Subject Isolation on the Beach: Canon RF 135mm f/1.8 vs EF 135mm f/2
This beach frame is a good argument for the 135mm focal length. The woman sitting on the sand holds the eye because she’s the only thing rendered with any real detail. Everything behind her turns into a wash of turquoise and green: umbrellas, chairs, sunbathers, a whole crowded stretch of coastline reduced to shapes and patches of colour. Nothing back there competes with her, and nothing back there had to be moved, cropped out or waited for.
Most of that work isn’t the aperture. It’s the compression. At 135mm the umbrellas sit big in the frame even though they’re a long way behind her, so instead of clutter you get a backdrop that fills the space edge to edge. The turquoise umbrella just above her head does the rest, because a cool colour against warm sand and warm skin separates a subject about as reliably as depth of field does.
What a third of a stop actually buys
The scene made me want to put the Canon RF 135mm f/1.8L IS USM next to the old EF 135mm f/2L USM, and the first thing worth clearing up is the size of the gap. Going from f/2 to f/1.8 isn’t a stop. It’s about a third of one.
Run the depth of field at a realistic distance for this kind of shot, say five metres, and the difference is close to invisible: roughly 16cm of acceptable focus at f/2 against roughly 15cm at f/1.8. A centimetre. You will not see it in a print and you probably won’t see it at 100%.
The blur behind the subject is a slightly better argument. Background blur scales with the physical size of the entrance pupil, and 135mm at f/1.8 gives you 75mm of aperture against 67.5mm at f/2. That’s about 11% larger blur circles. Real, measurable, and still not the reason to choose one of these lenses over the other.
Where the RF lens earns its price
The honest case for the RF is everything that isn’t the f-number. Stabilisation, for a start, which matters not at all on a bright beach at 1/1000 and matters a great deal at dusk on the same promenade three hours later. Then the autofocus, which is the real gap. The EF is a 1996 design with ring USM, and it focuses perfectly well, but it was never built to be dragged around by eye detection on a subject who’s moving. The RF was. For candids at 135mm, where your depth of field is a few centimetres and the eye is the only thing that can be sharp, that’s worth more than any bokeh comparison.
The EF answers on size, price and the fact that it still renders beautifully. It’s around 750g against roughly 935g, shorter, narrower, takes 72mm filters instead of 82mm, and used copies sell for a fraction of what the RF costs new. It fringes a little wide open on high-contrast edges. It has been the sentimental favourite portrait lens on Canon bodies for thirty years for a reason.
I shoot RF bodies with an EF adapter and a couple of old EF primes already, so the EF 135 is the version that’s realistically sitting in my basket. On the R8 it’s a straightforward 135mm. On the R100 the crop turns it into a 216mm equivalent, which is a free extra reach on exactly this kind of beach scene, at the cost of needing to stand further back than is always polite.
Why the focal length keeps earning its place
Busy backgrounds are the normal condition for beach portraits, street work and candids. You rarely get to choose what’s behind someone. 135mm lets you choose how much of it registers, from three or four metres away, without standing on top of your subject.
And the goal was never to erase the background. In this frame the umbrellas are still doing something. They tell you where you are, they set the colour, they give the woman something to sit against. They just stopped asking to be looked at.
That’s the whole trick. Turn the background into light and colour and let it stay there.