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Astro Adapter for 883 (1 Viewer)

KBHC73

Well-known member
England
Hi, My set up inc 883 with 25-60x fixed 35x & 1.6x extender. Which Astro adapter would be best as i recently saw there are 2 to fit the scope? Also which Astro eyepiece would give the best results as i don't want to overpower the scope.

Thanks
 
Hi, My set up inc 883 with 25-60x fixed 35x & 1.6x extender. Which Astro adapter would be best as i recently saw there are 2 to fit the scope? Also which Astro eyepiece would give the best results as i don't want to overpower the scope.

Thanks
Use the Kowa AS1.25G 1.25" grub screw one. The one with the knurled screws doesn't allow infinity focus with some eyepieces.

I have used Morpheus 12.5mm, APM HI-FW 12.5mm and APM XWA 3.5mm with my 883 and they all reach focus to infinity with the grub screw adapter and won't vignet.

Regards, Juhani
 
Use the Kowa AS1.25G 1.25" grub screw one. The one with the knurled screws doesn't allow infinity focus with some eyepieces.

I have used Morpheus 12.5mm, APM HI-FW 12.5mm and APM XWA 3.5mm with my 883 and they all reach focus to infinity with the grub screw adapter and won't vignet.

Regards, Juhani
Thanks ; )
 
Use the Kowa AS1.25G 1.25" grub screw one. The one with the knurled screws doesn't allow infinity focus with some eyepieces.

I have used Morpheus 12.5mm, APM HI-FW 12.5mm and APM XWA 3.5mm with my 883 and they all reach focus to infinity with the grub screw adapter and won't vignet.

Regards, Juhani
Well, yes and no.
If you need the extra 5 mm of in-focus to get to infinity focus then the grub screw adapter is mandatory.
However, you will need one for every eyepiece and changing eyepieces is a slow process with the long fine thread.
With the external screw adapter you can use a low power eyepiece (I have a 28 mm RKE) as a finder and then drop in a short focal length, e.g. 3,5 mm Nagler, for high power views.
By the time you had changed eyepieces with the grub screw adapter the moon or planet would be outside the field of view and finding it again with a mere 0,5° TFoV would be very frustrating.

Regards,
John
 
Well, yes and no.
If you need the extra 5 mm of in-focus to get to infinity focus then the grub screw adapter is mandatory.
However, you will need one for every eyepiece and changing eyepieces is a slow process with the long fine thread.
With the external screw adapter you can use a low power eyepiece (I have a 28 mm RKE) as a finder and then drop in a short focal length, e.g. 3,5 mm Nagler, for high power views.
By the time you had changed eyepieces with the grub screw adapter the moon or planet would be outside the field of view and finding it again with a mere 0,5° TFoV would be very frustrating.
Agreed; if you use several different eyepieces and switch them often (and are sure that they can reach focus to infinity) the knurled screw adapter is more convenient. APM 12.5mm can't reach focus to infinity with the knurled screw adapter, if I recall Morpheus 12.5mm did but by just, with APM 3.5mm I haven't tried the knurled screw adapter.

I bought two crub screw adapters (after all, they are not terribly expensive) as I have used only 12.5mm and 3.5mm eyepieces (and the 25-60x zoom + 1.6x extender) so they are fixed into both 1.25" eyepieces as I have (yet...) no other scope to use them with. I also have no problem finding planets even with 3.5mm as the cable tie sight works great in astronomy also (but it would surely be great to scan the night sky with 28mm eyepiece in 883 anyway!).

Regards, Juhani
 
I also have no problem finding planets even with 3.5mm as the cable tie sight works great in astronomy also (but it would surely be great to scan the night sky with 28mm eyepiece in 883 anyway!).
With a solar filter I have problems finding the sun with a 2,2° FoV (16x the solid angle?) and I can't use a cable tie on the sun! :(
The 28 mm RKE only has about 45° AFoV - a WA 1.25" eyepiece in this focal length is an impossibility - but terrestrially it's quite spectacular in its own way at 18x with a 5 mm exit pupil on the 883 and 21 mm eye relief.

Regards,
John
 

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