Canon RF 35mm f1.8 Macro IS STM lens Two year user report 24 November 2021

Boronia serrulata

How time flies when you’re having fun. I realised recently that I have been using Canon full frame mirrorless cameras and the RF 35mm f1.8 Macro STM lens for over two years.

So I figured it is time for a two year long term user review of this lens which as it happens was the first one which I purchased on moving to the new RF mount

I have used the RF 35mm f1.8 STM on RP, R and R5 cameras in a wide range of situations including landscape, street, documentary, flower close-ups and anything else which takes my interest. This has produced many thousands of frames and plenty of opportunity to thoroughly evaluate the lens over time.

Many photographers would select the 35mm focal length if they had to go forth with just one prime lens. Many prime lens compacts over the years have used this focal length.

It is wide enough for landscapes, street and documentary work but long enough for group portraits and environmental portraiture.

The RF 35mm f1.8 Macro adds the party trick of being able to function as a decent macro lens with a maximum magnification of 0.5x.

This is yet another example of the ways Canon is using the mirrorless RF mount to develop lenses with capabilities and characteristics not previously seen.

With the 35mm focal length it is reasonably easy for lens designers to deliver good optical and mechanical quality while maintaining a compact size and modest price.

No surprise then that the 35mm focal length has been one of the most popular in the Canon catalogue for many years.

Canon has been producing 35mm primes for over 70 years and I think it is fair to say they have gotten pretty good at it.

In the era of rangefinder bodies between 1946 and 1964 Canon produced eight models with the 35mm focal length. Their apertures ranged from f1.5 to f2.8.

In the single lens reflex film era from 1959 to 1989  twelve 35mm lenses were produced with apertures from f2 to f3.5.

The electronic EF mount was introduced in 1987 with autofocus.

The 35mm f2 appeared in 1990. I used one of these on various Canon SLRs for several years through the 1990s. It was a nice compact lens with good central sharpness but was noticeably soft at the edges at any aperture.

In 2012 the EF 35mm f2 USM arrived  with an image stabiliser, 10 elements in 8 groups and a maximum magnification of 0.24x.

 This lens is still listed for sale by some vendors and is still in the EF lens catalogue on the Canon Australia website. However it is larger and considerably more expensive than the RF 35mm f1.8 which must  limit its appeal. In addition the number of DSLRs being offered for sale is steadily decreasing and there is no point buying the EF version to mount on an RF mount body.

When Canon eventually entered the full frame mirrorless market towards the latter part of 2018 they announced four RF lenses, two primes and two zooms.

One of the zooms is the 28-70 f2 L, a high end professional model not seen previously.

The other is the 24-105mm f4 L pitched at the enthusiast market.

One of the primes, the 50mm f1.2 is a high end pro model.

The other is the subject of this review, the RF 35mm f1.8 Macro IS STM.

Compared to the EF 35mm f2 USM the new RF lens has a wider aperture, is more compact, less expensive, better optically  thanks to a completely different optical formulation and it offers half  lifesize macro capability.

The only potential downside of the new lens is that it utilises a stepper motor (STM) for focussing. Such motors are efficient but could be slower than ultrasonic (USM) types.

This is a jack-of-all-trades kind of lens which can handle pretty much any assignment for which a 35mm focal length is appropriate.

Its size and price point pitch it at the entry/hobbyist sector but its optical quality places it very much in enthusiast/professional territory.

My experience with the lens is that it can transfer a remarkable amount of detailed information from subject to output file particularly when mounted on a high pixel body such as the R5.

Design evolution 1990-2018

In 1990 the EF 35mm f2 had 7 elements, no aspherics.

In 2012 the EF 35mm f2 IS had 10 elements with one aspheric.

In 2018 the RF 35mm f1.8 got 11 elements with one aspheric.  The RF looks almost like a reverse version of the 2012 EF lens. The whole thing has been turned around. Now the front element is small and the rear element large and close to the sensor.

You can read more about Canon MTF curves here  https://www.usa.canon.com/internet/portal/us/home/learn/education/topics/article/2019/april/Reading-and-Understanding-Lens-MTF-Charts/Reading-and-Understanding-Lens-MTF-Charts

Description

Like many RF lenses the 35mm f1.8 offers understated styling in semi matt black. Length is 63mm, diameter 74.4mm, mass 305 grams. Filter size is 52mm.

There are no bayonet lugs on the front of the outer housing of the lens barrel.

The small circular Canon EW-52 hood (not supplied in the box) screws into the filter thread or into the front thread of a filter if one is fitted.  When fitted this hood increases the effective length of the lens by about 10mm.

A more conventional looking JJC LH-RF35F18 petal type reversing bayonet mount hood is available. This uses a press-on type bayonet adapter fitting.

My copy of this hood can be a little fussy to reverse mount bur is otherwise trouble free.

At the front of the outer housing is a clicky control ring which can be used for any one of a variety of user selected functions.

Behind this is the focus ring.

Towards the rear on the left side are the AF/MF and Stabiliser On/Off switches.

