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Re: [ATM] barlow focal length


Saqib,
>> Focal length varies - "shorty" Barlows have shorter
>> f.l. If you have a
>> Barlow lens and want to find out its f.l, this
>> webpage may help:
>> http://web.telia.com/~u41105032/barlow/Barlext.htm
>>
>> Nils Olof
>
> i dont have a barlow lens.due to non-availability of
> short focal length eyepieces. i have asked an optician
> to make one for me.so thats why i need exact focal
> length.

There is no exact focal length. Somewhere like 100 mm is fine for a 2x 
Barlow. With 2x, the total barrel will be a little more than one focal 
length, and the extension outside, where the EP will sit, is about 1/2 focal 
length.

N O 


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