Sunday, September 21, 2025
Saturday, September 20, 2025
Monday, September 15, 2025
Canon RF 135mm f/1.8 L IS USM Review
Canon RF 135mm f/1.8 L IS USM Review
“The Canon RF 135mm f/1.8 L IS USM is a professional-grade lens with excellent build quality, featuring weather sealing and a customizable control ring. It boasts outstanding sharpness, low chromatic aberrations, and minimal distortion, though it exhibits high vignetting at maximum aperture. The lens’s autofocus is fast and silent, and its image stabilizer provides a significant gain, making it a strong choice for low-light photography.
So while we are at reviewing 135mm lenses, let’s not forget about this one – the Canon RF 135mm f/1.8 L IS USM. It is also interesting because it’s the only lens in its class featuring an image stabilizer. As such, it deserves to be a little more expensive than other lenses. In the US, it’s still “comparatively affordable” at around $2100 USD (probably not tariff-adjusted yet), whereas in other markets it’s bizarrely expensive. In Australia, it is almost 50% more expensive than the Sony FE 135mm f/1.8 GM. Anyway …
Coming back to the lens itself, the build quality is in line with what we have seen with other (black-colored) professional-grade RF lenses. The lens body is made of Canon’s engineered plastics, which you may or may not like – the finish is a bit too slippery in our book. However, it’s certainly sturdy and, of course, sealed against the elements. The focus ring turns smoothly, and there’s the usual customizable control ring at the front of the lens. A barrel-shaped lens hood is provided.
The AF is based on Canon’s Nano USM, which is both very snappy and silent. The image stabilizer is good for a gain of 5 to 8 f-stops (claimed), depending on whether your camera features an IBIS. As usual, take the statement with a grain of salt during real-life shooting, but it’s close depending on your coffee intake.
| Specifications | |
|---|---|
| Optical construction | 17 elements in 12 groups (3x UD) |
| Number of aperture blades | 9 (rounded) |
| min. focus distance | 0.7m (max magnification 0.26x) |
| Dimensions | φ89.2 x 130.3 mm |
| Weight | 935g |
| Filter size | φ82mm |
| Hood | barrel-shaped (bayonet mount, supplied) |
| Other features | image stabilizer (5 to 8 f-stop claimed efficiency depending on camera) weather-sealing control ring focus stop button fluorine coating |
Distortions
The Canon RF 135mm f/1.8 L IS produces a slight amount of pincushion distortion in RAW images, and the remaining traces are removed via auto-correction if activated.
Vignetting
Ultra-large aperture lenses tend to produce very high vignetting at max aperture. This also applies to the Canon lens with a light falloff of more than 2 EV (f-stops) in RAW images – somewhat higher than average in this class. The original vignetting is almost gone from f/5.6.
The profile correction reduces this to a negligible degree even straight from the maximum aperture.
MTF (resolution) at 45 megapixels
The Canon lens delivered an outstanding resolution performance in the lab across all relevant aperture settings and across the image field. Stopping down improves the quality only marginally. This is probably the best result that we have seen from any tested lens so far.
The field curvature is negligible. The centering quality of the tested sample was very good.
Please note that the MTF results are not directly comparable across the different systems!
Below is a simplified summary of the formal findings. The chart shows line widths per picture height (LW/PH) which can be taken as a measure of sharpness. If you would like to know more about the MTF50 figures, you may check out the corresponding Imatest Explanations.
Chromatic Aberrations (CAs)
Lateral CAs have an average width of less than 0.5px at the image borders. This is negligible, even without auto-correction.
Bokeh
A 135mm f/1.8 lens is primarily about shallow depth-of-field photography, so let’s take a look at the quality of the bokeh.
Out-of-focus highlights are nicely rendered with a very smooth inner zone of the discs and barely any outlining effect. The circular shape of the discs remains intact even at f/4.
When looking at the highlight rendering across the whole image field, we can spot the usual “cat-eye” deterioration from roughly the mid-field into the corners. As usual, stopping down will broaden the zone showing circular discs, and the corner discs are restored at f/4.
The rendering quality in the focus transition zone is a bit surprising. The background blur – shown to the left below – looks rather nervous. We have seen smoother results from other 135mm f/1.8 lenses here. The usually less important foreground blur is pretty smooth, though.
Just to illustrate this in a real-life scene (the image is also available from the download section), check the background blur in the scene below – this doesn’t look ideal with some strangely hard edges in the background blur. And this isn’t an overly difficult scene.
Bokeh Fringing / LoCA
LoCAs, or bokeh fringing, is a color fringing effect on the Z-axis. It shows up with a purplish tint in front of the focus point and a greenish tint behind – and it’s nearly impossible to fully correct in post. The Canon RF 135mm f/1.8 L IS USM does a very good job in this respect. There are only slight traces of fringing visible at f/1.8.
