Canon Patent: 400mm f/4 DO IS Extender 1.4x and 600mm f/4 IS Extender 1.4x

Canon Patent

A new Canon patent application was spotted. 400mm f/4 DO IS Extender 1.4x and 600mm f/4 IS Extender 1.4x are discussed.

Canon patent application 2022-22771 discusses optical formulas for two rather interesting lenses:

  • 400mm f/4 DO IS Extender 1.4x
  • 600mm f/4 IS Extender 1.4x

PROBLEM TO BE SOLVED: To provide an optical system in which a magnification conversion optical group can be inserted and removed and the total length is short.

As a method of changing the focal length of the optical system used for imaging, there is a method of inserting a magnification conversion optical group such as an extender into the optical path . Further, as an optical system in which the total length (distance from the optical surface on the object side to the image surface) does not change due to the insertion / removal of the magnification conversion optical group, Patent Document 1 describes the axial light beam between the aperture stop and the image surface. An optical system capable of inserting and removing a magnification conversion group at a converging position is disclosed.

However, if a space for inserting the magnification conversion optical group is provided between the aperture diaphragm and the image plane as in Patent Document 1, the total length of the original optical system becomes long . Further, if the magnification conversion optical group is inserted in a narrow space, various aberrations of the optical system may increase. The
present invention provides an optical system in which a magnification conversion optical group can be inserted and removed, but the total length is short and good optical performance can be obtained.

Example 1

  • Focal length: 392.58
  • F value: 4.12
  • Half angle of view: 3.15
  • Image height: 21.64
  • Overall length: 280.33
  • Back focus: 36.01

Example 1 (with inserted teleconverter)

  • Focal length: 549.72
  • F value: 5.77
  • Half angle of view: 2.25
  • Image height: 21.64
  • Overall length: 280.33
  • Back focus: 36.00

Example 5

  • Focal length: 585.00
  • F value: 4.12
  • Half angle of view: 2.12
  • Image height: 21.64
  • Overall length: 467.45
  • Back focus: 55.50

Example 5 (with inserted teleconverter)

  • Focal length: 819.18
  • F value: 5.77
  • Half angle of view: 1.51
  • Image height: 21.64
  • Overall length: 467.45
  • Back focus: 55.50

The Canon patent application was spotted by asobinet.com. More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these:

Canon Expands Dragonfly Telephoto Array With 120 EF 400mm f/2.8L IS II Lenses

Dragonfly Telephoto Array

We reported about the Dragonfly Telephoto Array in the past. It’s a project developed by the University of Toronto’s Dunlap Institute for Astronomy and Astrophysics for which Canon delivers the optics.

The Dragonfly Telephoto Array started with 10 lenses and is designed to reveal

[…] the faint structure [of the universe] by greatly reducing scattered light and internal reflections within its optics. It achieves this using ten, commercially available Canon 400mm lenses with unprecedented nano-fabricated coatings with sub-wavelength structure on optical glasses.

Now Canon provides 120 (one-hundert-twenty) more EF 400mm f/2.8L IS II lenses to the array. So, now that you got what it is about, here is a more detailed description about the Dragonfly Telephoto Array:

The Dragonfly Telephoto Array is a novel telescope concept designed to image large and extremely faint structures in the night sky. These structures hold important clues to the distribution and nature of dark matter, the elusive substance whose contribution to the total mass-energy density of the Universe is five times higher than that of normal matter. These structure are hard to see with conventional telescopes due to a combination of scattered light from bright stars and their mosaicked detectors. Dragonfly harnesses the power of commercially-available high-end telephoto lenses to address these issues. The latest generation of Canon 400 mm f/2,8 lenses have superb anti-reflection properties, owing to one of the first applications of nano-fabricated coatings with sub-wavelength structures on optical glasses. Furthermore, each lens is equipped with a single monolithic wide-field detector covering six square degrees, and with multiple redundant lines of sight Dragonfly achieves extremely accurate modeling of the night sky emission. 

