Last updated on December 5th, 2023
Ever wondered, “what is a teleconverter?” Have you ever been on location and wish you could get a tighter shot, closer up? Were you just out of range of the perfect framing you were looking for? That is when a teleconverter comes in handy.
Let’s explore what is a teleconverter and go over if a teleconverter is right for you. We’ll boil down some of the positives and negatives about using a teleconverter so you can make a worthwhile decision in the end. Let’s explore:
What is a Teleconverter?
A teleconverter, which is also commonly known as an “extender” or “multiplier” is a secondary magnifying lens. A teleconverter attaches between the camera body and the lens. The teleconverter’s purpose is to increase the focal length of the lens you are using so you don’t have to get any closer to your subject physically. Many wildlife photographers use teleconverters, so the telephoto reaches their subjects. Wildlife photography isn’t the only reason to use a teleconverter, though. You may need one to reach with your landscape photography at some point. Either way, a teleconverter is excellent to have in a photographer’s arsenal for when you have a more considerable focusing distance. You’re able to get high-quality close-up photos of any subject with a teleconverter at the same focus distance.
The magnification effect of a teleconverter varies depending on the teleconverter. The magnification may be a 1.2x, 1.7x teleconverter, 2x converter, or 3x converter. The most common teleconverters are 1.4x converter and 2x converters.
For example, if you attach a 2.0x teleconverter on a 135mm lens, the focal length will become 270mm. Or a 1.4x teleconverter to a 70-200mm lens, the focal length will become 98-280mm. Now, if you attach the 1.4x teleconverter to an APS-C camera with a 70-200mm lens, the focal length becomes 156-448mm.
Not only does a teleconverter affect the focal length but also the aperture. So, if you were to attach a 2.0x teleconverter on an f/2.8 lens, then the effective aperture would become f/5.6. You will nearly be losing two f/stops.
What Does a Teleconverter do?
A teleconverter is made up of multiple optical elements. The total number can vary depending on the optical design and focal length multiplication factor of the teleconverter. The larger the multiplication factor and the longer the teleconverter, the larger the physical size and weight.
Since most teleconverters are designed to be used with several different lenses, their optical design usually incorporates standard lens elements without optical corrections, which unfortunately results in increased optical aberrations, such as lateral chromatic aberration.
In some cases, manufacturers try to minimize optical aberrations’ effect by incorporating more complex lens elements. The elements might include aspherical elements into their teleconverter design.
What You Should Know About Teleconverters
Magnification of Teleconverters
When you use a 1.4x converter, you get a leg-up when it comes to magnification without diminishing image quality. The focal length will be increased with the lens you’re using. So, if you’re using prime lenses or zoom lenses, a 300mm lens turns into a 420mm, a 70-200mm turns into a 98-280mm zoom, a 600mm lens, and so on.
There’s also 2x converters, which you will see named a “doubler” that are popular. This will double the focal length, but the image quality might not be as excellent. If you’re trying to achieve a more resonant focal length, it may make sense to use a zoom lens on manual focus in this case. If you want a more intermediate teleconverter, the Nikon teleconverters are an excellent choice.
Maximum Aperture of Teleconverters
When you use a teleconverter to enlarge an image, the aperture decreases. A 1.4x teleconverter will reduce the maximum aperture by one-stop, a 2x teleconverter will reduce the maximum aperture by two-stops of light.
Let’s say you use a 1.4x teleconverter on a 300mm f/4. Then, it is a 420mm f/5.6. Use a 2x teleconverter with a 70-200mm f/2.8, and it is now a 140-400mm f/5.6. You could theoretically
Teleconverters are best suited for lenses with a wide maximum aperture. However, note that slow shutter speeds and high ISO settings won’t give you the shallow depth of field you’d get with your lens otherwise.
Autofocus Compatibility
Your camera’s autofocus system could be compromised due to the reduction in maximum aperture. Most are not compatible with any aperture lower than f/8. Manual focus may be necessary in this case. Just make sure your lens aperture and image stabilization are working the same. You want the same shooting information sent to the camera.
Teleconverter Compatibility
Your teleconverter should always fit the camera body and your lenses. Some teleconverters and lenses have elements that stuck out and don’t fit with either. Lens compatibility is the most crucial aspect.
