Will this lens fit my camera? - 2

I'm interested in purchasing a PENTACON 50mm F1.8 M42 lens. I'm also buying a Nikon D3100 but I'm new to DSLR cameras. What mount do I need to buy to fit this lens on the camera?

The Pentacon 50mm f1.8 M42 lens is a screw-mount so you'll need an M42 to Nikon mount adapter.

You will have no communication between the camera and lens so be prepared to manually focus the lens and to use stop-down metering.

In my opinion you'd be smart to save your money until you can afford the Nikon AF-S 50mm f1, 4 prime lens. Never forget that the Nikon D3100 requires Nikon's AF-I or AF-S lenses if you want auto focus.

Generally to get all the features of a camera to work, you have to buy the lens made by the maker of the camera

In this case, ANY Nikkor AF-S lens will work perfectly with your fine new D3100.

The old, old M42 mount lenses were made to fit the old Pentax screw mount Spotmatics (last made in 1975) and other M42 compliant cameras of the era.

Due to the flange mount differences between the old M42 lenses and Nikon bodies, an adaptor with an optical element had be used to retain the original focus range of the lens, at the expense of some image quality. Finding one you can use with a modern Nikon body will be the real challenge.

http://www.rugift.com/photocameras/nikon_lens_adapter_with_lens.htm

Edwin is right on the mark with his answer, If money is an issue either look for a used DX lens in good shape or consider a Nikon G series lens. The G-series will work just fine with any Nikon, the only thing is that there's no ring to set the aparature. One of the best things about the digital age is that people get rid of cameras left and right. The prosumer Nikon market is flooded with great used cameras while the D-2 and D-3 users tend to hang onto their cameras for years.

You need a Nikon to 42mm adapter but don't be surprised if the Pentacon lens won't focus on infinity. Nikon is not the best camera to use these old lenses as it's camera mount flange to sensor distance the the largest of any camera manufacturer.

This distance is hyper critical (fractions of a mm count). Some of these old lens could focus past infinity to allow for discrepancies in the lens not always being fitted properly (that and the introduction of Auto Focus was the reason for introducing bayonet fittings), some can't. Pentax and Canon don't have this problem.

The best camera to buy for using old lenses is undoubtedly the micro 4/3 mount of the Panasonic G1 or G2, their tiny 20mm mount to sensor distance allows most any lens to be used, such as old Leica such as the Summilux.

Even lenses designed for TV and Cine cameras can be used with such gems as an Angenieux 200mm f1.8, these lenses were used in the film industry and cost tens of thousands of dollars when new, they all offer exceptional image quality, now available for a few hundred dollars. This company is still around and as their lenses were (and are) guaranteed for life you can still return any damaged ones to Switzerland where they were made and have them repaired for just the carriage costs. We're talking probably the best lenses money can buy here.