Commissioned in 2013 with three lenses, the array currently consists of 48 lenses in two clusters of 24. Optically the telescope functions as the equivalent of a 1.0 m diameter refractor with a focal ratio of f/0.4, the largest and by far the most sensitive lens telescope in existence. “Behind the scenes” innovations include the use of AI planning tools to optimize nightly operations and survey design, unit-based basic data processing with compute sticks, the application of Internet of Things operational protocols to communicate with the 48 lenses, and fully automated gate-driven cloud-based data analysis. Our dual goals are to:

1. Improve our understanding of dark matter through study of the low surface brightness universe

2. Harness the potential of distributed telescopes, combined with advances in information technology, for transformational science

Canon press release:

Canon U.S.A. Inc., to Provide 120 EF 400mm f/2.8L IS II USM Lenses for Expansion of the Dragonfly Telephoto Array Project

MELVILLE, NY, November 18, 2021 Canon U.S.A. Inc., a leader in digital imaging solutions, today announced the company will provide technical assistance to Project Dragonfly, an international research team from Yale University, and the University of Toronto, in its plan to expand the Dragonfly Telephoto Array. The company will provide the project with 120 Canon EF 400mm f/2.8L IS II USM large-aperture super-telephoto single-focal length lenses, and its parent company, Canon Inc., will provide technical assistance.

The Dragonfly Telephoto Array is a telescope array equipped with multiple Canon large-aperture super-telephoto single focal length lenses – specifically, the Canon EF 400mm f/2.8L IS II USM lens. The telescope was designed in 2013 by Project Dragonfly, an international research team from Yale University and the University of Toronto. The Dragonfly Telephoto Array is capable of capturing images of galaxies that are so faint and large that they had escaped detection by even the largest conventional telescopes. Its mission is to study the low surface brightness universe to elucidate the nature of dark matter and to utilize the concept of distributed telescopes.

In support of this research, Canon provided technical assistance by supplying 40 Canon EF 400mm f/2.8L IS II USM lenses in 2015, expanding the array to 48 lenses with 24 telescopes bundled on two separate mounts. Since then, the research team has produced significant results in extragalactic astronomy, including discovering the ultra-diffuse galaxy Dragonfly 44 in 2016 and the identification of a galaxy that lacks dark matter, NGC 1052-DF2, in 2018.

This time, Canon will provide technical assistance by supplying 120 Canon EF 400mm f/2.8L IS II USM lenses to the research team, further expanding the telescope array. With a total of 168 lenses, the telescope array has a light-gathering capability equivalent to that of a refracting telescope of 1.8 meters in diameter, with a focal length of only 40 cm, and is expected to open new windows on the universe.

Canon is committed to contributing to the development of science and technology by leveraging the technological strengths it has cultivated as a leading imaging company.

Message from Professor Pieter van Dokkum of Yale University comments

The Dragonfly Telephoto Array is the pre-eminent survey telescope for finding faint, diffuse objects in the night sky. It has enabled us to discover ultra-diffuse galaxies and other low-surface brightness phenomena—rendering images that deepen our understanding of how galaxies are formed and providing key insights into the nature of dark matter. The initial array was equipped with 48 Canon EF 400mm telephoto lenses featuring anti-reflection coatings that mitigate the effects of light scattering, overcoming the limitations of conventional telescopes in detecting faint structures. The lenses are coupled to monolithic wide-field detectors that permit excellent error control. With the addition of 120 of these lenses, in a newly developed configuration allowing extremely narrow filters to be used, Dragonfly will be the most powerful wide-field spectroscopic line mapping machine in existence. A major goal of the next iteration of the Dragonfly array is to detect and study the faint gas thought to exist around and between galaxies. By opening this new window on the cosmos, Dragonfly will tackle some of the most critical questions in astrophysics today.

Canon RF 400mm f/2.8L IS Review (physically awesome, optically impeccable)

Canon RF 400mm F/2.8L'

So, we are talking about a $12,000 lens here. Welcome to a new Canon RF 400mm f/2.8L IS review. How doesn’t have a spare kidney?

