My Apertura AD12 is not reaching focus with ZWO camera

[TheButcher]

Hey all,

I seem to be having an issue with my new (used) Apertura AD12 when I try hooking up my 290mm to it. For some reason, it is not reaching focus. I tried 3 different 1.25" barlows (Antares 1.5x, Baader 2.25x, and GSO 2x). Now I can put an eyepiece in and I have no issues 1.25" and 2".

I took out the 2" to 1.25" adapter and put my camera closer into the focuser (About a half-inch closer and was able to see the stars on my laptop. So it seems like the 2" to 1.25" adapter is causing it to be too far back or maybe the focuser flange is too high for it? I also have a Z8 Dob and have not had this issue, along with my AD10 Dob that I sold last year.

Now on the brighter side of things. I bought a GSO Coma Corrector and a pair of rings and a Losmandy 24" Plate as I intend to use it for Lunar and Planetary. But the main reason for the Coma corrector was to try to do small exposure times like 30-40 seconds to capture some stuff while I had the scope up there for fun and only because I would not feel like taking the scope off the mount after the moon passes out of my backyard view. But to my surprise, the GSO Coma Corector hooked up to my 1600mm-P with filter wheel and 75mm of back distance was able to reach focus no problem at all, and I even had to back focus halfway.

Also the GSO coma corrector comes with a 2" adapter that can screw on to it, so you can put an eyepiece, now with that said, can I add my Camera and a Barlow to it. And if it works out, would that cause any issues or loss of quality?

Thanks in Adanced

Here are 2 photos of my setup in case anyone wants to see how it is mounted and check out my Dob Dolly I made. I just got the Tri-Pier the other day and the mount is a CEM 70. I haven't tested it, because it needs another counter weight. 2 21lb counterweights did not do the trick so I ordered another 21lb to be sure and so I can have them up higher for more stablity.

[SkyHiker]

That's impressive! I have a Z12 and can reach focus with a Baader CC and a mirrorless Fuji DSLR. Earlier efforts required moving the mirror up by longer collimation screws but that was before I had the Fuji. I never contemplated putting it on my G11S but ordered a 12" F/4 TPO instead especially to be fast. On October 1, it should be here any time now. I will try that for planetary as well, either with a 5x Barlow or afocally zoomed in with an ELPH. If I eve try AP with my Z12 it will be on my DIY EQ platform that is dual axis and autoguided, a true balancing act. I wonder how you get up at the eyepiece. Those are some impressive rings.

[TheButcher]

That's impressive! I have a Z12 and can reach focus with a Baader CC and a mirrorless Fuji DSLR. Earlier efforts required moving the mirror up by longer collimation screws but that was before I had the Fuji. I never contemplated putting it on my G11S but ordered a 12" F/4 TPO instead especially to be fast. On October 1, it should be here any time now. I will try that for planetary as well, either with a 5x Barlow or afocally zoomed in with an ELPH. If I eve try AP with my Z12 it will be on my DIY EQ platform that is dual axis and autoguided, a true balancing act. I wonder how you get up at the eyepiece. Those are some impressive rings.

Thanks, I got the rings from Agena for $99. They seem pretty solid and are pretty light (my guess 2-3 lbs for both) and the 24" Plate weighs about 4.5 lbs. So my guess is that the total weight without a camera is about 53-54 lbs. But I could probably lose 2 lbs by taking the Alt Bearings off. I am pushing the mount abit, but when I have it up there it will be for Lunar/Planetary and to see how long exposures I can get away with it.

As far as reaching the eyepiece, I don't think I will use it visually when mounted or I could always turn it so the eyepiece faces at a downward angle so it sticks out to the side a bit. My main reason for actually getting this Dob was for my ISS project that I am working on, but it has expanded now lol

Now for you not being able to reach focus with your Mirrorless camera with the Z12 without a Coma corrector makes me feel better. So I am thinking to just use the Coma Corrector with a Barlow since I did read in reviews that others use a Barlow with their Eyepiece. I was just shocked that the ZWO planetary camera couldn't reach it off the bat as it did with my other Dobs with plenty of back focus.

Also that 12" TPO at F4 seems real nice with the G11s. And another thing that really helped me put it on the mount was the Farpoint 12"Newt Straps I got for $30. It makes hoisting it up much easier.