Probably you would say yes. Because the biggest need for bird photography is the reach. No matter the focal length you currently have, it’s never enough. Isn’t it?
Teleconverters extend your current focal length of the lens by a factor of 1.4x, 1.7x, or 2.0x. Which means, if you put a 1.4x teleconverter on a 300mm lens fixed to a full-frame sensor, your effective focal length would be 300mm x 1.4 = 420mm. If you place a 1.7x teleconverter, it’d be 300mm x 1.7 = 510mm. And a 2.0x teleconverter gives you a 600mm (300mm x 2.0) equivalent!
It’s amazing, isn’t it? And the cost of these teleconverters is just a fraction of the lens.
Essentially, if you buy a (Nikon) 300mm f/2.8 at the cost of US$ 5,000 and buy a (Nikon) 2.0x III teleconverter at just US $500, you’ll end up getting an equivalent of 600mm f/5.6 lens (we’ll talk about the f-stop later). The combination is just US $5,500.
Isn’t it bang for the buck, as a (Nikon) 600mm f/4 lens (new version) is around US $12,000?
Not really. If it were truly equivalent to a 600mm, lens manufacturers wouldn’t have ever spent millions of dollars to manufacturer prime lenses. Does it make sense to make something so expensive when photographers can get away with 300mm f/2.8 + 2.0x teleconverter combination?
That’s where the below 5 key factors come into play when you are using a teleconverter. Let’s discuss them.
5 KEY FACTORS TO CONSIDER WHILE USING A TELECONVERTER
Here’s a quick look at what are the factors that affect a lens performance when you use a teleconverter:
1. LOSS OF LIGHT
You’ll lose 1 stop, 1.5 stops, and 2 stops when you use 1.4x, 1.7x, and 2.0x teleconverter, respectively. For instance, your 300mm f/2.8 lens becomes a 420mm f/4, 510mm f/4.5, and 600mm f/5.6 equivalent when used with 1.4x, 1.7x, and 2.0x teleconverters, respectively.
If you are not acquainted with stops or f-stops terminology, I strongly recommend you to read the article Photography Basics – Aperture before proceeding further.
Here’s an easier interpretation of the loss of light due to the use of teleconverters:
300mm f/2.8 + 1.4x teleconverter = 420 mm f/4 (1-stop loss)
300mm f/2.8 + 1.7x teleconverter = 510 mm f/4.5 (1.5-stop loss)*
300mm f/2.8 + 2.0x teleconverter = 600 mm f/5.6 (2-stop loss)
* In theory, 1.5 stops from f/2.8 should have been f/4.8 not f/4.5. But as the manufacturer’s use 1/3rd stops as intermediate f-stops, the f-number we get is f/4.5. If it’s true, then we are just losing 1.33 stops. I haven’t ever used a 1.7x teleconverter, so I cannot test it. I am assuming this is the case.
Loss of light can seriously impair the autofocusing capabilities and would result in slower shutter speeds as discussed in the below points.
2. AUTOFOCUS PERFORMANCE DEGRADES
Loss of light directly affects the autofocus performance. Remember that the autofocus depends on the incoming light to detect the contrast and the phase thereby detecting the subject and its movement respectively.
Depending on the teleconverter you are using, you might experience serious lag in autofocus. This especially becomes apparent when you use a 2.0x teleconverter as it loses 2-stops.
This is a serious problem as the birds are extremely quick. Which means achieving the autofocus as quickly as possible is vital to getting best photographs. Any loss in autofocus performance can be awful.
Smaller teleconverter would result in smaller degradation in performance. For instance, 1.4x teleconverter often doesn’t degrade it a lot, as opposed to a 2.0x teleconverter which is easily noticeable.
3. LIMITED AUTOFOCUS POINTS OR NONE AT ALL
Most entry level cameras don’t have the capability to autofocus beyond f/5.6. Which means, if you use a 2.0x teleconverter on a 600mm f/4 lens, you wouldn’t be able to autofocus. That’s because, with 2.0x teleconverter, the maximum aperture of a 600mm f/4 lens becomes f/8.
