Canon Rf 70-200 F4 Vs F2.8

By | 06/07/2022

Offset off: this is not a review. This is a simple test under controlled conditions to evaluate image quality of these 2 compact L-serial telephotos. A full review of the RF lxx-200mm f/4L IS can be constitute here, while my review of the RF 70-200mm f/2.8L IS can exist found hither.

In Nov, Catechism expanded their f/4 series of L zoom lenses with the RF lxx-200mm f/4L IS, an extremely compact high-cease lens that is barely larger than the RF 24-105mm f/4L IS. At $ane,600, it’s not a cheap lens, but it is still a full $one,100 less expensive than its also meaty, faster brother, the RF 70-200mm f/2.8L IS. I have both lenses in my possession, and wanted to put out a quick comparison between the two lenses.

The Lenses

Canon has gone with a new exterior design for their 70-200mm zooms for mirrorless, eschewing the standard internal zooming design for these lenses. The upshot is an extending butt blueprint that dramatically cuts down on size and weight in comparison to their DSLR counterparts.

The Canon RF 70-200mm f/4L IS (left) and RF 70-200mm f/ii.8L IS (right), at 70mm

Canon RF 70-200mm f/two.8L IS USM:
The f/ii.8 version of the lxx-200mm L lens is very compact for a fast telephoto at just v.75″ (146mm) long and 2.35lbs (1070g). This is several inches shorter and virtually 400g lighter than the latest EF seventy-200mm f/two.8L.

Canon RF 70-200mm f/4L IS USM:
The f/4 version of the 70-200mm L lens is fifty-fifty smaller, beingness significantly lighter and fifty-fifty a full inch shorter, despite the same focal range. The 70-200mm f/4L IS weighs in at a mere 1.five lbs (695g) with a length of just 4.7″ (120mm).

Both lenses are congenital to high standards, simply upon close examination, the f/2.8 version is the more robustly constructed lens. The extending butt of the f/4 version has just a minor fleck of play, while the f/2.8’s barrel is exceptionally rigid. The smoothness of both zooms is outstanding, and both feature manual focus rings, control rings, and the full complement of focus and stabilization switches, as well every bit a zoom lock.

The Canon RF seventy-200mm f/4L IS (left) and RF lxx-200mm f/2.8L IS (right), at 200mm

Both lenses feature optical image stabilization, and both are sealed against grit and moisture. The larger f/ii.viii version comes with a tripod neckband for improve residual while tripod mounted. Both take fast and accurate autofocus. While the focal lengths are the same, I did notice that the f/4 version exhibits slightly less focus breathing at close focusing distances. In these tests, at 200mm, the f/4 version had a slightly tighter field of view, probably around ten-15mm longer than the f/2.8 version. Of course, well-nigh infinity, the field of view is virtually identical.

In all, these are ii great compact pro-level zoom lenses. But how practice they compare optically?

The Examination

Every bit I mentioned, this is simply a quick test at ane focus distance, and is not meant to be the end-all be-all comparison betwixt these two lenses. For this test, I fix my 45 megapixel EOS R5 on a tripod, aimed at the exam scene. The point of focus was approximately 1.25m away. I placed a crystal decanter in the background to provide some specular highlights so I could take a wait at the bokeh of the lenses. I tested each lens at 70mm, 135mm, and 200mm, at full aperture stops from wide open through f/eight.

Beneath is the test scene, at 135mm, f/4, with the 70-200mm f/4L:

Test Scene – Catechism EOS R5 with Canon RF 70-200mm f/4L IS USM

I took 400×400 pixel crops from the most middle of each test image, too equally from the nigh corner of each paradigm. Note that considering of changes in focal length, the corner constitutes a different spot at each focal length. Too, at 135mm and 200mm, the corner crop is slightly different for each lens due to slightly different amounts of focus breathing, such that the f/iv version was slightly tighter into the scene than the f/2.viii version.

The crops are presented beneath for each focal length tested, and are 100% pixel crops. Click on the paradigm to open it larger. Exist sure to magnify to view at 100%.