It might be wise to buy the same brand make’s teleconverters. So, if you have a Pentax, go with a Pentax teleconverter. If you have a Sigma lens, you should use a Sigma teleconverter. If you buy a cheaper or generic brand’s teleconverter, always make sure it’s lens compatibility works.
Optical Quality of the Teleconverter
A significant disadvantage of teleconverters is image quality loss. When you use higher magnification, you are only magnifying the central part of the image in the lens. You also capture any defects and aberrations. Matched teleconverters do a great job of being designed to be optically compatible with the lens. So, trying not to get a cheap teleconverter that isn’t matched is critical here.
Matched Teleconverters
A matched aka dedicated teleconverter is explicitly designed for one lens. This is a good option if you tend to travel light as photography and don’t feel the compromising quality.
Brand Teleconverters
Most camera manufacturers offer a selection of teleconverters for telephoto or super-telephoto lenses of their own. And usually, the optical layout is made specifically for their lenses. Some manufacturers include Nikon, Canon, Panasonic, Olympus, Fujifilm, and Pentax. Lens manufacturers like Sigma have teleconverters available for Sigma lenses specifically, but they work on different camera body mounts.
Third-Party Teleconverters
There are specific generic or third party converters like the ones made by Kenko. Kenko’s offers cheaper options with several different mounts for different lenses. Always check the compatibility between the two before purchasing, though. You can check some out on Amazon.
Some Popular Teleconverters:
- Canon EOS Extender EF 1.4x III teleconverter
- Canon Extender EF 2x III teleconverter
- Kenko Teleplus 1.4x HD Pro Teleconverter – Canon fit
- Kenko DG Extension Tube Set for Full-Frame Sony E-Mount
- Nikon TC-14E AF-S Teleconverter III
- Nikon TC-14E II Teleconverters
- Nikon TC-17E II Teleconverters
- Nikon TC-20E III Teleconverter for FX format
- For VR lens: Nikon 16-85mm f/3.5-5.6G ED VR AF-S 2x Teleconverter
Some of the Positive Things About a Teleconverter:
Cost-Effective
They are a much cheaper option than what it would cost to buy a separate long lens. It can also be used on multiple lenses, allowing you to change the focal length of many different lenses.
Extend the Focal length
It is a great device to extend the sufficient focal length, no matter which lens you use. The magnification varies, but we notice the most common one to be 1.4x. Remember, if you’re using an APS-C camera to multiply the number by 1.6 to get focal, you will be seeing.
Light Weight
Longer lenses can sometimes be pretty huge to carry around. A 2X or a smaller device can save your back from some of the strain and damage that a larger lens could bring with it. You can carry fewer lenses if you have a teleconverter in your bag.
Minimal Focal Distance
This device allows you to keep a minimum focal length of the lens you are using. It lets you get closer in on a not very far away subject, especially when you don’t have a macro lens handy.
Some Shortcomings of Using a Teleconverter Are:
Light Issues
The most important thing is that using a teleconverter will mean less light. Less light would also mean a decrease in the widest aperture. A large amount of light comes off the edges of the digital sensor during exposure. The teleconverter magnifies the original image created by the lens. This makes only parts of the light affect the sensor. If you are in low light situations, a teleconverter is probably not the way to go.
Camera Shake Risk
Teleconverters usually increase the size and weight of the lens. It is challenging to keep the camera still while photographing. You may have to slow down on shutter speed and may also want to keep a tripod handy when using a teleconverter.
Lowers Focus Speed
Depending on the lens to lens. Teleconverters tend to reduce the speed at which your camera will focus. However, it may be a lower light issue. You may not be able to use the auto-focus feature while using a teleconverter if using a lower-end DSLR camera. It depends on the camera compatibility.
Image Quality
The extenders magnify and multiply the focal length of your lens. They also magnify and multiply any problems your lens has. For example, there are a few aberrations common in some lenses, so they become worse. Your images will suffer in sharpness when adding another set of optics the light has to travel through. To beat this, use your best lens to keep any reduction in image quality to a minimum.
