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- Name
- Chris
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I have a couple of old lenses for my old Pentax, a 28mm and a 200mm telephoto that I have tried on my Nikon D3100 via a lens converter.
I decided to try them out because my kit lens has a maximum aperture of F5.6 whereas the 200mm has F3.5 and the 28mm F1.8.
Can you tell me what the actual focal length of these lenses will be as I understand that full format and DX cameras give different results with the same lens for example? I have seen a new 28mm for a full format camera that states it will be 42mm with a Dx.
I decided to try them out because my kit lens has a maximum aperture of F5.6 whereas the 200mm has F3.5 and the 28mm F1.8.
Can you tell me what the actual focal length of these lenses will be as I understand that full format and DX cameras give different results with the same lens for example? I have seen a new 28mm for a full format camera that states it will be 42mm with a Dx.