The Canon EF-M 28mm f/3.5 Macro IS STM lens

There are not a lot of native lenses found in the Canon EF-M series, but this is changing with a number of new offerings. There is a new 18-150mm general purpose zoom that looks pretty good.  The new lenses include a rather specialized lens, the EF-M 28mm f/3.5 Macro IS STM, a purpose built macro lens.

EOS M5 and 28mm f/3.5 macro lens
EOS M5 and 28mm f/3.5 macro lens

This lens is different. The lens is designed from the start to be a macro lens, not a general purpose lens that also does a little macro as a secondary feature.  There are a number of features that are quite unusual found on this macro lens.

The first, and most obvious feature is the built-in ring light, a rather useful feature in very close macro photography where light is everything. A set of bright white LEDs is arranged on the front of the lens behind a diffuser. The LED’s are powered by the camera, no separate battery is necessary.

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Astronomers Measure Universe Expansion, Get Hints of ‘New Physics’

W. M. Keck Observatory press release

Astronomers have just made a new measurement of the Hubble constant, the rate at which the universe is expanding, and it doesn’t quite line up with a different estimate of the same number. That discrepancy could hint at “new physics” beyond the standard model of cosmology, according to the team, which includes physicists from the University of California, Davis, that made the observation.

Lensed Quasar HE0435-1223
The image of this quasar is split into four by a massive galaxy acting as a gravitational lens. Image credit: Sherry Suyu, European Space Agency/Hubble Space Telescope/NASA
The Hubble constant allows astronomers to measure the scale and age of the universe and measure the distance to the most remote objects we can see, said Chris Fassnacht, a physics professor at UC Davis and a member of the international H0LiCOW (H0 Lenses in COSMOGRAIL’s Wellspring) collaboration, which carried out the work.

Led by Sherry Suyu at the Max Planck Institute for Astrophysics in Germany, the H0LICOW team used the NASA/ESA Hubble Space Telescope and other space- and Earth-based telescopes, including the Keck telescopes in Hawaii, to observe three galaxies and arrive at an independent measurement of the Hubble constant. Eduard Rusu, a postdoctoral researcher at UC Davis, is first author on one of five papers describing the work, due to be published in the Monthly Notices of the Royal Astronomical Society.

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Macrophotography With Extension Tubes

One of the advantages of a mirrorless camera, like the EOS-M, is the very shallow backfocus requirement. The distance from the lens mount to the sensor is quite small, allowing use of just about any series of lenses on the market. All that is needed is the correct adapter, a need that several specialty manufacturers have addressed with products. The result is that the camera is useful in a wide range of photographic experiments and projects.

Gecko & Plumeria
A gold dust day gecko (Phelsuma laticauda) on a plumeria blossom
This includes older lenses from years past such as the Canon manual focus FD lenses or the Leica M lenses from decades ago. I have a number of these excellent lenses, mostly Nikon and Canon, the fast primes once treasured by photographers for their optical quality. Because these old lenses are not suited for use with modern DSLR’s they are often relegated to eBay and discount shelves in used camera stores. This does not mean they are obsolete, there are creative uses still available for these classic lenses.

I have had fun simply shooting with these old primes and the EOS-M camera. Sometimes I will grab a single lens and just go someplace to play with the camera for half an hour, sort of a self imposed creative exercise. Using one of these manual focus lenses brings back memories of my first years of film photography, before the days of auto-focus.

Combine these old lenses with an extension tube, and the rig becomes a macro-photography setup capable of fairly high magnification.

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Cassini’s Optics

I have always enjoyed learning about the history of astronomy, it is a science whose roots can be traced continuously back to the dawn of human history.

One of my Facebook friends is a bit of an old telescope nut, even more so than myself, regularly posting photos of historic observatories and in particular old refactors. I too have a soft spot for these historic instruments, going out of may way to visit Greenwich Observatory in London, to drive up Mt. Hamilton to see the beautiful old refractor at Lick Observatory, or flying across the country to see one of William Herchel’s telescopes on display at the Smithsonian.

