Can’t focus Canon 80D on Orion xt10g.

[Rmdigby]

I have an extendable 2” mount I have tried at max distance away from telescope body up to min distance to telescope body and I can’t achieve focus. Am I missing something in setup or do I need a focal reducer? If so, which size (whatever units the FR are sized in)?

[Ozman]

Your problem is that you do not have enough inward focus travel, this is true of almost all Newtonian reflectors. There are two ways to solve this. You can use a Barlow which adds a whole LOT of other problems, the vast majority of people who try this give up on it quite quickly. The other is to move the primary mirror closer to the focuser. This allows you to achieve focus with the DSLR but also means that you now have to use an extension tube when visually using the scope as the mirror is now too close to bring an eyepiece into focus.

However, in all likelihood you will not want to do any AP with a DSLR using that scope anyway because of it's serious exposure limitations of the alt/az mount. You could do some very limited short exposure DSO imaging along with some decent planetary imaging with a ZWO imager using the scope. But the scope is not designed for imaging through.

[Star Dad]

ON an Alt/Az mount you should be able to take ~20 second exposures. The field will rotate (since the earth is rotating) and you will lose the "edge" of your photos. But I was pretty successful in using an alt/az until I could afford an equatorial mount which is far superior in countering the earth's rotation. At 30 pounds for the scope alone, you'll need a rather hefty EQ mount (rated at 60 pounds or so) to use it for serious AP. Hope this helps.

[jrkirkham]

I have an 80D and an Orion xt10. I don't usually take pictures through it, but when I do I use a barlow lens to get it into focus. That's mainly for lunar shots.

[Jennifer Christine]

Planetary is fine through an alt az.