Canon RF 100-400mm f5.6-8 IS USM lens User review 5 December 2021

 

Hey is that the new RF 100-400mm ?

Canon has taken he opportunity  offered by the new RF mount to introduce a series of lenses each of which offers something desirable to users when compared to that which was available in the EF mount system.

A good example is the subject of this post, the RF 100-400mm f5.6-8 IS USM zoom introduced in 2021. 

By the way this new RF lens is not on the upgrade path from the EF 100-400mm F4-5.6 L.

The RF system upgrade from the EF 100-400 L is the RF 100-500mm f4.5-7.1 L IS USM. These are big white L zooms which are larger, heavier and much more expensive than the non-L models.

Canon’s strategy has for many years been to offer desirable products at the top, middle and entry level of the price/capability range. In recent times “entry level” has moved upmarket as the bottom drops out of the low cost budget end of the range.

So it comes to pass that a quite advanced and sophisticated product like the subject of this post finds itself representing the entry level of the consumer super zoom segment of the catalogue.

An attractive entry level kit for the RF system could include an R or RP body with the 24-105mm STM standard zoom plus the 100-400mm f5.6-8 zoom. This covers the range from very wide to very long with just two lenses both of which are light,  compact  and moderately priced.

Plenty of clean detail with the RF 100-400mm

Canon RF long lens options  Although it is early in the life of the RF mirrorless system there are already many options from which to choose.

At the top we have the RF 400mm f2.8 L and the 600mm f4 L for professional sports photographers. These deliver the best image quality and performance but are big, heavy and very expensive.

Moving down the primes we come to the RF 800mm f11 and 600mm f11. These offer serious super tele reach at budget prices making them very attractive to enthusiast long lens users.

The RF 600mm f4L is 15 times the price of the RF 600mm f11 but is certainly not 15x better.

In zoom world we have the RF 100-500mm L at the top. This is a really excellent lens which is also compact for the focal length range and within the budget of many enthusiast photographers.

There is also the EF 100-400mm L which can be mounted to RF cameras with the requisite adapter. I would not buy one of these new but anyone who already has one can mount and use it on any RF mount body.

Last but by no means least we come to the subject of this post which is the RF 100-400mm f5.6-8 IS USM released in 2021.

This lens is the RF system upgrade to the EF 70-300mm f4-5.6 (2) IS USM of 2016. The new lens  delivers greater reach at the long end, greater maximum image size for close-ups, lighter weight, faster AF with better tracking of fast moving subjects and very nice handling.

It is remarkably light and compact for a full frame lens reaching out to 400mm.

Sometimes the photo doesn't quite tell the story. In the hand the 100-500mm feels considerably larger and heavier than the 100-400.

Although it fits in the budget category I find this lens rather more convincing overall than either the RF24-105mm STM or the RF 24-240mm zooms.

As with all Canon’s non-L lenses there is no lens hood in the box and weather sealing is not provided. The construction appears to be all plastic except for the mount but it is well made. The zoom action is very smooth with just the right amount of drag. A zoom lock button is provided but I have never felt the need for it.

There is a wide zoom ring in mid barrel. In front of that is the manual focus ring and right at the front is an RF style multi-purpose control ring.

There is an AF/MF switch and a Stabiliser On/Off  switch but only one general purpose Stab mode which appears to work very well.

So although it is not an L lens it is well specified for use by an enthusiast photographer.

Optically there are 12 elements in 9 groups with one aspheric element, one UD element   and superspectra coating. Focus is by nano USM.

Lens construction schematic

MTF chart

Autofocus is very fast and accurate on still or moving subjects. The lens is very suitable for sport/action/wildlife/BIF.

On my tests the stabiliser allows me to make sharp pictures hand held at about 3.5 EV steps slower shutter speed than without the stabiliser. This is the same stabiliser benefit that I have achieved with every RF lens to date on my EOS R5 body.

Sharpness is very good across the frame and into the corners right from the maximum aperture at 100-300mm focal lengths.

At 400mm sharpness decreases a little but is still very good in a large central area, with some reduction in sharpness and shading evident towards the periphery.

When I tested this lens Adobe did not yet have a profile available but even without the profile my test shots show negligible color fringing.

Update 15 December 2021: The profile is now available and my test images using this show very clean sharp output with virtually no faults. 

There is very slight pincushion distortion across the focal length range.

Flare can be induced but is not a problem in normal use.

The out of focus rendition (bokeh) looks decently smooth to me although backgrounds will always be busier with this lens than one of the L models which have a wider maximum aperture.

With a maximum magnification level of 0.4x at 400mm macro shots are easily obtained without needing to be very close to the subject.

It might not be apparent from the size comparison photos but in use this lens feels much lighter, more compact and easier to manage than the RF 100-500mm L.

Of course it does not have the ultimate image quality of the four times more expensive L lens but in many conditions it comes quite close even in low contrast or backlit situations.

The lens is compatible with both the RF 1.4x and RF 2x extenders which can be mounted without having to extend the zoom. I will report on results with the 1.4x extender when these are available.

Update 15 December 2021: I have tested the lens with the RF 1.4x extender. Results are very good. Overall sharpness and contrast at 560mm f11 are very good. Autofocus is fast and accurate even with animal/bird eye tracking. The stabiliser is effective. The lens is definitely usable with the 1.4x extender.

Update 28 January 2022:  Today I tested the RF100-400 vs the RF 100-500 both at 400mm f8. My test subject for long lens tests comparisons is a grove of Casuarina trees about 700m from the camera.

Comparing the Raw files side by side on screen at 100%.  Without looking at the exif data  I could not tell which image came from which lens anywhere in the frame.  I am very familiar with the 100-500 which is really excellent.  This result makes the 100-400 look like remarkable value for money and an excellent lens in its own right.

Overall this is an appealing offering from Canon which is easy to recommend.  I think many enthusiast photographers will be very pleased with this lens.

 

R5 RF 100-400mm f5.6-8 plus RF 1.4x extender. 560mm, 1/500 sec at f11 ISO 8000.