How big can I print these?

Would 16 by 20 work? Https://flic.kr/p/CbMDi8 https://flic.kr/p/CsU2Nc taken in nikon d3300 first one has high thermal noise because it's a 13 minute exposure

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Will I be able to use a Canon EF 70-200mm f/2.8L IS USM II Lens on a Nikon d5000?

Friend has a canon camera and I used her lens on my nikon and it worked but this one is bigger.

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