I regularly use teleconverters. Sometimes I don’t want to lug a long telephoto lens on a trip, and other times I see an unexpected shot and want a longer lens. Of course we know that using teleconverters has some drawbacks. You lose 1-2 stops of light depending on which converter you use, and image quality will start to suffer. Zoom lenses typically don’t produce as good of results as prime telephotos, although I have had great results using my 1.4x converter with my 70-200mm lens. But how good would the results be using teleconverters on one of the sharpest lenses Nikon makes, the 200mm F2? I decided to find out.
I always base my lens reviews on real world results. I’m only interested in ‘is this image sharp’, and could it stand up to large reproduction…i.e. large home prints or trade show displays. Image sharpness and file size determine the end result. I’ll enlarge the native files to 100 percent on my computer and take a close look at the corners. This simple test will tell me what I need to know. To test my 200mm F2 I went to a nearby park, found a stationary ‘frog’, and starting shooting.
First shot, the frog with the 200mm, no converter. So sharp you could cut paper with it.
Next, the frog with the 200mm and 1.4x converter. Still excellent, I would not hesitate to use this anywhere. The bar is so high starting with the 200mm that sharpness is still remarkable. But at 200mm with 1.4x you are only getting a 280mm, not that much of a telephoto.
Here is the ‘frog’ photographed using the 200mm with 1.7x converter resulting in 340mm. I begin to see just a little image quality loss on the edges, but the center is still very sharp.
Finally, here is the shot using the 200mm and the 2x converter, so a 400mm F4 equivalent. Autofocus still worked fast and accurate. With this image edges have lost some clarity, but still decent sharpness in the center. I would have no worries using the 2x with this lens and still getting good sharpness. The bottom line is this lens works great with all three converters, and expectedly loses sharpness as you go from 1.4x to 2x. The 1.4x and 1.7x produced excellent results.
An interesting question, and topic for a future blog post is this; do you get better results using a 2x converter, or enlarging a native file using interpolation software? And on the same note, why not just crop down a D850 or Z7 file (45MP) 50 percent using the native 200mm lens so you end up with a 22MP file that has a 400mm angle of view? Just how big of file do you need? And what about rumors the next Nikon mirrorless camera will have a 60MP sensor..can you image how much you can crop this for tighter shots and still have a large file? Wow, lots of good topics to discuss in the future!