SVBONYSV106 Telescope Guide Scope, 50mm F4 Focal Ratio 190mm Focal Length, Full Coating Finderscope with Helical Focuser, for Guiding Finding Stars, Compatible with ZWO QHY Auto Guide Camera

I gave this finder 4 stars, because for what it costs it is worth it. You need to remember this is not an expensive finder, with bright objects at the edge of the field you will experience both spherical and chromatic aberation to one degree or another.However, the wide field of view is excellent, the helical focuser works smoothly and gives very crisp focus, as longer as you are gentle, far better than rack and pinion types.The body is aluminium, tough and feels far better quality than the cost suggests. The mounting rings and foot are well made and have a quality about them.If you are looking for a reasonably priced finder/guidescope you would be spending wisely by buying this offering from SVBony.Just remember, if you expect aberation free images via your finder/guide, you will need to spend at least 5 times the cost of this chap.

This is very well made mechanically. Good machining quality and nicely anodised. Using the locking screws it seems to be stable enough for guiding purposes. The combination of coarse and helical focusing works nicely.Only problem with the one I received was that the objective lens (a cemented doublet) was put its the wrong way around. I discovered this when first testing the scope and being very disappointed with the image quality. Once corrected (it just screws together) all is OK.

Used as a guide scope for my EQ6 mount with a QHY5LII guide camera. Always loads of guide stars to choose from and the focal length is fine for my setup where the FL of the main telescope is 1000 mm.