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
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information: curious



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

Points of Significance celebrates 50th column

Mon 24-08-2020

We are celebrating the publication of our 50th column!

To all our coauthors — thank you and see you in the next column!

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Nature Methods Points of Significance: Celebrating 50 columns of clear explanations of statistics. (read)

Uncertainty and the management of epidemics

Mon 24-08-2020

When modelling epidemics, some uncertainties matter more than others.

Public health policy is always hampered by uncertainty. During a novel outbreak, nearly everything will be uncertain: the mode of transmission, the duration and population variability of latency, infection and protective immunity and, critically, whether the outbreak will fade out or turn into a major epidemic.

The uncertainty may be structural (which model?), parametric (what is `R_0`?), and/or operational (how well do masks work?).

This month, we continue our exploration of epidemiological models and look at how uncertainty affects forecasts of disease dynamics and optimization of intervention strategies.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Nature Methods Points of Significance column: Uncertainty and the management of epidemics. (read)

We show how the impact of the uncertainty on any choice in strategy can be expressed using the Expected Value of Perfect Information (EVPI), which is the potential improvement in outcomes that could be obtained if the uncertainty is resolved before making a decision on the intervention strategy. In other words, by how much could we potentially increase effectiveness of our choice (e.g. lowering total disease burden) if we knew which model best reflects reality?

This column has an interactive supplemental component (download code) that allows you to explore the impact of uncertainty in `R_0` and immunity duration on timing and size of epidemic waves and the total burden of the outbreak and calculate EVPI for various outbreak models and scenarios.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Nature Methods Points of Significance column: Uncertainty and the management of epidemics. (Interactive supplemental materials)

Bjørnstad, O.N., Shea, K., Krzywinski, M. & Altman, N. (2020) Points of significance: Uncertainty and the management of epidemics. Nature Methods 17.

Background reading

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

Bjørnstad, O.N., Shea, K., Krzywinski, M. & Altman, N. (2020) Points of significance: The SEIRS model for infectious disease dynamics. Nature Methods 17:557–558.

Cover of Nature Genetics August 2020

Mon 03-08-2020

Our design on the cover of Nature Genetics's August 2020 issue is “Dichotomy of Chromatin in Color” . Thanks to Dr. Andy Mungall for suggesting this terrific title.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Dichotomy of Chromatin in Color. Nature Genetics, August 2020 issue. (read more)

The cover design accompanies our report in the issue Gagliardi, A., Porter, V.L., Zong, Z. et al. (2020) Analysis of Ugandan cervical carcinomas identifies human papillomavirus clade–specific epigenome and transcriptome landscapes. Nature Genetics 52:800–810.

Poster Design Guidelines

Wed 15-07-2020

Clear, concise, legible and compelling.

The PDF template is a poster about making posters. It provides design, typography and data visualiation tips with minimum fuss. Follow its advice until you have developed enough design sobriety and experience to know when to go your own way.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Poster Design Guidelines — Clear, concise, legible and compelling..

The SEIRS model for infectious disease dynamics

Thu 18-06-2020

Realistic models of epidemics account for latency, loss of immunity, births and deaths.

We continue with our discussion about epidemic models and show how births, deaths and loss of immunity can create epidemic waves—a periodic fluctuation in the fraction of population that is infected.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Nature Methods Points of Significance column: The SEIRS model for infectious disease dynamics. (read)

This column has an interactive supplemental component (download code) that allows you to explore epidemic waves and introduces the idea of the phase plane, a compact way to understand the evolution of an epidemic over its entire course.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Nature Methods Points of Significance column: The SEIRS model for infectious disease dynamics. (Interactive supplemental materials)

Bjørnstad, O.N., Shea, K., Krzywinski, M. & Altman, N. (2020) Points of significance: The SEIRS model for infectious disease dynamics. Nature Methods 17:557–558.

Background reading

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

Gene Machines

Fri 05-06-2020

Shifting soundscapes, textures and rhythmic loops produced by laboratory machines.

In commemoration of the 20th anniversary of Canada's Michael Smith Genome Sciences Centre, Segue was commissioned to create an original composition based on audio recordings from the GSC's laboratory equipment, robots and computers—to make “music” from the noise they produce.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Gene Machines by Segue. Now available on vinyl.


me as a keyword list

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