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It should be noted that these old clasic big refractors are all constructed at the optimal f15 focal length. I think this is where the difference between modern refractors and newtonians becomes muddled, most are made to be less cumbersome by reducing tube length and therefore f ratio. 30 years ago long tube f15 refractors were the norm, and 8", 10" and 12" newtonians were standard at f6 and f7. You have to get scopes with these longer focal lengths custom made these days.
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