Martin Krzywinski / Canada's Michael Smith Genome Sciences Centre / mkweb.bcgsc.ca Martin Krzywinski / Canada's Michael Smith Genome Sciences Centre / mkweb.bcgsc.ca - contact me Martin Krzywinski / Canada's Michael Smith Genome Sciences Centre / mkweb.bcgsc.ca on Twitter Martin Krzywinski / Canada's Michael Smith Genome Sciences Centre / mkweb.bcgsc.ca - Lumondo Photography Martin Krzywinski / Canada's Michael Smith Genome Sciences Centre / mkweb.bcgsc.ca - Pi Art Martin Krzywinski / Canada's Michael Smith Genome Sciences Centre / mkweb.bcgsc.ca - Hilbertonians - Creatures on the Hilbert CurveMartin Krzywinski / Canada's Michael Smith Genome Sciences Centre / mkweb.bcgsc.ca - Pi Day 2020 - Piku
Poetry is just the evidence of life. If your life is burning well, poetry is just the ashLeonard Cohenburn somethingmore quotes

Martin Krzywinski / Canada's Michael Smith Genome Sciences Centre / mkweb.bcgsc.ca

The Outbreak Poems — artistic emissions in a pandemic


fun + amusement

Canon EF Lenses - f/ vs focal length chart mkweb :: on flickr :: contact

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.

VIEW ALL

news + thoughts

Virus Mutations Reveal How COVID-19 Really Spread

Mon 04-05-2020

Genetic sequences of the coronavirus tell story of when the virus arrived in each country and where it came from.

Our graphic in Scientific American's Graphic Science section in the June 2020 issue shows a phylogenetic tree based on a snapshot of the data model from Nextstrain as of 31 March 2020.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Virus Mutations Reveal How COVID-19 Really Spread. Text by Mark Fischetti (Senior Editor), art direction by Jen Christiansen (Senior Graphics Editor), source: Nextstrain (enabled by data from GISAID).

Cover of Nature Cancer April 2020

Mon 27-04-2020

Our design on the cover of Nature Cancer's April 2020 issue shows mutation spectra of patients from the POG570 cohort of 570 individuals with advanced metastatic cancer.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Each ellipse system represents the mutation spectrum of an individual patient. Individual ellipses in the system correspond to the number of base changes in a given class and are layered by mutation count. Ellipse angle is controlled by the proportion of mutations in a class within the sample and its size is determined by a sigmoid mapping of mutation count scaled within the layer. The opacity of each system represents the duration since the diagnosis of advanced disease. (read more)

The cover design accompanies our report in the issue Pleasance, E., Titmuss, E., Williamson, L. et al. (2020) Pan-cancer analysis of advanced patient tumors reveals interactions between therapy and genomic landscapes. Nat Cancer 1:452–468.

Modeling infectious epidemics

Wed 06-05-2020

Every day sadder and sadder news of its increase. In the City died this week 7496; and of them, 6102 of the plague. But it is feared that the true number of the dead this week is near 10,000 ....
—Samuel Pepys, 1665

This month, we begin a series of columns on epidemiological models. We start with the basic SIR model, which models the spread of an infection between three groups in a population: susceptible, infected and recovered.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Nature Methods Points of Significance column: Modeling infectious epidemics. (read)

We discuss conditions under which an outbreak occurs, estimates of spread characteristics and the effects that mitigation can play on disease trajectories. We show the trends that arise when "flattenting the curve" by decreasing `R_0`.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Nature Methods Points of Significance column: Modeling infectious epidemics. (read)

This column has an interactive supplemental component that allows you to explore how the model curves change with parameters such as infectious period, basic reproduction number and vaccination level.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Nature Methods Points of Significance column: Modeling infectious epidemics. (Interactive supplemental materials)

Bjørnstad, O.N., Shea, K., Krzywinski, M. & Altman, N. (2020) Points of significance: Modeling infectious epidemics. Nature Methods 17:455–456.

The Outbreak Poems

Sat 04-04-2020

I'm writing poetry daily to put my feelings into words more often during the COVID-19 outbreak.

That moment
when
you know a moment.
Branch to branch,
flit,
look everywhere,
chirp.
Memory,
scent
of thought fleeting.
Distant pasts
all
ways in plural
form.

Read the poems and learn what a piku is.

Deadly Genomes: Genome Structure and Size of Harmful Bacteria and Viruses

Tue 17-03-2020

A poster full of epidemiological worry and statistics. Now updated with the genome of SARS-CoV-2 and COVID-19 case statistics as of 3 March 2020.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Deadly Genomes: Genome Structure and Size of Harmful Bacteria and Viruses (zoom)

Bacterial and viral genomes of various diseases are drawn as paths with color encoding local GC content and curvature encoding local repeat content. Position of the genome encodes prevalence and mortality rate.

The deadly genomes collection has been updated with a posters of the genomes of SARS-CoV-2, the novel coronavirus that causes COVID-19.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Genomes of 56 SARS-CoV-2 coronaviruses that causes COVID-19.
Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Ball of 56 SARS-CoV-2 coronaviruses that causes COVID-19.
Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
The first SARS-CoV-2 genome (MT019529) to be sequenced appears first on the poster.

Using Circos in Galaxy Australia Workshop

Wed 04-03-2020

A workshop in using the Circos Galaxy wrapper by Hiltemann and Rasche. Event organized by Australian Biocommons.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Using Circos in Galaxy Australia workshop. (zoom)

Download workshop slides.

Galaxy wrapper training materials, Saskia Hiltemann, Helena Rasche, 2020 Visualisation with Circos (Galaxy Training Materials).



me as a keyword list

aikido | analogies | animals | astronomy | comfortable silence | cosmology | dorothy parker | drumming | espresso | fundamental forces | good kerning | graphic design | humanism | humour | jean michel jarre | kayaking | latin | little fluffy clouds | lord of the rings | mathematics | negative space | nuance | perceptual color palettes | philosophy of science | photography | physical constants | physics | poetry | pon farr | reason | rhythm | richard feynman | science | secularism | swing | symmetry and its breaking | technology | things that make me go hmmm | typography | unix | victoria arduino | wine | words