I recently put together an autoguiding setup for use with camera lenses 135mm and wider using the normal ASI290mm as a guide camera.
The goal was to keep weight to a minimum and to keep components to a minimum. Aside from the guide camera, this kit is only 3 pieces.
I typically use a ballhead mounted to a dovetail plate when I dslr image so this setup breaks down to a very small easy and fast to setup package.
First I acquired a small 1/4' threaded ballhead which mounts onto a threaded hotshoe adapter
Since the asi290 is threaded for 1/4-20, it just screws onto the ballhead. The ballhead will swivel and pivot unless locked down which makes it easy to square up. This ballheads payload is not listed but you can tell that the weight of the camera and lens is easily locked solid into place when operating the lock mechanism.
The guiding lens is a Fujian 50mm F1.4. It comes with a hood and spacers. the ASI290 comes with a cmount adapter.
the lens makes focusing on stars super easy and you can use the aperture to reduce light and sharpen up stars instead of using camera gain to get longer guide exposures.
You can use this calculator to determine if this setup will work for you https://astronomy.to...ope_suitability
Here is the lens https://www.ebay.com...5?ul_noapp=true
Its a pretty nice setup for around $50, super light and lets me do long 10 minute exposures without worry of elongated stars. Polar alignment in sharpcap seems to have worked well also, there is no noticeable drift after 4 hours, only artifacts at the edges from dithering.