The Straightforward Video Guide to Teleconverters

I consider teleconverters to be an essential piece of photography gear for wildlife photography. Check out this great video on what makes them special and how to get the most out of them.

In this video, Steve Perry explains how teleconverters work, their effect on image quality and autofocus speed, and best practices to using them in the field. I use a 1.4x teleconverter paired on a 500mm f/4 lens a majority of the time. With quality glass, there should be little hesitation to add them on when the shot requires more reach.

Pied-billed Grebe. Canon 500mm f/4L IS USM + 1.4x III Extender.

One thing I wish was set straight here is how teleconverters affect depth of field. There’s enough conflicting information found from different sources that I wouldn’t mind a more scientific breakdown on it. Perry says that a 400mm f/2.8 with a 2.0x teleconverter would be an exact depth of field match to 800mm f/5.6. However, I’ve heard elsewhere, for example from Moose Peterson, that it would be more somewhere between f/2.8 and f/5.6. Using the PhotoPills depth of field calculator, it’s not an exact match, although it’s pretty close to the higher f-stop number. Commenters, feel free to flex your knowledge below.

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Stuart Carver's picture

I just wish Fuji would release one for the 55-200.

Adrian Morton's picture

Good post . I've been using the TC1401 from Sigma with my 120-300 f2.8 sport lens with excellent results, giving equivalent 420mm focal length. DOF I would say feels better than F4 when right out at the max focal length, downside is the extra stop of light that results in a knock down in shutter speed or increase in ISO. Only noticeable under poor lighting conditions, and if that's the case then off it comes, with the D810 still plenty of pixels to crop in.
I've just bought the TC2001 to pair with the sigma 120-300 sport as for some sports I cover I need that extra reach and 600mm @ f5.6 seems a fair compromise. However it's a little disappointing, so much so that shooting with the 1.4 and cropping in gives me in my opinion a much sharper image. Now this maybe due to the inability to calibrate the lens with a TC on and the camera to recognise the difference between the lens with and without a TC, the lens has been calibrated/AF tuned but with no TC for my body.
I've only used this twice so far, a little more experimenting required, maybe I've missed a trick but lens on a gimble shutter >1/1200th so wasn't expecting the softness in the resulting images.

Interesting if anyone has experience with the TC2001 on this lens.

EL PIC's picture

I use a 1.4 Canon series II with the 100 400 L zoom series I.
I would like more explanation on the series I , II , III and how they differ other than you need to use xxx with thistle lens.
In other words .. how are they compatible and optimized or is it just marketing.
Lone Puffin with 1.4 x and 400 mm L (f / 8 560 mm 1/8000 sec) on a bouncing boat.

LA M's picture

Don't forget to mention the downsides....image degrading due to heat blooming etc.

Simon Pierce's picture

Steve's videos are great. His ebooks are brilliant, too. I've learnt a lot from his stuff.