First time guiding, how does this look?

[cuivenion]

I tried guiding for the first time last night as it was hazy and the moon was out, so I wasn't going to be doing any noteworthy observing anyway. Heres the logs, I only managed a short guiding session on Betelgeuse due to to clouds rolling in. I'd have managed something on a different target but I started to have trouble with my gotos so I called it a night:

Like a lummox I didn't get an image of Betelgeuse but the previews of the 120s subs were better than I'd had unguided. Please give me your thoughts on the logs above and let me know if there's anything I can improve. Guidescope was a Scopeteknix 50mm Big Eye with a PS3 Eye camera. It was 1.5x barlowed. It was guiding an AstroEQ Vixen GP with a Skywatcher Explorer 130p. I was using an Altair GPCAM for the main cam.

A couple of questions. How crucial is the guidescope focal length? I'm not sure of the Big Eye's focal length and I'm not sure if the barlow is working at exactly 1.5 times. I've estimated the Big Eye at 220, so I've estimated the total FL at about 320, as the barlow is quite close to the chip.

 

[Pompey Monkey]

Doesn't look to shabby.

I'd ditch the barlow if I were you: It just adds an extra complication to the mix and you'd be surprised at how good PHD is at determining the centroid of the guide star, even at pixel scales much bigger than yours.  

[cuivenion]

Unfortunately I can't get it to focus without the barlow. I can use my Skywatcher 9x50 but that has a shorter FL of 180mm giving me giving me a resolution of 6.87". I'll be trying to guide a resolution of 1.19", do you think that'll be OK?

[iapa]

1 hour ago, cuivenion said:

Unfortunately I can't get it to focus without the barlow. I can use my Skywatcher 9x50 but that has a shorter FL of 180mm giving me giving me a resolution of 6.87". I'll be trying to guide a resolution of 1.19", do you think that'll be OK?

Had a similar issue with my 130 Newt.

Replaced with SW f5 200mm 200P-DS which has a shorter tube to bring the focal plane further out from the OTA.

Some people have used longer bolts holding the primary mirror to move it nearer the secondary, again, brining the focal plane out from th eOTA>

There are others who shortened the tube - DIY, I don't do

In the middle of setting up, but will loot out something relevant a wee bitty later on,.

[cuivenion]

2 minutes ago, iapa said:

Had a similar issue with my 130 Newt.

Replaced with SW f5 200mm 200P-DS which has a shorter tube to bring the focal plane further out from the OTA.

Some people have used longer bolts holding the primary mirror to move it nearer the secondary, again, brining the focal plane out from th eOTA>

There are others who shortened the tube - DIY, I don't do

In the middle of setting up, but will loot out something relevant a wee bitty later on,.

Hi, It's the guidescope that won't focus with the PS3 Eye camera. The 130p is fine with the gpcam. Thanks for the advice though. Have a good night!

[kens]

The graph looks pretty good for a Vixen GP. But I always recommend to post the actual guide log for deeper analysis. You calibration looks good. You should run the guiding assistant for advice on settings. I particular you are using quite a short exposure time on the guider. Try 2-3 seconds instead of 1 second - the guiding assistant will advise on this too.

The run is a bit short to say much more. It is better to have 2 or 3 worm cycles in duration. 

 

[cuivenion]

Awesome, can't wait to actually do some imaging with it!