As we all know, camera lenses can be incredibly expensive so if you have more than one camera system, e.g. Sony, Nikon, Canon, Panasonic etc then you often forced to lay out a lot of money to have the latest and greatest. Of course there is always the option of buying second hand lenses, for example through Wex and other main dealers, as well as through Ebay and Amazon. There is however another option. A cheap and practical way of overcoming the issue of lens incompatability between systems is to consider using a lens adapter. For example, you could mount your expensive Nikon lenses to say Fuji, Olympus or Panasonic camera bodies simply by using a lens adapter. These adapters come in many forms, some providing full auto-focus and aperture control between the different camera / lens types, others only providing manual focus and aperture control. With this difference in function comes the obvious difference in price and unsurprisingly, fully automatic adapters are generally much more expensive than those that provide only manual functionality. C'est la vie!
Being a relative cheap-skate, and having some old legacy glass from my Pentax film days, buying and owning a Panasonic GX-80 and a Nikon D600 means that I have a multitude of lenses sitting around which fit only the systems they were designed for. Well, at least in theory because I also own a couple of inexpensive lens adapters which allow me to use my old legacy glass and my newer Nikkor / Tamron lenses, on my Lumix GX-80. Personally, I haven't gone overboard on these devices as I am more than happy to fly manual in my photography and to be honest, I'll flip to manual even when the lens is capable of fast auto-focus.
Having had a Pentax KM to Micro Four Thirds (MFT / M43) adapter for some time, I was keen to see whether I could get the same brilliant performance from a Nikon FX to MFT adapter. This would then allow me to use every lens I own, on my lightweight walkabout Lumix GX-80. Here's an example of the performance of an old Vivitar 35 - 70mm (f2.8 - 3.8) with a Pentax KM fitting when attached via an inexpensive Beschoi PK-MFT adapter. Not a bad result for a lens costing under £30. One thing to remember though is that when using lenses designed for a particular sensor size, for example 35mm film cameras, is that when used on non 35mm camera bodies such as an Micro Four Thirds system, there is a crop factor to apply. Because the Lumix GX-80, has a micro four thirds sensor, any lens designed for use with 35mm sensors / cameras will give me a 2x crop factor, effectively a doubling of its focal length. So, for the old Vivitar above, the new focal length becomes 70 - 140mm. Also, because you are making it a little harder for the light to reach the sensor, the aperture of the lens won't be quite as efficient so you may have to increase exposure by a few EV to even things out. Overall though, a simple adapter should have no real effect on aperture value so using vintage pro glass now becomes of significant interest.
As an example of what a 200mm Pentax lens can achieve on the Lumix GX-80 with an adapter (this now becomes 400mm) take a look at this photo from the recent airshow at Paignton, Devon. Not perfect of course, but not bad for a hand held shot at max focal length and manually focused. Best of all, this lens cost just £5 on Ebay and while I am not saying don't spend big bucks on quality lenses, what I am saying is that your old legacy glass still has a role to play in your current photography.
As mentioned above, one of the Nikon lenses I own is a Tamron 28-300 AF Aspherical XR Di LR If lens which although not the best ever, is a great walkabout lens with a decent focal length. When coupled to the Lumix GX-80 via the KAF Concept Nikon G - MFT lens adapter, this focal length becomes 56 - 600mm in basically the same package size as the Nikon D600 when fitted with this lens. These next couple of images is this lens at maximum range (f=600mm) and f8 with an effective distance of around 300m from camera to subjects. Without doubt this is stretching the lens to its limits and this can be seen in the results.
So, a good quality lens adapter can handle long distance shots with relative ease. What about closer in, does an adapter create problems at lower focal lengths. The answer is no, not really. In this next couple of images, the subjects are no more than 30 - 50m from the camera and again, the results are pretty good for inexpensive glass.
With the relative cost of a manual lens adapter being around the £20 mark, these offer photographers the opportunity to use lenses from other brands on their newer cameras. The KAF I used with the Tamron was £18 from Amazon. It allows me to use any Nikon lens with an F fitting, even Gelded (G) lenses that don't have an aperture ring, on my Lumix GX-80. You can see the control for this in the photo below, the silver knurled ring provides aperture control for Nikon G type lenses. Since practically every lens ever made by Nikon has an F coupling there is a startling range of legacy glass available. For example, athough I have yet to try it, I have a 50mm f1.4 G Nikkor which would be great for portraiture when fitted to the Lumix GX-80. A similar lens for the MFT system would cost towards £300 with the only disadvantage being I have to work in manual mode. Since I spend most of my time in this mode, and with manual focusing I personally don't see this as a big issue.
As I was writing this, an old Vivitar (Kiron made) 75-205 f3.8 arrived so I shot a couple of quick photos with it fitted to the Lumix GX-80 using the Beschoi PK-MFT adapter mentioned earlier. Other than the fact it weighs a ton, the fact that it is wide open at all focal lengths bodes well for future shooting opportunities.
In general terms, camera lens adapters offer a low cost alternative to buying expensive new lenses when and if you change your camera system. Performance is excellent, with little degredation in image quality plus, if your camera has a smaller sensor than the one designed for the lens, you will see a benefit in terms of extra focal length. For the Micro Four Thirds camera systems, this is a 2x crop factor meaning that a lens with an original focal length of 200mm on a 35mm camera becomes 400mm on the MFT system. With this increase in effective focal length comes a reduction in light reaching the sensor but this can be easily adjusted for in normal usage by opening up the aperture or compensating using EV. Finally, with prices for manual lens adapters being around £20, the opportunity to purchase high quality legacy glass from a host of manufactures means that you can own the very best lenses, albeit in manual mode, for just a few pounds. Of course, should you prefer to retain automatic control of focus and aperture there are more expensive options available, for example Metabones systems, which will provide you with those functions.