Assuming that you have a prosumer or a professional camera bodies like Nikon D5, D4, D750, D800, D7200, Canon 1DX Mark II, 5D Mark III, 7D Mark II, etc. you’ll have autofocusing capabilities up to f/8.
When the maximum aperture of the lens is f/8 (due to the use of a teleconverter), you’ll only be able to use limited autofocus points. Usually, only the center autofocus points work when the lens is at a maximum aperture of f/8.
Note: Don’t get confused with setting the Aperture of the lens to f/8 v/s using a teleconverter. No matter whether you set a lens at its maximum aperture or the minimum aperture, you’ll get to use all the autofocus points. That’s because your lens is always working at the maximum aperture until you dip the shutter. Wonder how? Ask me later.
Check the compatibility of the lens and the autofocus limitations in the following charts for Nikon and Canon users.
4. SLOWER SHUTTER SPEEDS OR HIGHER NOISE
As discussed in the first point, using a teleconverter leads to the loss of light. The loss of light is due to loss of f-stops. This loss in aperture has to be compensated either by decreasing the shutter speed or increasing the ISO.
Read about the Exposure Triangle to understand the interplay of Aperture, Shutter Speed, and ISO to achieve a proper exposure.
As the shutter speed plays a critical role in freezing the action, most often, you cannot slow it down any further. So, you are left with the only option – to increase the ISO. Any increase in the ISO value would result in noise. If you are using a cropped sensor camera (APS-C or DX), then noise can be extreme and makes the photograph unusable.
5. SOFTER IMAGES
Most often the teleconverter renders an image much softer than if it was taken with just the lens. This is because of the loss of light due to the use of teleconverters. The loss of light indicates loss of contrast which results in loss of sharpness. Which ultimately results in a softer image.
The issue can have the extreme impact when used on a softer lens. Say you are using a 1.4x teleconverter on an 80-400mm f/4.5-5.6G lens. Compared to a prime lens, this lens is not very sharp, especially when it’s wide open. When coupled with a 1.4x teleconverter it makes the matter worse. In fact, most zoom lenses are inferior in terms of quality and sharpness.
The softness of the image can be too much especially with 2.0x teleconverters. That’s because of the 2 stops light loss. This was quite a bothersome experience for a lot many photographers who were frustrated. It still is.
I have used the combination of 300mm f/2.8 + 2.0x teleconverter quite successfully. In fact, you can find many photographs in my bird photography eBooks taken with this combination.
Here’re just 2 photographs from the above said lens and teleconverter combination.
Alright, the above 5 key considerations before going for a teleconverter might look scary, but they also have advantages. Here’re some key advantages of using a teleconverter.
1. GIVES MORE REACH
Of course, this is the very reason you buy a teleconverter. Don’t you?
A bird photographer is always on the look out of more reach. If there’s a 2000mm lens, every bird photographer would love to have it. Reach, reach, and reach is probably the only thing an amateur photographer thinks about. He would say…”if you give me long enough focal length, I will make the best bird photographs.”
Really? Are you sure about this?
Teleconverters definitely are a very important accessory for any serious bird photographer. But, it shouldn’t be considered as a replacement. Ever. A 400mm f/2.8 + 2.0 teleconverter (effective 800mm f/5.6) is NEVER same as a 800mm f/5.6 lens. Why? Read the 5 key considerations that I wrote above.
If you have read my Bird Photography Simplified – A Virtual Masterclass eBook, you already know many different ways to approach the bird. It really is the key to the success in bird photography. In fact, there’s no focal length which will ever be sufficient. That’s the beauty of photography. It’s the most challenging one!
Most often you’d be using your actual lens for photography. But sometimes, you might have done everything you possibly can, but may still need some more reach. That’s when you’d use a teleconverter. The situation should call for it.
