11 replies to this topic

[raging_scotsman]

Hi everybody!

I’m wondering if anyone is using the ZWO EAF autofocuser with an Edge Hd 8 and having good results with imaging. I was looking at the Moonlight CHL as it comes highly recommended, but these seem hard to get a hold of. The ZWO EAF is easy to find and fits the budget better.

I’m concerned about mirror flop since I won’t be able to lock down the primary, mostly. And generally I just want to hear your experience with this gear.

I just got the scope, and will be adding autofocus, off-axis guiding, and am planning to move on from DSLR imaging to a cooled CMOS, possibly the older 1600MM or the 294MM, plus filter wheel and all that jazz. If I can get away with the ZWO EAF as an autofocus option then I’ll go that route, but I’d hate for it to cause me too many limitations I can avoid once I spend all the cash I’m looking at blowing. What a money pit, ha ha.

Thanks!

Edited by raging_scotsman, 26 March 2023 - 10:58 AM.

[hyiger]

I use the EAF with my C11. It was a PITA switching focus between f/7 and f/25 until ZWO updated the firmware to allow a larger focuser count.

 

As far as mirror flop is concerned it should (I think) be minimal on an Edge as long as the mirror is locked. You can keep the mirror locked and change focus with a Crayford style focuser and the EAF instead. 

 

Also, getting decent results on a long focal length SCT is going to be a challenge. Which mount do you intend to use it with? If you are on an Evolution mount then you need to purchase a wedge or defork and use on an decent EQ mount. 

Edited by hyiger, 26 March 2023 - 11:19 AM.

[DirtyRod]

I used one for about six months and it was fine. Moved it to my refractor and changed to a Celestron so I could use the HC for focusing when doing visual. No issues and the ZWO performed about the same as the Celestron.

 

Mirror flop and tilt are a bit of an issue for me but I minimized it by refocusing every hour as part of my sequence. Just make sure you leave at least an hour to acclimate. I run pretty much the same rig and strongly suggest the 174 as your guiding cam. The reducer clips the FOV on the 8” by about 40% so you need all the sensor in the guide cam you can get.

Edited by DirtyRod, 26 March 2023 - 12:29 PM.

[jonnybravo0311]

I have the 8" EdgeHD with the ZWO EAF. Works fine. You just need to ensure your final focus is a counter-clockwise turn of the knob. This pushes the primary mirror up the tube (i.e. towards the corrector plate, away from the camera). I use NINA and have the autofocus options set to use overshoot. So, if my focuser needs to move in a clockwise direction, the software moves it much further than necessary, then turns the focuser counter-clockwise to get back to where it needs to be.

[heydave]

I have the 8HD and use the ZWO EAF, and it works very well. I gave up on the OAG however. I just couldn't get it to consistently track. I use a 70mm guide scope with a 174, and tracking is great. You just have to get the ZWO adapter to connect the EAF to the 8HD. Was not difficult to do. 

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[raging_scotsman]

I use the EAF with my C11. It was a PITA switching focus between f/7 and f/25 until ZWO updated the firmware to allow a larger focuser count.

 

As far as mirror flop is concerned it should (I think) be minimal on an Edge as long as the mirror is locked. You can keep the mirror locked and change focus with a Crayford style focuser and the EAF instead. 

 

Also, getting decent results on a long focal length SCT is going to be a challenge. Which mount do you intend to use it with? If you are on an Evolution mount then you need to purchase a wedge or defork and use on an decent EQ mount. 

I’ve thought about a crayford focuser but haven’t looked much into options yet. Might run close in price to the CHL if I did that and the EAF in the end… well maybe for a used CHL. Locking the mirror would certainly be ideal.

 

as for a mount I’ll be using the scope with an EQ6-R Pro, so should be all good there. I still expect a challenge due to the added weight and longer focal length vs my refractor but I knew I was getting into that. I’m a sucker for punishment.

[raging_scotsman]

I used one for about six months and it was fine. Moved it to my refractor and changed to a Celestron so I could use the HC for focusing when doing visual. No issues and the ZWO performed about the same as the Celestron.

 

Mirror flop and tilt are a bit of an issue for me but I minimized it by refocusing every hour as part of my sequence. Just make sure you leave at least an hour to acclimate. I run pretty much the same rig and strongly suggest the 174 as your guiding cam. The reducer clips the FOV on the 8” by about 40% so you need all the sensor in the guide cam you can get.

More than one person in this thread suggest the 174 for guiding, I’m going to look at it more closely. I guide my refractor with an Altair GP-130 and I’m… not in love with it. Good tip for acclimation, it will definitely need more time than my small scope.

[raging_scotsman]

I have the 8" EdgeHD with the ZWO EAF. Works fine. You just need to ensure your final focus is a counter-clockwise turn of the knob. This pushes the primary mirror up the tube (i.e. towards the corrector plate, away from the camera). I use NINA and have the autofocus options set to use overshoot. So, if my focuser needs to move in a clockwise direction, the software moves it much further than necessary, then turns the focuser counter-clockwise to get back to where it needs to be.

 

Good tip for the counter clockwise final turn. I probably wouldn’t have thought of that. And I’ve now looked up NINA… I had no idea this software existed but I’m very excited it does. Free as well!

[raging_scotsman]

I have the 8HD and use the ZWO EAF, and it works very well. I gave up on the OAG however. I just couldn't get it to consistently track. I use a 70mm guide scope with a 174, and tracking is great. You just have to get the ZWO adapter to connect the EAF to the 8HD. Was not difficult to do. 

I have a 60 mm guide scope that I’ll maybe try with the Edge before I jump into an OAG. Worth a shot. I’ve been worried about reducing weight but I see we have the same mount, so I’m encouraged. You’re also the second person to recommend the 174, I’m going to look at it. Perhaps I’ll get that before the OAG.

[raging_scotsman]

Thanks everybody! I’m convinced at this point to order the EAF and bracket. It’s not a huge expense and I can add a crayford focuser later on if leaving the primary unlocked drives me nuts. Also learned about NINA and will be checking out the 174 for guiding. Ask for one thing and learn several more… I love this place!

 

Clear skies!

[HubSky]

It will work fine.  Just make sure the EAF is finishing its focus CCW.  I had to reverse the focus in the ASIAir app to make that happen.  The issue for me with the guide camera and OAG is the FOV.  Sometimes I couldn't find a guide star with the ASI290.  The ASI220 should be better with its larger sensor, but I don't have personal experience with it.  But the best choice is the ASI174mm mini which I use now and have never had an issue finding guide stars.  You didn't say which OAG you were getting.  I use the Celestron OAG which works really well.  Whichever you get, just make sure it has a larger prism on it such as 10-13mm.  

[Oort Cloud]

It will work fine. Just make sure the EAF is finishing its focus CCW. I had to reverse the focus in the ASIAir app to make that happen. The issue for me with the guide camera and OAG is the FOV. Sometimes I couldn't find a guide star with the ASI290. The ASI220 should be better with its larger sensor, but I don't have personal experience with it. But the best choice is the ASI174mm mini which I use now and have never had an issue finding guide stars. You didn't say which OAG you were getting. I use the Celestron OAG which works really well. Whichever you get, just make sure it has a larger prism on it such as 10-13mm.

I use the regular OAG on my C8 EdgeHD with a 174mm and it works just fine. The edges of the sensor don't get any light but I've never had trouble finding multiple guidestars using it.