Where to buy a Lens Adapter 

I purchased my adapter off eBay. In fact I'm going to recommend the seller that I used. He was very quick and polite in responding, and shipping was a very fair price.  I will be ordering adapters from him in the future, and feel comfortable recommending him to my readers!  Take a look at Treasuresale's eBay Store. 

Tips to keep in mind

1. Some of these old lenses like the Nikon I used in this example don't have the exotic multi-coatings we might be used to on modern lenses. So I would highly recommend a high quality filter to improve contrast and keep out glare.
2. It's a lot easier and not that much more expensive to purchase multiple adapters for your lenses. By leaving an adapter on each lens it is ready for use and you can swap them on and off your camera just as any regular lens.
3. It's usually a lot easier to mount the adapter on the lens before mounting it on your camera. You won't have this problem if you follow tip #2 anyways.
   

My Results with a Nikon 135mm F3.5 prime

Here are a few sample shots I did with a pristine condition Nikon 135mm F3.5 Prime my dad found.  It is a beautiful lens to work with and I enjoy having such a high quality lens on my camera for such little cost. 

This sht was taken with the Nikon 135mm on my Canon EOS body. As you can see the results are excellent, especially considering this lens can be found under $100 CDN. You can easily see me and my bathroom in the reflection

In the 100% crop the text detail is very fine, this might be even better than my Canon 50mm 1.8,. The build quality of the lens sure is better though.

The results are excellent.  The old Nikon lens is a great performer.