First Guide Scope

[ACross]

Having taken a plunge into dedicated cameras and bought a ZWO ASI174MM-C, I am toying with the idea of guiding.  The QHY5L-II seems a very popular choice of guide camera, often fitted to a SW 80 or adapted 10X50 finderscope.  I found today that QHY have developed a mini guide scope: http://www.qhyccd.com/miniGuideScope.html  

It weighs only 120g, has a 30mm aperture and 130mm focal length (f4.3), designed for the QHY5L.  Has anyone tried one out? Would something this small be suitable for guiding a 200mm reflector with 900mm focal length?

Cheers,

Anthony

[YAOG]

If you use the usual general rule of thumb based on old technology no it is not good enough to use for your OTA. BUT this is 2016 and a lot has happened since SBIG burst on the scene in the late 80's. 

Here is some modern thinking and a calculator for you to use after you read the thinking behind the model. Go to this link: Autoguider thoughts  

This calculated results line up with real world results using modern CCD autoguiders and smaller guiderscopes. I hope this helps you!

Chip

[YAOG]

ACross,

I'm using a QHY5L II with Stellarvue's helical focuser 50mm guider in a Stellarvue clamshell with no adjusters guiding a HEQ5/Pro / Sirius mount running PHD2, ASCOM, EQMOD, BYEOS, Astrotortilla, etc. The OTAs being used are an ES 80mm APO and Celestron EdgeHD 8. This works well enough that I'm going to go to the 30mm objective 130mm f/4.3 QHYCCD mini guidescope for autoguiding and see if it can match the SV 50mm guidescope performance. It seems like it should and my hunch may be born out by the calculated results and the results of the mono guidescope prototype testing.

Chip

 

[ACross]

Hi Chip

Thank you for your reply, I have not been logging onto SGL for a few months and have only seen your comments now.

Since I posted Astrofest tempted me to buy a 60mm guidescope with a helical focus but this seems to top the weight of my mount with everything onboard.    I would be very interested to see how you get on with the mini guidescope as I have the same mount but loaded with the Orion Optics VX8.

Cheers,

Anthony