50mm x 1 1/4"

I have a Celestron C90 MAK and it came with 32mm eyepc, I am looking for 22 to 25 power and with a 1200mm focal lenght It looks like I need a 50MM x 1 1/4 and they are not easy to come by. would this be practical If I found a 50mm eyepc. would the clarity be there, or should I just get a spotting scope where 25 power is readily easier to get.

Chet

Hi Chet,

The 50mm in a 1.25 barrel is not used because it does not provide a pleasant view. The 1.25 barrel restricts the field of view so much that the view is like looking down a tunnel (some say like looking through a soda straw!) Even a 40mm will suffer from this. Also, in daytime use you would probably see the shadow of the secondary.

IMHO, you would prefer a spotting scope.

regards,
dan

Hi Chet,
As Dan has indicated the main problems with a longer Focal Length EP I won't repeat his observations. I can tell you that a 45mm Silver Top, 1 1/4" and a 40mm SW Konig, 1 1/4" suffer the same malady in a MCT of this aperture. The first decent Focal Length that doesn’t give you Tunnel Vision and have a gray spot with the 90mm MCT I tried was a 35mm Clave 1 ¼” (which has a narrow FOV) and a 32mm UO Konig 1 ¼”.
A 36mm ‘Super Wide Plossl’ I tried showed very minor signs of a dark center although teh "Tunneling" wasn't objectionable.
My guess it that you could get away with a 40mm Ortho with minor issues but a 40mm Plossl might cause problems.
I’d go for the Spotting Scope or a small refractor. I just picked up a Meade 277, 80mm Refractor (Object by Vixen in those days) with Table tripod, diagonal, case, etc. for about $85.00 shipped. With a TeleVue 1 ¼” diagonal and TV eyepieces it’ll match any achromatic out there and is Much better than my $300+ Leopold shooting scope.
Cheers, Bill

I have a Celestron C90 MAK and it came with 32mm eyepc, I am looking for 22 to 25 power and with a 1200mm focal lenght It looks like I need a 50MM x 1 1/4 and they are not easy to come by. would this be practical If I found a 50mm eyepc. would the clarity be there, or should I just get a spotting scope where 25 power is readily easier to get.

Chet
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If you want 22 to 25 X, a refractor is going to be your best bet. They sell MAKs a spotters but the long focal lengths restrict the field of view so that 24X with a 50mm eyepiece will have the same true field of view as your 32mm at 38X.

A 80mmF6 refractor with a 2 inch focuser can provide some amazing widefield views at 15-20X.

Jon

Hi Chet,Did you ever get a higher power eyepiece for you C90 for 300 yd. target shooting?
>>>>>Steve