Ovidiu Cotcas recently posted a link to a fun research paper analyzing the telescope optics of Cassinni’s telescopes. These instruments were state of the art in the mid-1600’s, a period when the first telescopes were being used to provide the first good look at astronomical objects, revolutionizing our understanding of the universe. Only five decades after Galileo astronomers across Europe were attempting to build ever better instruments to provide views of the planets that had only recently been nothing but moving lights in the heavens. These early telescopes showed that planets were worlds, opening a whole new realm to observation and study.

Paris Observatory XVIII Century
Paris Observatory in the times of Cassini during the late 1600’s showing the very long focal length refracting telescopes of the day. Credit: Wikimedia Commons
Prior to the invention of the achromatic doublet in 1758 the main limitation of refracting telescopes was chromatic error. A single lens is also a prism, focusing the different colors of light at different focal lengths. The only solution to this was to make objective lenses with very long focal lengths. Today’s telescopes use compound lenses of two or three elements in the objective with different types of glass. This combination of lenses can be cleverly arranged to cancel out chromatic error resulting in an achromatic lens.

The long focal lengths of those first singlet lens telescopes appear absurd by modern standards, huge instruments with long tubes suspended from masts or with the objective lenses mounted upon tall towers while the observer and eyepiece were at ground level. Telescopes were thirty or even a hundred feet long. Unlike today’s convention of referring to a telescope’s aperture, telescopes were referred to by focal length. Cassini’s primary instruments had focal lengths of between 17 and 40 feet, with one having the incredible focal length of 150ft! As familiar as I am with using small telescopes I shudder at the challenges of aligning and aiming such an instrument, much less tracking a target across the sky.

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Vintage Glass

One of the advantages of a mirrorless camera, like the EOS-M, is the very shallow backfocus requirement. The distance from the lens mount to the sensor is quite small, allowing use of just about any series of lenses on the market. All that is needed is the correct adapter, a need that several specialty manufacturers have addressed with products. The result is that the camera is useful in a wide range of photographic experiments and projects.

EOS-M with Canon 24mm f/2.8 FD
The EOS-M with a Canon 24mm f/2.8 FD lens mounted
This includes older lenses from years past such as the Canon manual focus FD system from decades ago. Forgotten by most, these lenses have none of the modern features photographers have come to expect. No autofocus, no image stabilization, just solid optics from an age now past. These old lenses are not obsolete, there are creative uses still available for these classic lenses.

Any sort of zoom lens need not apply, the quality of the older zoom lenses often suffered. Designed without the aid of modern optical design software and without aspheric elements these designs fall short of modern standards.

You can find these classic lenses languishing on shelves in the back of camera stores, in garage sales and on eBay. There is a lot of junk out there, it takes some research to differentiate the good from the bad. A couple quick rules of thumb will sort out most of the junk… Stick to a first rank name in old camera gear; Canon, Nikon, Ziess, Hasselblad, and Leica. The next hint of a hidden gem is the focal ratio. The classic primes were fast, f/2.8 or faster. Still, it is wise to look up the history of the lens before plunking down any cash. The good lenses will be well written about, even in modern times. You will find good references with a quick web search.

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Supernova Split into Four Images by Cosmic Lens

W. M. Keck Observatory press release

Astronomers have for the first time spotted four images of a distant exploding star, arranged in a cross-shape pattern by a powerful gravitational lens. In addition to being a unique sighting, the discovery will provide insight into the distribution of dark matter. The findings will appear March 6 in a special issue of the journal Science, celebrating the centenary of Albert Einstein’s Theory of General Relativity.

This image shows the light of a supernova split into four images by a foreground elliptical galaxy embedded in a giant cluster of galaxies. The four images were spotted on Nov. 11, 2014. Credit: NASA/ESA
Two teams spent a week analyzing the object’s light, confirming it was the signature of a supernova, then turned to the W. M. Keck Observatory on Mauna Kea, in Hawaii, to gather critical measurements including determining the distance to the supernova’s host galaxy 9.3 billion light-years from Earth.