100% Crops @ 70mm (click to view full size)

Looking at the to a higher place, both zooms testify impressive resolution in the central area correct from their maximum apertures. The f/2.viii version is slightly sharper when both are at f/iv, but it’s an extremely small difference. The corners are a different story. The f/two.8 lens shows a bit of softness at f/2.viii, which improves upon stopping down, until it is abrupt at f/8. The f/4 version, withal, is fairly soft at all discontinuity settings, with balmy comeback at f/8.

Now let’s take a look at 135mm:

100% Crops, 135mm (click to view full size)

At 135mm, once once more, both lenses are first-class in the center, straight from their maximum apertures. One time once more, the corners are notably better on the f/2.8 lens, with it being very abrupt to the corners right from f/2.8. Stopping downwards eliminates vignetting and shows a moderate increase in sharpness. The f/four lens is a bit softer, but resolution is ok. Unfortunately, it doesn’t improve that much upon stopping downwards.

Now let’due south take a look at 200mm:

100% Crops, 200mm (click to view total size)

Here, the f/2.8 lens shows good resolution at f/two.8 that improves to splendid resolution at f/4. The f/4 lens is quite precipitous at f/iv, and a bit sharper than the faster zoom is at f/2.eight, but not quite as precipitous as it is when closed downward to equal the f/4 aperture. Beyond f/4, both lenses are incredibly sharp in the center, with very petty difference between them.

In the corner, still, we have proficient resolution from the f/2.8 lens at f/2.8 and f/4, improving to excellent resolution at f/5.6 and f/viii. The f/4 lens, still, has something a bit strange going on here. First, it’s soft in the corner at f/4, but it actually gets
as you lot terminate down.

Needless to say, this is a scrap unusual. When I noticed this later taking the test shots, I retook the 200mm shots for the f/4 lens multiple times, each time with the same result. All of the above crops were taken from the aforementioned image, with focus at the center. However, it appears the f/4 lens shows some field curvature that worsens when stopping down. To ostend this, I took a shot from the same position, merely focused in the corner, and the departure is stark:

100% corner crops, RF seventy-200mm f/4L @ 200mm, f/viii, focus on center and corner

While the corner isn’t blisteringly sharp when focused there, it is a big comeback on the lens when focused on the middle, indicating that at long focal lengths and small apertures, in that location is field curvature that will touch corner sharpness on flat subjects. The f/two.viii lens, however, has a flat field of focus.

After running the above tests, I wanted to run across how long that field curvature posed a problem, so I did an boosted test the following morning, at a focus distance of 3m. I simply present the f/four and f/8 crops at 200mm below:

100% Corner Crops, 3m focus distance, focused at heart (Click to Enlarge)

Hither things look much better for the f/4 zoom. The field curvature withal knocks a touch of sharpness from the lens at f/8, only it isn’t bad at all, and remember, this is the extreme corner on a 45 megapixel sensor. Overall, the two lenses are rather shut at this further focus distance, with a very slight edge to the f/2.eight zoom.

In all, both lenses perform quite well, but through a combination of optics and some field curvature, the f/2.8 version shows meliorate corner sharpness throughout the range, at to the lowest degree on flat field subjects at closer focusing distances.


At present let’s take a quick wait at bokeh. I didn’t want to get likewise into the weeds here, and then I took crops from the same location on the decanter for both lenses at a diversity of apertures at 200mm.

Bokeh crops, 200mm (click to enlarge)

Hither there really isn’t a whole lot to pick betwixt. Both lenses show very pleasing bokeh, with no vivid ring outlining, smooth transitions between highlights and no obvious fringing. The slight blue hint around one of the highlights is non imperial fringing of the lens, but rather color from the light through the decanter.) The f/2.8 lens can patently create more blur with the one stop faster aperture, and as these spots are near the edge of the frame, maintains rounder highlights when both are at f/4. However this one is pretty much a wash.


So there yous have it. One test at one focus distance. And the winner? I have to give information technology to the f/2.8 for the more even performance with regards to resolution. Does that hateful the f/2.eight lens is better in every situation? Nope. Bank check out my full reviews of these lenses for more information.