Why Would I Need a Teleconverter?

I recently purchased a teleconverter for which I have been saving up. I plan to undertake a photography expedition in spring that will involve landscapes and potentially a lot of wildlife and I have been trying to up my wildlife game in preparation. Shooting wildlife photos is quite a different skillset and equipment set compared to landscape photography and I have mainly focused on the landscapes up until this time.

With a landscape you will go shoot something that doesn’t move, though the light does change. I would ordinarily use wide focal lengths up to lower telephotos (from 14mm – 200mm), let the aperture inform the shutter speed, set at base ISO for best image quality, focus once, and shoot photos. Wildlife photography is much the opposite as you will probably want to shoot well over 200mm focal length, with the shutter speed dictating the rest of the camera settings, use higher ISO for fast shutter speed, and you will rely heavily on the camera’s continuous auto-focus abilities.

The longer focal length is where the teleconverter comes in. A teleconverter is an adapter that you install between the lens and camera that increases the focal length. But, this comes with the trade-off of reduced aperture and slightly poorer image quality (I’m told). Below is a photo of the Nikon 2.0x teleconverter that I purchased. 2.0x means that it will double the focal length of the lens you are using. There are a variety of third-party teleconverters available, but I have read that they do not work nearly as well as one that has been designed to work with your lens. So, I went for this to get the best results.

This teleconverter is currently only specified to work with four Nikon lenses, including the Nikon Nikkor 100-400 f/4.5-5.6 VR S, which I also have. With this combination I should have the ability to shoot from 100mm all the way out to 800mm and this should make for a pretty good wildlife shooting rig. But, if you really want to spend money, Nikon will be happy to sell you an 800mm f/6.3 prime lens for $6500 or a 600mm f/4 with built-in teleconverter (840mm) for $15,500.

Nikon Nikkor 100-400 f/4.5-5.6 VR S Zoom Lens and TC-2.0x Teleconverter

As I pointed out above, you lose quite a bit of aperture when you mount this teleconverter. The 100-400 f/4.5-5.6 VR, which is not an especially fast lens, becomes a 200-800 f/9-11 VR with the teleconverter attached. That is a difference of 2 stops of aperture or a quarter of the available light! To compensate for this loss of light without sacrificing shutter speed, you have to add 2 stops of ISO!

The ISO setting is basically how much gain you have to apply to the signal from the sensor to get a good image. When there is plenty of light and you can shoot at base ISO, the signal from the image is much, much larger than the noise so the image is nice, sharp and clean. But, when there is less light projected on your sensor, either because of darker conditions or a darker lens, the signal is much smaller and to get a good image you have to increase the ISO to amplify the signal, and when you amplify the signal you also amplify the noise. So the higher the ISO you have to use to get a useable photo, the more noise will show up in the image, and this noise can also affect the sharpness and color of your image. So, the teleconverter doesn’t give you all that reach for free as you may pay for it in image quality without good light. All that said, on a modern digital camera you should be able to shoot and get good images well into the quadruple-digit ISO settings. I would really start worrying above 10,000 though.

So, with my shiny new teleconverter I went to practice at a pond with some waterfowl on a sunny afternoon. Another technique I need to get good at for wildlife photography is focusing. For a landscape photo, I would set the camera to pin-point, single-servo auto-focus as my subject does not move. But for wildlife, both the subject and the camera are frequently moving so I have to get used to wide-area, continuous-servo, auto-focus and rely on the camera to track the animal. Cameras are pretty good at detecting animal eyes and focusing on them, which is nice, but you do have to position yourself so that the animal gets good light, wait until the animal decides to do something you want to photograph, and shoot when the focus box is on its head. It does take a bit of practice.

The other thing I have to get used to doing is shooting with a really fast shutter and letting the ISO go into the quadruple digits, which can be really disconcerting to a landscape guy that ordinarily shoots at base ISO (64). Shooting a moving object with a moving camera at a long focal length requires a really fast shutter even with all the vibration reduction built-in to the lens and camera. Below is an Egyptian goose shot at 800mm focal length, 1/800 second shutter speed, f/11, and ISO1100.

