OAG vs Guide Scope

[jezhughes]

I'm glad i found this thread! Have been considering an OAG for a while. i have 250 and she's a heavy girl, could do without the guidescope. have also been having flexure nightmares on my dual saddle rig which has spoilt a couple of nights

[Gina]

I'm going the OAG route now. I'm getting an NM190 next week and the consensus of opinion favours an OAG. I have opted for the new FLO one which looks like the TS one with a low profile. It will also attach to the SW 0.85x focal reducer for my ED80 I shall be using a QHY5 with it so hoping it'll all work out. I'll let you all know

[r3i]

I'm going the OAG route now. I'm getting an NM190 next week and the consensus of opinion favours an OAG. I have opted for the new FLO one which looks like the TS one with a low profile. It will also attach to the SW 0.85x focal reducer for my ED80 I shall be using a QHY5 with it so hoping it'll all work out. I'll let you all know

I've found using an OAG to be really easy and have always been able to locate a bright enough guide star. Best of luck with all your new toys and let's hope we can get some clear skies at long last.

[Gina]

I've found using an OAG to be really easy and have always been able to locate a bright enough guide star. Best of luck with all your new toys and let's hope we can get some clear skies at long last.

Thank you Mike As for the weather - it's snowing here Forecast said clear skies and hard frost - ha, ha! We can but hope...

[Tony Rodda]

Is a camera with an integral guide-chip not another alternative?

I've used a guidescope successfully for a couple of years but had considered something like an ST10XME.

Regards

Tony

[ollypenrice]

Is a camera with an integral guide-chip not another alternative?

I've used a guidescope successfully for a couple of years but had considered something like an ST10XME.

Regards

Tony

Personally I think they are an absolute pain. You have to rotate the picture frame to find a guide star, which limits your framing options. If you are doing more than one image in a night this means rotating to reframe, which takes ages and also complicates your flats situation. And finally the guide cam shoots through the filters. Not many stars show up in Ha. Nope, I can do without this bit of technology!

Olly

[Gina]

I agree - a non-starter.

[RobH]

Something to be aware of with OAG's is that if you're using, for example, a smallish chip ca,era, and the OAG pickup prism is at the edge of the scope FOV, the stars may be distorted due to coma in the OAG.....get your pickup prism as close as you can to the FOV you're imaging.....a bit of distortion of the star shapes isn't an issue, but a lot can make it hard for the software to define the centre of the guide star.

Re. Lodestars/connections....I have 2 and find them fine. All I do is loop the USB cable back down the barrel of the camera and secure it with a velcro strap.

That said, I do wish that astro manufacturers would provide waterproof and strain proof screw on connections for their cables.....somewhere I saw a thread where a chap had removed all of his USB plugs and replaced them with XLR's....much better, and there are small plugs/sockets of a similar type available (LEMO connectors for example)

Returning to ease of use, I sometimes struggle to find a guidestar at long FL's away from the galactic plane, but a few compromises with framing usually solve this. I must admit though, that if you can deal with any differential flexure issues, I prefer a guidescope.