OAG to 8x31 EFW

Tech@ZWO

SantiagoNucete Which version of OAG and camera do you have?
If you have the standard OAG, no need to drill holes in the plates. here is a 55mm connection way for your reference.

w7ay

Tech@ZWO here is a 55mm connection way for your reference.

How do you orient the prism stem above the long axis of the camera sensor with the scheme that you showed in the screen shot?

Chen

SantiagoNucete

Tech@ZWO Could it be that the combo I bought has the wrong plate on the EFW? Since the camera came with is compatible but not the OAG that was included.
Thank you!!

Tech@ZWO

w7ay Add the spacer and adjust it via the three-jaw adapter.

SantiagoNucete

I bought a 1600 MM pro and my OAG is the large Off axis Guider with 12*12 prism. The only way i see to connect mi OAG to my filter wheel is through these screws I mentioned previously.

I cannot resort to a dealer as I bought directly from ZWO, had it shipped to the US and then brought by a friend from the US to Argentina, where we have no way of importing things without delays, overpriced tariffs or other hustles...

Is there any plate sold separately that I may aquire and have sent to me as I did with the rest of the equipment?

Tech@ZWO

SantiagoNucete Hi Sounds you purchased is OAG-L, not OAG.
In this case, this way is not suitable, because OAG-L can only be fixed with screws.
If you don't have a back focus requirement, you can connect them via other adapters, such as a T2 tilter or 15mm adapter.
Or drilling the back plate of EFW to connect OAG-L, but you need to keep the distance from the camera sensor to OAG more than 32.5mm, otherwise, the main camera and guide camera can't focus at the same time.

w7ay

Tech@ZWO Add the spacer and adjust it via the three-jaw adapter.

With 0.75mm pitch M42 thread, you need very thin spaces to get enough angular resolution to get the correct angle dialed in.

My question again: how do you orient the prism to exactly be at the long axis of the sensor?

Chen

Tech@ZWO

w7ay Adjust the direction via this adapter and spacers(if needed).

w7ay

Tech@ZWO Adjust the direction via this adapter and spacers(if needed).

Yes, but what about this solution that you gave him?

"If you don't have a back focus requirement, you can connect them via other adapters, such as a T2 tilter or 15mm adapter. "

How does he align the prism orintation with that?

Chen

Tech@ZWO

w7ay He said the prism on his OAG is 12*12mm, so it should be OAG-L, not the standard OAG,
so can only use the spacer

jaaph

w7ay you can align by adding a very thin spacer between the camera and the EFW. 0,1 mm will already give you an 36 degree angel ( 1mm is 360 degrees so 0,1 mm is 36 degrees angel change)

w7ay

jaaph 0,1 mm will already give you an 36 degree angel

And that (36º) is not very good.

By the way, the ZWO T2 thread has 0.75mm pitch. M42x1 flanges with 1 mm pitch are the ones used in the very old M42 camera lenses.

https://en.wikipedia.org/wiki/T-mount
vs
https://en.wikipedia.org/wiki/M42_lens_mount

Chen