William Optics All New 50mm UniGuide Scope with Slide-base - Space Gray # M-G50PB-TG

All New Slide-base UniGuide 50mm Guide Scope (with a unique 1.25 inch RotoLock camera holder). Features a black anodized Vixen/Synta-style rail (not removable) at the bottom of the finder tube for direct insertion into compatible handles on William Optics telescopes. Not for use with conventional guidescope or finder rings.

UniGuide50 specifications:

• Color: White with space gray trim (other color versions sold separately)
• Aperture: 50mm
• Focal length: 200mm
• F-ratio: f/4
• Length: 265mm
• Weight: 515g
• Extra long dewshield length: 90mm long (more effective at dew prevention)
• 1.25” Rotolock included
• Front focuser system, Focus lock ring included

Back focus Information:

Out of the box, this guidescope comes with a 1.25" Rotolock adapter/eyepiece holder. Also included separately is an M48-threaded extension tube. This extension tube can be used by itself with the optical tube instead of the Rotolock adapter, or it can be used in conjunction with the Rotolock adapter.

The required back focus of this guide scope will vary depend on the configuration you use these two items in. See photo # 3 above illustrating this. Note that the back focus numbers in the diagram below are with the M48 adapter or the Rotolock adapter fully screwed on to the finder tube. Since theses adapters can be extended by an additional 8mm as explained above, you can effectively reduce the back focus numbers in the figure by up to 8mm from those specified below by partly unscrewing whichever adapter(s) you are using.

Configuration A above can be used if your guide camera has a short nosepiece with an M48 female thread.

Configuration B above is for use with cameras that have a 1.25" nosepiece. You can slide the camera in or out manually from the Rotolock adapter for coarse focus and to place the sensor at approximately the correct location near the focal plane.

Configuration C is for use with 1.25" "Mini" or "cylinder" type cameras that are very widely used with such guidescopes. Again, you can manually slide the camera in or out to get it near focus. Depending on your camera's back focus, you may need to use a 1.25" extension tube (often included with the camera itself) to reach focus.

If your application requires an M42x0.75 T/T2 thread, you can purchase an M48-to-T thread adapter such as the Blue Fireball T-06 adapter to convert the M48 male thread on the rear of the guidescope or the included M48 adapter into a T/T2 male thread. For example, this would be useful if you wish to connect your camera featuring a female T thread directly to the guidescope for a more secure threaded connection. In another example, some people prefer to replace the included 1.25" Rotolock holder with a different 1.25" visual back (such as the ZWO 1.25" Helical Focuser # HF1.25) that allows easier fine focus control. Make sure to work out your back focus requirements carefully as you may need spacers to place the guidecam sensor at the focal plane.