The lens is not weather sealed.

About filters

There are often arguments on user forums about the merits of fitting a protect filter to lenses.

The case against filters usually is expressed as….”why would you buy an expensive lens then put a cheap filter in front of it ?”   Indeed why would you ?   But a high quality,  expensive filter is a different proposition.

 I often use my camera gear at the seaside where it usually gets a dose of salt spray and in the bush where it encounters dust, pollen, and dirt. So I mount a B+W MRC protect filter and leave it there. It is much easier and safer to clean the filter than the front element of the lens and I have not found the filter to have any significant adverse effect on image quality or focussing.

Stabiliser effectiveness

Canon claims that the RF 35mm f1.8 on a stabilised body like the R6 or R5  will give 5 stops of advantage  “based on the CIPA standard”.

My real world tests show that on the EOS R5 at normal focus distances the image stabiliser lets me get sharp pictures hand held at a shutter speed on average  about 3.5 EV steps slower than I can achieve without the stabiliser.    In the macro range stabilisers are less effective but still useful.

Focus

The front element of the lens extends about 18mm when the lens is focussed at its closest possible distance.  At this point I guesstimate the effective focal length to be around 50mm.

Focus is achieved by moving the front 9 of the 11 elements. This is not slow but some USM lenses are faster.  In general photography at distances over a meter or so, One Shot AF is quick enough that I can just get on with making the shot without having to be concerned about the focussing process.

AF acquisition slows a little in very low light but the lens is perfectly usable in very dimly lit environments.

AF accuracy is close to 100%. Any problems which I have seen can be attributed to user error, for instance using a large focus box which overlaps the subject onto the background.

In general Canon’s dual pixel AF system has proven to be the best and most reliable I have ever used.

For  macro work AF slows a bit due to the amount of glass being pushed back and forth over a centimeter or more of  travel.

At normal focus distances of a meter or more and using Servo AF on the R5 the lens can follow focus on moving subjects quite easily even in low light.

With moving subjects close up such as flowers waving in the breeze, the technique of setting HI+drive and AF Servo does not work as well as it can  when the RF 100mm f2.8 L macro or RF 24-105mm f4L lenses are mounted.

Manual focus is very easy to use on the R5 aided by Canon’s swinging arms focus guide. An analogue focus distance scale can be displayed but unfortunately it favours the closest distances. At normal distances all we get are marks for  0.5m, 1.0m and infinity.

Close-up/Macro

Macro lenses have traditionally used the 90-100mm focal length with the occasional 50mm and 200mm for variety.

So a 35mm lens billed as macro is something of a novelty. However it appears to be one of the selling points for several of the new RF lenses, both primes and zooms. Even the RF 16mm f2.8 is billed as macro.

As it happens I make frequent use of the close-up capability of the RF 35mm f1.8 and find it to be rather effective for the flowers which I often photograph. Pictures are sharp with good detail out to the periphery even at minimum focus distance.

The maximum magnification of 0.5x life size on the sensor is sufficient for many requirements. In fact in the real world depth of field at full lifesize is so shallow that many little subjects cannot be rendered sharp throughout.

I generally use f16 for close-ups but f22 can also give good results with a bit more depth of field. 

Sharpness/resolution

Right from f1.8 sharpness and resolution are very high right across the frame. On my copy one corner is a little soft at f1.8. This cleans up as the aperture is reduced through f2 and f2.8.

On pixel peeping I can see  the best aperture range is around f4-f8 but really this lens can be used with confidence at any aperture from f1.8-f16.

This is an excellent result for any lens at any price point but especially for one priced at an entry/enthusiast level.

Peripheral shading is very obvious at f1.8, reducing to insignificant by around f4. This is easily corrected in camera with JPGs and in the Raw converter with Raw files as long as a lens profile is available.

Mild barrel distortion  is present in uncorrected Raw files but is easily corrected.

Various kinds of  flaresincluding veiling and colored shapes can be induced by deliberately pointing the lens at a bright light source such as the sun.  But I frequently use this lens in bright sun and find that with a few simple precautions such as keeping hard light off the front element that flares have not been a problem.

I have found the Bokeh or out of focus rendition pleasantly smooth without objectionable characteristics such as nisen (double line).

Color fringing is a minor issue, seen most often with foliage against a hot sky at the periphery of the frame. This is corrected in camera with JPGs and easily corrected in Adobe Camera Raw with the sliders or better, the eyedropper tool in the Optics tab.

Overall imaging integrity across the frame is very high in all circumstances making this a very versatile and desirable lens for any owner of an RF mount camera.

I have experienced no problems with reliability over my 2 year time with the lens.

Although it is not listed as weather or dust sealed I have not seen any dust or dirt in the glass.

Three dimensional distribution of sharpness

This is a very important characteristic which most lens testers have unfortunately not included in their test schedules.

The actual test is very easy to do. You can read about it here. 

This tells us what happens to the distribution of sharpness as the aperture is closed down.

