Edge HD925 Imaging setup

[wornish]

I am thinking of adding a Celestron Edge HD925 to my astro gear and want to be able to use my existing ZWO ASI1600MM Pro camera and ZWO EFW that I have on my Esprit.

I also want to  include a ZWO OAG in the image train.  Anyone else done this ?  on an edge HD.     If so what extension tubes do I need to get to the correct back focus of what I believe to be 146mm.

Also I have read that you can't use electronic focusers on the HD tubes because of the mirror lock screws, is that true?

 

 

Edited May 10, 2020 by wornish

[Craney]

In answer to your last point.....  surely such an Astro-giant as Celestron would not make such a clanger....

Maybe for certain brands.... but I've seen pictures of Moonlites that are on the back of Edge optics.

[Shimrod]

17 hours ago, wornish said:

Also I have read that you can't use electronic focusers on the HD tubes because of the mirror lock screws, is that true?

 

 

Are you thinking of the issue with the Celestron electronic focuser? It wouldn't fit on an EdgeHD 9.25" until they had produced an adapter. The Celestron focuser mounts over the existing focus control knob on the OTA.

[Grierson]

On 10/05/2020 at 18:44, Craney said:

In answer to your last point.....  surely such an Astro-giant as Celestron would not make such a clanger....

Maybe for certain brands.... but I've seen pictures of Moonlites that are on the back of Edge optics.

Could I just briefly side track the thread to ask a naive question? Why would you add a Moonlight or other focuser to the Edge? Is the native focuser that bad? Thanks - John

[Craney]

5 minutes ago, Grierson said:

 Is the native focuser that bad? 

I use it at the moment because I don't have an option to do otherwise.   It's not terrible.  

I do find it a wee bit vague when it comes to fine focus . Locking the mirror after establishing the exact position tends to shift it a bit.   #never_ending_task !!

Saying that,  I have had all night imaging sessions at all altitudes and azimuths and the focus has kept true once fixed.

Having an electronic  motor focus system  that clips onto the knurled knob of an add-on focuser , that can serve the SCT  as well as your refractor and newtonian  is also an incentive.

[Grierson]

Thanks Craney, I have just received the Edge HD 8" but I have not had chance to point it at anything yet! I am still trying to sort out the back focus spacing and the guiding configuration. I had seen a number of similar images of additional focusers having been added to the Edge and I just wondered why. I'm hoping to replace the native focus control with a Feather Touch as I have the ZWO focus controller which I use with the ASIAIR and for which ZWO provide an adapter for the Feather Touch.   

Apologies to wornish  once again for hijacking the thread, 

[ollypenrice]

16 hours ago, Grierson said:

Could I just briefly side track the thread to ask a naive question? Why would you add a Moonlight or other focuser to the Edge? Is the native focuser that bad? Thanks - John

You can fine focus with the Crayford while leaving the mirror locked.  

Olly

[gorann]

I found that one of these works fine for focusing my Meade 14" ACF after I have locked the mirror.

https://www.teleskop-express.de/shop/product_info.php/info/p7106_TS-Optics-2--UNC-V-Power-Crayford-Focuser-for-2--and-3--SC-Thread.html

I may also add one to my EdgeHD 11" but so far fine adjusting the focus with a JMI motorfocus on the mirror has worked rather well.

[Grierson]

Thanks chaps, obvious once you have been told! Do you ever stop learning about this hobby! I must resist any further expenditure at the moment Goran or divorce will be on the cards  🙂.

[gorann]

1 minute ago, Grierson said:

Thanks chaps, obvious once you have been told! Do you ever stop learning about this hobby! I must resist any further expenditure at the moment Goran or divorce will be on the cards  🙂.

Just say that it has always been there, you just have't noticed it darlig😎

[Grierson]

1 hour ago, gorann said:

Just say that it has always been there, you just have't noticed it darlig😎

😀 😀

[Obi Wan Ken00bi]

Maybe slightly off-topic, but can you use an Edge HD 9.25 in a fully remotely controlled observatory? Do you need to collimate/ mirror lock (whatever that means) every time you image or only every now and then? 

[wornish]

Blimey my thread has developed a whole life of its own.  Some interesting feedback thanks.  At these long focal lengths I think Lunar and Planetary imaging is fine but don't think my seeing and  mount tracking are up to long exposure imaging of DSO.  The pixel scale is too small.  Anyone using an ASI1600 MM Pro on an edge HD care to share an image or comment.

Edited May 16, 2020 by wornish