You may also notice that the focus point remains spot-on when stopping down (= no relevant RSAs).
Sample Images
9.0
The Canon RF 135mm f/1.8 L IS USM is one of the sharpest - if not the sharpest - lens that we've ever tested. It's brutally sharp at all relevant settings, and that's across the frame. Lateral and axial CAs are very low, and image distortions aren't relevant either, with only marginal auto-correction needed here. The RAW vignetting is comparatively high at f/1.8, although, once again, auto-correction will come to the rescue here. A curious flaw is the "technical bokeh" in the focus transition zone. To be fair here, you will usually use the lens for very shallow depth-of-field photography where this won't be noticed anyway. However, it can be noticed in certain scenes.
The build quality is great, as you can expect from a Canon L lens. It feels, and is, sturdy despite the use of engineered plastics. The AF is very fast, as with all Canon USM lenses. The image stabilizer is a unique value-add for such a lens. Optical IS is more efficient at long focal lengths, and combined with IBIS, it can give you an edge when shooting in darker places.
Overall, Canon delivered an impressive piece of engineering here.
PS: A special callout to the friendly folks from Rent-A-Cam who gave us a little discount when renting the lens. If you live in Sydney/Australia, you may wish to check them out, and don't hesitate to send our greetings.
Optical Quality 9
Mechanical Quality 10
Price / Performance (depends on where you live) 8”
Friday, September 12, 2025
A Once-In-A-Lifetime Green Comet May Soon Be Visible, Scientists Say
A Once-In-A-Lifetime Green Comet May Soon Be Visible, Scientists Say
“After a quiet 2025 for comets, skywatchers may soon get a very special naked-eye spectacle in the shape of Comet Lemmon (C/2025 A6). Discovered in January, the green comet has brightened faster than predicted in recent weeks and now looks set to be visible from dark rural skies during October 2025. It could be at its brightest during the peak of the annual Orionid meteor shower.
The comet was discovered on August 12, 2023 by Hideo Nishimura during 30-second exposures with a standard digital camera. Taken in Nerja, Málaga. Andalusia. South of Spain.
Key Facts
Comet Lemmon was discovered on Jan. 3, 2025, by the Mount Lemmon Survey in Arizona. It was initially thought to be an asteroid.
It last visited the inner solar system 1,396 years ago — in the seventh century — with astronomers calculating that it will return in the year 3421, making it a once-in-a-lifetime comet.
By mid-October, it will be close to the Big Dipper in the northern night sky. It could shine as brightly as 5th magnitude, making it visible to the naked eye from dark rural skies.
Since Comet Lemmon will be visible in a part of the northern sky that's circumpolar, it will be visible in both morning and evening skies by mid-to-late October as seen from the Northern Hemisphere.
It will get closest to Earth — and, therefore, shine brightest — on Oct. 21, getting closest to the sun on Nov. 8. Comet Lemmon may be visible during that entire time.
How Bright Will Comet Lemmon Get?
Forecasts for Comet Lemmon’s brightness have recently changed dramatically. Early predictions placed it at around 10th magnitude in October, but according to Bob King at Sky & Telescope, recent observations suggest it could peak at magnitude 4.5 around Oct. 21 — visible to the naked eye from dark skies and easy in binoculars. However, comets behave erratically and it could become brighter or fainter than currently predicted.
During its closest pass to Earth, it will be at a distance of 56 million miles from Earth — the equivalent of about 60% of the distance between Earth and the sun.
A Comet, ‘shooting Stars’ And Aurora?
If Comet Lemmon brightens, it's sure to be widely observed by skywatchers in the Northern Hemisphere. Its closest approach to Earth on Oct. 21 coincides not only with a new moon, but also with the peak of the Orionid meteor shower, when about 20 "shooting stars" per hour are expected. October is also a peak month for displays of the Northern Lights; if geomagnetic activity is high, some observers at northern latitudes may also see the comet amid auroras. It will be a fast-moving comet, so its position in the night sky will change dramatically from night to night.“
Thursday, September 11, 2025
Wednesday, September 10, 2025
Tuesday, September 09, 2025
Friday, September 05, 2025
Tuesday, September 02, 2025
Opinion | The One Danger That Should Unite the U.S. and China
Opinion | The One Danger That Should Unite the U.S. and China
Illustration by Saratta Chuengsatiansup
“China and America don’t know it yet, but the artificial intelligence revolution is going to drive them closer together, not farther apart. The rise of A.I. will force them to fiercely compete for dominance and — at the same time and with equal energy — cooperate at a depth our two countries have never attempted before. They will have no choice.
Why am I so confident about that? Because A.I. has certain unique attributes and poses certain challenges that are different from those presented by any previous technology. This column will discuss them in detail, but here are a couple to chew on for starters: A.I. will spread like a steam vapor and seep into everything. It will be in your watch, your toaster, your car, your computer, your glasses and your pacemaker — always connected, always communicating, always collecting data to improve performance. As it does, it will change everything about everything — including geopolitics and trade between the world’s two A.I. superpowers, and the need for cooperation will become ever more apparent each month.