The characteristic behaviour of lenses in this regard is far from simple or predictable, particularly in the case of wide angle optics.

Some lens reviewers talk about “focus shift” with aperture change. The distribution of sharpness does indeed change with aperture but not in any simple fashion.

Understanding the complex nature of the change can be important for obtaining optimal sharpness across the frame especially for landscape type subjects when we often want everything rendered sharply.

Note that Canon lenses focus with the aperture wide open.

You can see that at f2 the zone of greatest sharpness is just slightly behind the stick on which I focussed.

F2

At f4 the zone of greatest sharpness in the center of the frame has moved back slightly. If one only looked at the frame center one might conclude that there has been rearward focus shift. But the remainder of the frame shows that what actually happens is considerably more complex. The zone of greatest sharpness has moved forward in the outer section of the frame then back again right at the edges, producing a moustache shaped sharpness distribution.

F4

By f8 sharpness has spread further in both directions but is distributed more towards the camera than away from the camera. 

F8

For optimum sharpness across the frame with a landscape type subject I focus slightly above (further away than ) the part of the subject under the center of the frame in the viewfinder.

The experience of single prime lens photography

In the good ol’ days of film, way back in the 20^thCentury, I used prime lenses because that is all there was. In fact I used a 50mm or 55m lens because wide angle lenses of the time were not very good optically.

Then came the zoom era and for many years I used zooms most of the time.

But I also like working with primes

Since acquiring the Canon EOS R5 I have been increasingly drawn to primes in part due to the remarkable image quality which can be produced.

The other appeal of primes is that they can be compact and unobtrusive yet still deliver excellent quality.

Favoured focal lengths for primes have included 28, 35, 40 and 50mm, each having its advocates. I have used each of these over the years and found each can work well depending on the photographer’s preferred style of engaging with their visual environment.

Photographers who like to get in close to their subject might prefer 28mm. Those who like to keep a bit more distance will likely select the 50mm.

Where does that leave the 35mm ?  For some it is neither fish nor fowl. For others it is the one focal length which  with judicious use of the “two foot zoom” can cover  (almost) all eventualities.

After two years I am inclined towards the latter position. I really like working with the perspective and subject distance given by the 50mm but if I want to go forth with just one lens (as is often the case) I will mount the 35mm for its greater versatility.

Full frame vs crop sensor

In a previous post I put the view that crop sensor interchangeable lens cameras do not appear to have bright future.

My reasoning for this is that the crop sensor numbers don’t make sense to me.

Look at the little table below. I compare the RF 35mm f1.8 with the nearest two Micro Four Thirds equivalents from Olympus.

In MFT we can have the larger 17mm f1.2 which is twice the price and three times the mass while still not delivering an equivalent f number.

Or we can opt for the 17mm f1.8 which is smaller, lighter and a bit less expensive but with an aperture two stops smaller.

Summary

The  RF 35mm f1.8 lens slipped in somewhat under the radar when it was introduced in 2018. There was much fanfare about the RF 28-70mm f2 and RF 50mm f1.2 lenses along with commentary about the new lens mount and then many complaints about the original EOS R body. So the RF 35mm f1.8 received little attention either positive or negative.

Even user forums often seem to be less interested in the 1.8 lens than a range of hoped-for options of more exotic specification. I guess that is the nature of enthusiast forums.

However I have found the RF 35mm f1.8 to be one of the best and most versatile prime lenses I have ever used. What it lacks in bling it gains in real world capability.

The only negative which I have seen reported is the noise of the focus motor which is audible in a quiet room when racking focus from close-up to normal distance but is barely detectable when focussing from 1-5 meters.

Alternatives

At this stage in the evolution of the Canon RF mount alternatives are limited.

The EF 35mm f2 IS USM appears to be still available but at AUD1035 is considerably more expensive than the newer RF lens. It is also larger and heavier and for use on an RF mount camera requires the adapter thereby increasing size and weight even further.

The EF 35mm f1.4 L (11) IS  appears to be still available but it is much larger and heavier and four times the price and it requires the adapter and after all that you get a 0.66 stop advantage. That’s a heck of a price for a small aperture advantage.

There are also EF mount 35mm lenses from Samyang and Tamron and probably others. But I would be wary of these third party offerings especially on an RF mount body with no guarantee they will focus correctly.

The competition

Each of the full frame mirrorless brands offers a 35mm f1.8. Here is a table comparing their main specs. The price given is for new, retail, GST paid, from the same vendor on the same day in AUD. For the just announced Panasonic   I derived an estimate of the approximate Australian price from that listed on  Amazon USA.

You can see the Canon RF is the smallest and  least expensive yet has the best specification list with a stabiliser and 0.5x half life size magnification.

Nikon Z users might not be too happy. The Z lens is the largest, heaviest and most expensive yet has no stabiliser and the lowest maximum magnification.

I checked out several reviews of the Canon, Sony and Nikon lenses and found nothing to suggest that the Canon is inferior to the others in any substantive way.

Loads of detail when you want it