The beauty is, however, you can decide whether to go for 1.4x, 1.7x, or 2.0x teleconverter. You have a choice. That’s important. Decide on how much of a degradation in performance can you accept. And act accordingly. As said earlier, 1.4x is better than 1.7x which is better than 2.0x teleconverter.
2. YOU’LL GET SEVERAL DIFFERENT FOCAL LENGTHS
Isn’t it great to have multiple focal lengths from the same lens? It is.
By using a teleconverter, you can have 2 or 3 different focal lengths with one lens! That’s the beauty of it. Say you have a 300mm f/2.8 lens which is an amazingly sharp lens and most versatile lens as well. Now, by having 1.4x, 1.7x, and 2.0x teleconverters you can actually increase the focal length of this lens to 420mm, 510mm, and 600mm respectively. If you are very well aware of the 5 key factors that affect the performance of your lens and can work with these limitations, then you have a solid combination!
The key here is…work with the limitation. Remember that you have a limitation regarding the loss of light, autofocus degradation, shutter speed reduction, softer images, and limited autofocus points (@ f/8).
With the above thought process, you’ll have much better mindset than constantly debating or fighting about the pros and cons of these teleconverters. It’s useless at best.
3. THE TELECONVERTER LENS COMBINATION IS MUCH LIGHTER
For some people, the combination works out much better as it’s much lighter. A 300mm f/2.8 + 2.0x teleconverter is hand-holdable compared to a 600mm prime. 600mm prime lens is hefty and mostly impossible to hand-hold for more than a minute.
Though there are tripods and gimbal heads which go along extremely well with a 600mm prime, the whole setup is ultra-expensive and heavier to carry.
In such cases, you might want to decide to go with a lighter combination. But remember the limitations that come with it. Be reasonable with the expectations. And more importantly, be happy,whatever the choice.
4. TELECONVERTER IS THE ONLY OPTION
In some cases, the teleconverter is the only option. For instance, we don’t have a 1200mm lens. So, a 600mm f/4 lens with a 2.0x teleconverter is the only option. Of course, a real good one. You know why? Because we don’t know the quality of a 1200mm prime. So, whatever we get is the best. You see… I am an optimist 🙂
In fact, many experienced photographers seem to always put a 1.4x teleconverter in front of their 600mm f/4 lens. It’s odd but true.
Same is true with 800mm f/5.6 lens. With a 1.4x teleconverter, you get an effective focal length of 1200mm f/8. That’s a good choice as well.
It doesn’t really hurt to use a teleconverter. All that’s necessary for you to understand is that you have to work with the limitations.
Personally, I have used the teleconverters only when the situation demands. I am always very happy with the quality of the image that my native lens gives. I hate it when I lose the autofocus performance. For me, it’s a deal breaker. Check why I say autofocus system is extremely important in my article Choosing the Camera Body for Bird Photography.
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It’s a very lengthy article, but I think well worth the effort. I hope you have read it thoroughly. If not, I urge you to read it again.
Here’s a quick round-up about the pros and cons of the teleconverters.
5 key factors to consider while using a teleconverter are:
- Loss of Light.
- Degraded Autofocus Performance.
- Limited Autofocus Points in some cases.
- Slower Shutter Speeds or Higher Noise.
- Loss of Contrast and Sharpness Resulting in Softer Images.
And then, some advantages of teleconverters are:
- You’ll Get More Reach
- You’ll Get Several Different Focal Lengths
- The Teleconverter + Lens Combination Is Much Lighter.
- Teleconverter Is The Only Option.
That’s it for today. I hope you enjoyed reading this article. Hopefully, it helps you understand the pros and cons of using the teleconverters very well now.
I would love to hear your experiences with teleconverters. Write the teleconverter + lens combination you often use in your bird photography.
Any other questions, please?
Talk to you soon…
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