For instance, say you break your hip, and your orthopedist tells you the world’s most highly rated hip replacement is a Chinese-made prosthetic that is infused with Chinese-designed A.I. It is constantly learning about your body and, with its proprietary algorithm, using that data to optimize your movements in real time. It’s the best!
Would you let that “smart hip” be sewn into you? I wouldn’t — not unless I knew that China and America had agreed to embed a common ethical architecture into every A.I.-enabled device that either nation builds. Viewed on a much larger, global scale, this could ensure that A.I. is used only for the benefit of humanity, whether it is employed by humans or operates on its own initiative.
At the same time, Washington and Beijing will soon discover that putting A.I. in the hands of every person and robot on the planet will super-empower bad people to levels no law enforcement agency has ever faced. Remember: Bad guys are always early adopters! And without the United States and China agreeing on a trust architecture to ensure that every A.I. device can be used only for humans’ well-being, the artificial intelligence revolution is certain to produce super-empowered thieves, scam artists, hackers, drug dealers, terrorists and misinformation warriors. They will destabilize both America and China, long before these two superpower nations get around to fighting a war with each other.
In short, as I will argue, if we cannot trust A.I.-infused products from China and it can’t trust ours, very soon the only item China will dare buy from America will be soybeans and the only thing we will dare buy from China is soy sauce, which will surely sap global growth.
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Monday, September 01, 2025
Voyager 1 ‘intercepts’ a song in the space — It came from 25 billion km away
Voyager 1 ‘intercepts’ a song in the space — It came from 25 billion km away
“Voyager 1, a NASA probe launched in 1977, intercepted a message from 25 billion kilometers away. The European Space Agency (ESA) transmitted a live performance of Johann Strauss II’s “The Blue Danube” to celebrate its 50th anniversary and Strauss’s 200th birthday. The mission aimed to showcase Voyager 1’s enduring legacy and the universal language of music.
Have you ever thought about hearing a song coming directly from space? Well, that’s what happened last Saturday in May, when the Voyager 1 probe intercepted a message that came from 25 billion kilometers away from Earth. Many thought it was some kind of operational command or even a historical novelty, but reality surprised everyone when scientists came across a song.
Do you happen to know Voyager 1?
Before we can decipher what this music was that was intercepted and if it had any meaning, we need to look at the object that made all this possible: Voyager 1. Back in 1977, NASA designed this probe with the aim of studying other planets in the Solar System – and beyond. And it did so successfully, you see?
First, it managed to fly over Jupiter and Saturn, until it passed what experts call the heliosphere, which is nothing more than the region of influence of our Sun, and then it ventured into interstellar space. Today it is already very far from us, we are talking about 24.8 billion kilometers from Earth, that is more than 166 times the distance between the Earth and the Sun. It is worth remembering that no other object created by us is further away.
All this distance becomes a challenge for sending messages back and forth. Just to give you an idea, any radio signal sent from us here on Earth to there takes about 23 hours to reach it. Of course, in addition to all this distance, Voyager 1 is already old, operates with limited systems and an antenna of only 3.7 meters, but it remains firm in its mission of receiving and sending signals. It was with this in mind (and through it) that ESA decided to do something special, and that is where music comes into play.
The song that traveled 25 km away from Earth
You might be wondering: what does ESA have to do with this intergalactic music thing? Well, it wanted to pay tribute… That’s because on June 1st, the agency turns 50 and, along with that, it also turns 200 years since the birth of composer Johann Strauss II. In other words, they combined business with pleasure and transmitted a live performance by the Vienna Symphony Orchestra directly into space — and of course, the probe responsible for this was Voyager 1 (this after it had returned to service after almost 20 years).
And what was the song? It was the waltz, The Blue Danube (An der schönen blauen Donau), composed by Strauss in 1866. If you don’t know it, it’s worth mentioning that this song became very famous for representing space. Another interesting fact is that this became even more established after being used in the film 2001: A Space Odyssey, by Stanley Kubrick.
The song that became a message to the unknown
What many people wondered was the reason for this space signal tribute, because, let’s face it, it’s not something that happens every day, so the authors of the project even explained (after joking that this was used to make aliens dance):
“The beauty of this mission lies in its boundless imagination and optimism. Music is a universal language – transcending borders, species and even galaxies. If there are life forms out there, perhaps they sense the joy, elegance and rhythm of humanity itself, and perhaps they respond with a dance of their own”
Apart from that, it also served to show how Voyager 1, even at almost 50 years old (47 to be more exact), navigating through a solitary environment, continues to inspire many people – even after “waking up” after almost two decades,”