zwo oag v celestron oag

[iwols]

Just wondered if any body had tried both of these,ive got the zwo one at the minute,but have to use it at 5 secs most of the time and even then it loses stars easily, using it with a c8 edge and .7 x reducer,just wondered if the celestron one were much better?

[scotty38]

Let me start out by saying "I have no idea" but having read about OAG and long focal length scopes etc etc etc I am guessing changing the OAG itself is not going to fix your issues and it's more likely to be configuration. Just my 2p though 🙂

[michael8554]

The Celestron has a bigger prism - 12.5mm versus 8mm for the ZWO.

So if your Guidecam sensor is big enough the Celestron should offer more guidestars.

The Celestron is much thicker than the ZWO, needs to be factored into your 0.7 Reducer's Backspace.

Michael

[iwols]

thanks im using an asi290 guidecam

[Stefek]

I have both ZWO and Celestron. Both of them have pros an cons.  ZWO is thin/short and suited more for shorter FLs and systems with short back focus. Celestron is made for long FLs, it is large and rigid, with large prism . To fully benefit from it , a guiding camera with large sensor is required.  I am using it with my Edge HD 800 and was never in situation that there was no suitable stars for guiding.  Tried to use ZWO with Edge HD few times and it did not work every time. 

In short, for long FLs (around 2m and above) an OAG with large prism and sensitive camera with sensor size that matches the size of prism is the safest way to go

[iwols]

6 hours ago, Stefek said:

I have both ZWO and Celestron. Both of them have pros an cons.  ZWO is thin/short and suited more for shorter FLs and systems with short back focus. Celestron is made for long FLs, it is large and rigid, with large prism . To fully benefit from it , a guiding camera with large sensor is required.  I am using it with my Edge HD 800 and was never in situation that there was no suitable stars for guiding.  Tried to use ZWO with Edge HD few times and it did not work every time. 

In short, for long FLs (around 2m and above) an OAG with large prism and sensitive camera with sensor size that matches the size of prism is the safest way to go

thanks my fl is 1422 at the minute which camera are you using to guide

[Stefek]

4 hours ago, iwols said:

thanks my fl is 1422 at the minute which camera are you using to guide

Sometimes ASI174 mini, (very sensitive, but bit big pixel for 2m FL, so binning 2x2) sometimes Altair 178 which has smaller pixel but is less sensitive. 

If you'll be buying a guiding camera, my suggestion is buy "mini" version camera, with 1,25" body, as this gives you a lot of freedom for focusing with OAG