, with money and/or food sometimes works and sometimes doesn't. After having owned these mounts for near 7 years now, they behave much the same way. You level the mount, you do the UP and RIGHT slew, you use a reticle EP with the alignment star smack dab right on the crosshairs and you really don't know what your result will be until you start using the goto function! Much like my son, maybe the encoders are just LAZY --- Sometimes!!!

I hope this somewhat helps in getting that desired object closer to FOV center.

Cheers,
JT

[Kingofthehill]

FWIW, I use GoTo with my 18UC with ArgoNavis. After initial alignment an object will appear in the field, but usually not centered. After each subsequent finding of a target I can add that object to the alignment and the next desired object will be closer to center.

[Bigzmey]

Thanks everyone! Sounds like the result I am getting is close to the expected accuracy. The only thing I have not try yet is a reticle EP. I will give it a shot next time.