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  1. #1
    HeXploiT's Avatar
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    Default What's the widest field of view eyepiece for my Celestron c8



    I'd like to spend <$100 on the widest view(lowest power) eyepiece possible for my Celestron C8. There's more to this than the math as there are so many different brands available and I'm not familiar with them all and the quality of each.

    Also the C8 uses 1.25" eyepieces but would I be able to get an even wider field if I use a 2" adapter & eyepiece?
    I want to see how much sky the C8 can squeeze into one eyepiece.
    Any help appreciated.
    {Celestron C-8 + CG-5 Pro}
    {Meade ETX-90 + Old C8 Aluminum Mount}
    {Celestron SkyMaster 15x70}

  2. #2
    WWPierre's Avatar
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    Default

    Don't know about the 2" thing, but the governing factor is the exit pupil. In theory your scope could take a 60mm eyepiece. Haven't seen any, but I just won a 40mm plossl on EBay for less than $30 shipped to my PO box.
    Meade 16" LightBridge; Celestron G-8N Bird-Jones/motorized EQ5;
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  3. #3
    HeXploiT's Avatar
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    Default

    I've been wondering about those eyepieces for awhile now. I think the brand name is garret?
    Something like that. There are many of them on ebay and they're very inexpensive. Only reason I haven't purchased one is because at that price I was afraid they might be very low quality.
    After you get this let me know what you think of the quality/performance.
    You ought to start a thread and do a review.
    {Celestron C-8 + CG-5 Pro}
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  4. #4
    WWPierre's Avatar
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    Default

    I'm looking at that big piece of glass. I plan on using it on the Mak. I know it won't work on the dob because a 35mm wouldn't. I will be comparing it to my 30mm Siebert.
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    49-41-37.03N 123-09-29.61W Calculated magnetic declination: 17° 39' East

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  5. #5
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    Default

    The issue with Cats in general is that the light cone is reduced by the baffle inside. So, without vignetting, it is going to depend on the diameter of the actual hole in the back of the mirror. The widest TFOV = arctan( 48mm / fl ), where 48mm is the inside diameter of a 2" EP. In general, a C8 has at most TFOV 1.37 degrees, assuming the baffle is not narrower. I believe however it is.

    I just ordered a 40mm AT Titan II for my scope. Hopefully give you an update on its performance.

  6. #6
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    I think a focal reducer would help you. It works sort of like a reverse barlow. It will cut your f# down and give you a wider field of view with your current eps. Here is a link to one. Cheers.
    name: Derek

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    and such.

 

 

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