To explain the unique, four-up projection, the scientists determined a galaxy cluster and one of its massive elliptical members are gravitationally bending and magnifying the light from the supernova behind it, through an effect called gravitational lensing. First predicted by Albert Einstein, this effect is similar to a glass lens bending light to magnify and distort the image of an object behind it. The multiple images, arranged around the massive elliptical galaxy, form an Einstein Cross, a name originally given to a multiple-lensed quasar that appear as a cross.

Although astronomers have discovered dozens of multiply imaged galaxies and quasars, they have never seen a stellar explosion resolved into several images. “It really threw me for a loop when I spotted the four images surrounding the galaxy – it was a complete surprise,” said Patrick Kelly of the University of California, Berkeley, lead author of the paper and a member of the Grism Lens Amplified Survey from Space (GLASS) collaboration. The GLASS group is working with the FrontierSN team to analyze the supernova.

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Using the Nifty Fifty

Some photo instructors advocate using only a fifty millimeter fixed focal length lens as a creative exercise. A nice idea for an exercise, but I really did not want to do this while on an extended trip along the Alaskan and British Columbia coast by boat.

A workshop at Lagoon Cove, British Columbia
I did not get a choice in the matter.

Looking to pack light I had taken only three lenses to accompany the Canon 60D that would travel with me. This set included a Canon EF-S 17-85mm f/4-5.6 IS USM Lens, a 70-200mm f/4 L series telephoto, and a 50mm f/1.8. The 50mm was almost left behind, I grabbed it on a whim while packing realizing that it took up very little room.

It was a few days into the trip when trouble appeared. I began to get occasional errors when using the 17-85mm, the camera complaining about a lens communication error. After a day this became a serious issue, the camera refusing to take photos with the lens. The other lenses worked fine, thus I was sure the trouble was in the lens, not the camera.

A set of tools awaiting use in the workshop at Lagoon Cove
Sitting down and experimenting, I discovered that the issue only occurred if I was attempting to stop down the lens, used wide open I had no problem. During a series of gray and dark days, this proved little issue, I just set for aperture priority and continued to shoot, with some loss of creative control.

A couple more days and even that solution failed, the lens just jammed up entirely, with the aperture stop about halfway closed.

I was down to the the telephoto and the 50mm… Time to get creative.

The 50mm lens is interesting. It is small. It feels like you have forgotten to put a lens on the camera. It is sharp! The lens may be the cheapest lens Canon sells, just over $100, but there is nothing to complain about in the performance, crisp and sharp photos from corner to corner. It is fast. The very fast f/1.8 ratio allows for photos in low light conditions as well as providing a wonderfully shallow depth of field when you want it.

Cans of nails in the workshop at Lagoon Cove
I really missed the flexibility of a zoom and the 17mm wide angle in the close confines of the boat. The ability to go from wide to a moderate 85mm telephoto in a flash was a major issue when something popped up unexpectedly, something that happens on a boat in the wilds of Alaska.

I did have my little Canon G11 along, giving me some capability with a zoom lens. But I really wanted to shoot with the DSLR and the higher photo quality offered by the big lens and larger sensor when the photo really mattered.

On an APS-C camera like the Canon 60D there is a 60% crop factor, converting a 50mm to a mild telephoto. With a fixed focus I had to control the field through positioning myself instead of adjusting the camera. I do wonder if I got better shots as I had to become more involved and plan the shot?

I did take some great shots with the 50mm. Going through the 1,800+ photographs from the cruise I am quite happy with a number of them. An unintentional creative exercise, but a successful one.

Keck in Motion Scene Guide

I have been getting a few questions about the video. To answer a few of them I have compiled a guide to the scenes. Some quick explanations to what you are seeing, information on the camera used as well as the exposure information.

The video is a combination of two techniques. Many scenes were filmed as standard video then accelerated during editing to allow the motion to become clear. Examples of this are scenes of telescopes slewing and the interferometer delay lines moving.

Slower subjects, such as clouds or the stars moving across the sky, were photographed as time lapse. Here a large number of still images were taken. These are then processed and converted to video using Photoshop CS5 before loading into the video editing software, Adobe Premiere Elements. To construct the time lapse sequences sometimes required thousands of separate images, quickly filling memory cards and exhausting batteries. After dark it is long exposure time lapse that is used, with individual exposures often 15 seconds to one minute long.

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