Canon EF Lenses
the chart
Each prime lens on the chart is represented by a point given by the lens' focal length (mm) and maximum aperture. Zoom lenses are shown as curves whose end points correspond to the lens' maximum aperature at its lowest and highest focal lengths. The path of the curve does not reflect the relationship between focal length and maximum aperture - the curve is routed to minimize, where possible, the number of intersection with other curves. Prices are based on listings at adorama.com.
lens information
Don't be surprised if the information in the pages below isn't updated frequently. Lens technology is improved incrementally and new lens launches are infrequent.
- Canon offers a lot of information about their lenses. A lot of it is very readable, regardless of level and knowledge of the Canon line up. An EF Lens 101 covers the basics. Canon offers an individual summary for each of its EF lenses, which includes sample images and MTF. A complete EF lens spec sheet is also available (local copy).
- Canon publishes the modulation transfer function profiles (wtf is mtf?) for all EF lenses. This is a good thing. The MTF profiles are computed, however, not based on real performance. To compare two MTF functions try Andrew's Magnificent MTF Comparometer.
- An excellent EF Lens Beginner's FAQ is provided by NK Guy. This section of the FAQ is part of a larger EOS Beginner's FAQ. Even if you are a seasoned pro, I highly recommend this resource.
- Finally, if you want to know everything about EF lenses from the horse's mouth, pick up a copy of Canon EF Lens Works III. It's a Canon publication, thus shamelessly self-contratulatory and at times extremely poorly written and downright cheesy, but it does provide (a) description of every lens, (b) sample images for each lens, some breathtaking, (c) MTF functions, including with 1.4x and 2x extenders, (d) description of Canon technology and (e) pretty comprehensive optical glossary. At $20 is a very good buy.
lens reviews
- fredmiranda.com publishes user reviews of Canon, as well as other, lenses. Good reading if you want to know what a lot of people who use the lenses actually think.
- Reviews by William L Castleman of a large number of L lenses. The reviews are well written, and of a technical nature, making use of images of mannequins to illustrate lens characteristics and resolution plots.
- Bob Atkins reviews not only Canon but also some Tamron lenses.
- A large number of reviews at The Digital Picture. A lot of the reviews of similar lenses use the same text and are heavy on describing features more than performance.
Happy 2025 π Day—
TTCAGT: a sequence of digits
Celebrate π Day (March 14th) and sequence digits like its 1999. Let's call some peaks.
Crafting 10 Years of Statistics Explanations: Points of Significance
I don’t have good luck in the match points. —Rafael Nadal, Spanish tennis player
Points of Significance is an ongoing series of short articles about statistics in Nature Methods that started in 2013. Its aim is to provide clear explanations of essential concepts in statistics for a nonspecialist audience. The articles favor heuristic explanations and make extensive use of simulated examples and graphical explanations, while maintaining mathematical rigor.
Topics range from basic, but often misunderstood, such as uncertainty and P-values, to relatively advanced, but often neglected, such as the error-in-variables problem and the curse of dimensionality. More recent articles have focused on timely topics such as modeling of epidemics, machine learning, and neural networks.
In this article, we discuss the evolution of topics and details behind some of the story arcs, our approach to crafting statistical explanations and narratives, and our use of figures and numerical simulations as props for building understanding.
Altman, N. & Krzywinski, M. (2025) Crafting 10 Years of Statistics Explanations: Points of Significance. Annual Review of Statistics and Its Application 12:69–87.
Propensity score matching
I don’t have good luck in the match points. —Rafael Nadal, Spanish tennis player
In many experimental designs, we need to keep in mind the possibility of confounding variables, which may give rise to bias in the estimate of the treatment effect.
If the control and experimental groups aren't matched (or, roughly, similar enough), this bias can arise.
Sometimes this can be dealt with by randomizing, which on average can balance this effect out. When randomization is not possible, propensity score matching is an excellent strategy to match control and experimental groups.
Kurz, C.F., Krzywinski, M. & Altman, N. (2024) Points of significance: Propensity score matching. Nat. Methods 21:1770–1772.
Understanding p-values and significance
P-values combined with estimates of effect size are used to assess the importance of experimental results. However, their interpretation can be invalidated by selection bias when testing multiple hypotheses, fitting multiple models or even informally selecting results that seem interesting after observing the data.
We offer an introduction to principled uses of p-values (targeted at the non-specialist) and identify questionable practices to be avoided.
Altman, N. & Krzywinski, M. (2024) Understanding p-values and significance. Laboratory Animals 58:443–446.
Depicting variability and uncertainty using intervals and error bars
Variability is inherent in most biological systems due to differences among members of the population. Two types of variation are commonly observed in studies: differences among samples and the “error” in estimating a population parameter (e.g. mean) from a sample. While these concepts are fundamentally very different, the associated variation is often expressed using similar notation—an interval that represents a range of values with a lower and upper bound.
In this article we discuss how common intervals are used (and misused).
Altman, N. & Krzywinski, M. (2024) Depicting variability and uncertainty using intervals and error bars. Laboratory Animals 58:453–456.
Nasa to send our human genome discs to the Moon
We'd like to say a ‘cosmic hello’: mathematics, culture, palaeontology, art and science, and ... human genomes.