An Alternative to a Teleconverter
Should you decide to go without a teleconverter, an option would be to crop your picture in the post. Cropping is the cheaper option – however, in my own experience, I’ve seen better results with a teleconverter. You can get away with cropping – but if you want to blow up your images a lot, the converter will be an option to consider.
How to Use a Teleconverter
After learning what a teleconverter is, it’s not very hard to use a teleconverter. Screw your teleconverter onto the body of your camera and the lens on the other side.
Teleconverters can even be stacked. Let’s say you have a 2x teleconverter on a 400mm lens. You now have an 800mm lens. So then, two teleconverters will give you a 1200mm focal length. Pretty cool, huh?
Most photographers will only want a maximum of two or three teleconverters. Otherwise, you will have a hard time focusing, and the contrast will diminish significantly. Make sure you figure out if your lens is compatible with teleconverters first before trying this. Just do so by checking with the manufacturer.
Which Teleconverter is Right for Me?
Sony Teleconverters
If your camera of choice is a Sony, I would recommend the Sony 2x teleconverter lens. This lens is top-rated by Sony customers who believe the picture quality, ease of use, design, and features are excellent.
The Sony FE 2.0x teleconverter is the next best Sony teleconverter. Customers love the performance of the 1.4 teleconverter, which maintains a full version and virtually no CA of IQ reduction. Sony’s superior performance is always a win and sure won’t disappoint those who use this teleconverter.
Best Teleconverter for Canon
It’s important to note that Canon refers to their teleconverters as “telephoto extenders.” Their top-rated best teleconverter for Canon DSLRs is the Canon EF 2.0X III Telephoto Extender for Canon Super Telephoto Lenses.
Customers love this teleconverter for its clean and crisp images. Do note that you may also get slower autofocus because of the reduced adequate aperture size. That is usually something that can happen with teleconverters.
Nikon 2x Teleconverter Compatible Lenses
Nikon also sells its particular kind of teleconverters, compatible with their cameras that don’t have to be checked. Customers who work with a Nikon camera are pleased with these teleconverters. If you’re using bright light, the picture quality comes out unique. The teleconverter still allows the camera to do autofocus, which solidifies their excellent rating.
Nikon lovers rejoice, as the Nikon AF-S FX TC-14E III (1.4x) Teleconverter Lens with Auto Focus is another top choice for Nikon lovers. A good thing to know is that the Nikon F lens mount supports both FX and DX-format AF-S NIKKOR lenses. It won’t be so hard to find compatible models.
Customers love this teleconverter because of the rich results they get by using it. Nikon customers also love the sharpness and color that comes from using this teleconverter. Catch images of the moon, birds, animals, and sports games with clarity.
Tamron Teleconverters
Tamron sells its own 2x teleconverters, which work with different camera models. These teleconverters are not as higher-rated as the other brand-name teleconverters but may be easier if you can’t see to find the most compatible teleconverters. If you have a decent camera, you should get the best shots out of this one or any other teleconverters on our list.
FAQ: Should I Use a Teleconverter?
A camera captures picture-perfect moments. Sometimes that extra zoom is what you need to click a perfect picture.
Having the right lens in every situation would be the ideal thing for every photographer. Buying a new lens with the required features can be a rather expensive affair for those on a tight budget. One solution to this problem is getting a teleconverter.
When the situation arises, you can mount the teleconverter between the camera and the lens and extend your focal length.
Using a teleconverter has its pros and cons when discovering what a teleconverter is. And it will be your ultimate decision if a teleconverter is right for you.
What is a Teleconverter? – Conclusion
Using extenders/teleconverters is a more affordable way to extend your focal length than to purchase a longer lens. However, the cost can be to your image quality and camera performance. If you can use a longer exposure time, you will be in better shape. If you are not working with decent light, I would stay away if I were you.
I think they are well worth using if you need the extra reach but wouldn’t use them for every shot. I travel with a 1.4x extender at all times when shooting with my 70-200mm lens, just in case I need to get a little tighter of a shot. And it doesn’t take up much room in my camera bag as another lens would.
When using one, try not to use them at the maximum aperture that your camera will allow – but stop it down at least one stop, and you’ll find the results are significantly better. Also, keep in mind that longer focal lengths will leave you with less depth of field to play with – so your focusing needs to be spot on!
