Will this bag hold a Nikon D90 + 1.7...
Will this bag hold a Nikon D90 + 1.7 teleconverter + 300mm Lens?
What is the sizes of the 300mm?
In the market you can fined large 300mm like the : Telephoto AF-S Nikkor 300mm f/4D ED-IF...in that case the lens is to big
Or: 70-300mm f/4-5.6 DG Macro...in that case yes
You need to check the size of the body an add to it the size of the less + 1" for the safe side