Maximizing the Canon RF 100-300mm L Lens: Unleashing Its Potential with the EOS R7 – Part 3

All photos taken with Canon EOS R7 using RF 100-500mm L, handheld

The Canon RF 100-500mm f4.5-7.1 L IS USM is regarded as one of the top and most flexible telephoto zoom lenses in Canon’s RF mount lineup.

However, on a full-frame camera, it may not provide enough reach for bird photography.

In earlier discussions, I explored cropping techniques and using the RF 1.4 Extender to enhance the lens’s effective distance.

To summarize, pairing the 100-500 with a high-resolution body like the R5 or R5.2 ensures great results and excellent autofocus, allowing significant cropping with minimal loss in image quality.

When using a body with lower resolution, such as the R6 or R6.2, adding the 1.4 Extender can be beneficial. Although autofocus isn’t quite as responsive as it is with just the lens, it remains impressive. Image quality is still good, but there is a reduction of one stop in aperture.

One downside of attaching the 1.4 Extender to the 100-500 is that the lens needs to be zoomed out to 300mm for it to function properly. This limits the focal length range to 420-700mm.

Another option is to use the lens with the R7 body, which gives us an equivalent focal length of 160-800mm. This range is ideal for birdwatching, and with a 32 MP sensor, cropping is feasible.

I’ve been utilizing the R7 option for a year and find it highly effective for most situations, though there are some concerns with capturing birds in flight.

Below is a comparison chart of the costs, based on current prices from a vendor in Australia at the time of this publication.

Clearly, the R7 option is the most budget-friendly.

It also offers a flexible setup capable of delivering impressive results in various scenarios.

For still birds or moving subjects at moderate speeds, the R7 maintains focus effectively while tracking. I prefer using a fast shutter speed, the electronic first-curtain shutter, and Drive Mode [H] which allows for 7 frames per second without any shutter shock or rolling shutter distortion.

Drive Mode [H+] increases the speed to 15 fps with EFCS, but at the cost of a lower keeper rate.

The R7 handles airplanes, speedboats, and most sports well. However, it struggles more with birds in flight compared to full-frame cameras, which present the toughest autofocus challenges. While the R7 can capture birds in flight, it has a lower keeper rate than the R5.

On the whole, I’ve found the R7 to be such a good match with the RF 100-500 L zoom that I’ve sold my full-frame cameras without any regrets.

This is a cropped version of the above photo.