Nikon Z7II, Nikkor 100-400 f/4.5-5.6 VR, 2.0x teleconverter; 800mm, f/11, 1/800 sec, ISO1100

This goose stood still in some sunlight for me for a few seconds as I got him focused in for a shot and I was able to hold still and shoot, so it is pretty sharp at 1/800s. The rule of thumb for shutter speed when hand-holding is generally 1 over the focal length, which is 1/800 second in this case, but all the vibration reduction does buy you a couple of stops according to the literature so I theoretically could have shot down at 1/200 second. The auto-focus had no trouble identifying the goose and getting a sharp focus and I had bright sunlight to keep the ISO in the low thousands (eek!). To help keep the auto-focus from getting lost on nearby items, there is a switch on the lens that limits its focus range to 3 meters to infinity and this is quite helpful. I am not sure if this range in modified by the teleconverter.

I was actually sitting on a bench quite distant from the geese as they didn’t like for me to get too close, and even from this distance I couldn’t keep the entire goose in the frame at 800mm. For comparison, below is one of the geese shot at 430mm, f/10. He was actually walking along the grass so I had to bump up the shutter speed to 1/2000 sec. 430mm is just a little more than I would be able to get without the teleconverter attached.

Nikon Z7II, Nikkor 100-400 f/4.5-5.6 VR, 2.0x teleconverter; 800mm, f/10, 1/2000 sec, ISO1250

I took off the teleconverter and shot with the lens-only for comparison of image quality. Using just the lens, you can shoot at a much brighter aperture and drop the ISO back down, reducing noise. The below photo is hand-held from a standing position near the pond and shot at 400mm. I was able to shoot with a faster shutter and lower ISO without the teleconverter.

Nikon Z7II, Nikkor 100-400 f/4.5-5.6 VR, 400mm, f/5.6, 1/2500 sec, ISO500

Shooting in such an abundance of sunlight, I really didn’t see a huge difference in sharpness or color detail between the images during editing. The autofocus was faster without the teleconverter, but only a little bit faster. I am confident that I will be able to get good wildlife images using the teleconverter if I can work the camera correctly.

My camera has 3 user configurable settings on the main dial, so you can turn on the camera in U1, U2, or U3 and have it come up in a known state. I use U1 for landscape and have it set to aperture priority, f/6.3, ISO64, pin-point, single-servo auto-focus, with a single-exposure, and this is a good starting place for shooting landscapes for me. I am working on configuring U2 for wildlife and this will probably be shutter priority, auto-ISO, wide-area animal auto-focus with continuous servo, and high-speed continuous shooting. But, I have a lot of practicing to get in to be ready for serious wildlife shooting. U3 is set for people portraits.

As to the geese, these were Egyptian geese which are native to Africa. I guess they were brought to North America for some reason and eventually got loose and went wild. I have read that there is also a population of them in the UK. Their feathers do have a pattern that makes them appear to be textured. When I looked at the photos after I edited them, I assumed that I had over-sharpened them, but that is what they look like. They seemed to hang out in pairs, with the male jealously guarding his female getting irate and honky when other geese approached.

Nikon Z7II, Nikkor 100-400 f/4.5-5.6 VR, 2.0x teleconverter; 800mm, f/13, 1/1250 sec, ISO1250

Well, that’s my first shot at using a teleconverter. I look forward to shooting some wildlife with it this year and sharing those photos with you here. Thanks for reading.

10 thoughts on “Why Would I Need a Teleconverter?

  1. Beautiful shots. Looks like you’re goosing up your photography skills in 2023. I’ve heard that wildlife photography requires many of the same skills used by hunters. Be careful applying the deer scent, as you may find yourself mistaken for a doe by a large antlered buck.

    Liked by 1 person

  2. Well at least I found your post before the end of the day! Though now I need more ice due to the comments.
    Egyptian geese, that explains why they look different. I like them, you did a great job.
    I am really glad you know how to use the fancy cameras and all the fun toys that go with them, so that we can enjoy your wonderful photos. πŸ™‚

    Liked by 1 person

  3. The hardest issue for landscape and portrait photographers to deal with is ISO. I’ve gone out with many pro portrait people and they fight, and lose, the ISO battle all day. In panning a single animal on the move you can go from deep shadow to sunlight glare, in 4 clicks πŸ˜‚.

    Eventually we all learn to deal with ISO in post. Either that or inflight, on the run, and other movement will drive you crazy with misses. πŸ˜‚πŸ˜‚.

    I look forward to seeing your work.

    Liked by 1 person

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