At a glance:

  • RF-Mount Lens/Full-Frame Format
  • Aperture Range: f/2.8 to f/32
  • Optical Image Stabilizer
  • Super UD and Fluorite Elements
  • Super Spectra and Air Sphere Coatings
  • Customizable Electronic Focusing Ring
  • Two Focus Presets
  • Circular 9-Blade Diaphragm
  • Weather-Sealed Design, Fluorine Coating
  • Rotatable Tripod Collar

Christopher Frost posted his Canon RF 400mm f/2.8L IS review. He says:

This is literally the highest quality camera lens I have ever handled – physically awesome, optically impeccable…and incredibly expensive. Canon have been honing the craft of designing and producing these lenses for years, now: what can this latest version achieve to make it worth its asking price?

Watch the video below to learn what makes this lens so awesome, and so expensive.

Another rather interesting Canon RF 400mm f/2.8L IS review can be seen here.

Canon RF 400mm f/2.8L IS:

America: B&H Photo, Adorama, Amazon USA, Amazon Canada, Canon Canada, Canon USA
Europe & UK: Amazon DE, Amazon UK, Amazon IT, Wex Photo Video, Canon DE, Canon UK

Click here to open the rest of the article

Canon RF 400mm f/2.8L IS USM & RF 600mm f/4L IS Lenses Review

RF 400mm F/2.8L

The Canon RF 400mm f/2.8L IS and the Canon RF 600mm f/4L IS are two professional and expensive optical masterpieces by Canon, Together the two super-telephoto lenses are worth $25,000.

The Canon RF 400mm f/2.8L IS and the Canon RF 600mm f/4L IS have been announced in April 2021, along with the first development announcement of the EOS R3. Indeed, both lenses seem to have been made for the R3. Gordon Laing had the rare chance to have the Canon RF 400mm f/2.8L IS and the RF 600mm f/4L IS in his hands and he shares his review and impression in the video below.

Impressive lenses. Thanks Gordon. Canon made some other awesome lenses for the EOS R3.

Canon RF 400mm f/2.8L IS at a glance:

  • RF-Mount Lens/Full-Frame Format
  • Aperture Range: f/2.8 to f/32
  • Optical Image Stabilizer
  • Super UD and Fluorite Elements
  • Super Spectra and Air Sphere Coatings
  • Customizable Electronic Focusing Ring
  • Two Focus Presets
  • Circular 9-Blade Diaphragm
  • Weather-Sealed Design, Fluorine Coating
  • Rotatable Tripod Collar

Canon RF 400mm f/2.8L IS:

America: B&H Photo, Adorama, Amazon USA, Amazon Canada, Canon Canada, Canon USA
Europe & UK: Amazon DE, Amazon UK, Amazon IT, Wex Photo Video, Canon DE, Canon UK

Canon RF 600mm f/4L IS at a glance:

  • RF-Mount Lens/Full-Frame Format
  • Aperture Range: f/4 to f/32
  • Super UD and Fluorite Elements
  • Super Spectra and Air Sphere Coatings
  • Customizable Electronic Focusing Ring
  • Optical Image Stabilizer
  • Two Focus Presets
  • Circular 9-Blade Diaphragm
  • Weather-Sealed Design, Fluorine Coating
  • Rotatable Tripod Collar

Canon RF 600mm f/4L IS:

America: B&H Photo, Adorama, Amazon USA, Amazon Canada, Canon Canada, Canon USA
Europe & UK: Amazon DE, Amazon UK, Amazon IT, Wex Photo Video, Canon DE, Canon UK

More about the lenses after the break.

Click here to open the rest of the article

Canon Might Announce More RF Mount Super-telephoto Lenses In 2021

RF 600mm F/4L Super-telephoto

The Canon RF 400mm and RF 600mm, both announced last week, might not be the only super-telephoto lenses for the RF mount to get released in 2021.

According to a new rumor, at least two more super-telephoto lenses are in development. A Canon RF 400mm f/4 DO IS USM lens might get announced and it could be the smallest and lightest of its kind, with a redesigned optical formula for the RF mount system. A Canon RF 200-500mm f/4L IS USM might also get announced. No more information on this one but it might not have a built-in teleconverter (as the EF 200-400mm f/4L IS USM 1.4x does).

Stay tuned, and stay safe.

Source: Canon Rumors

Canon Announced The RF 400mm f/2.8L IS and Canon RF 600mm f/4L IS Lenses

RF 600mm F/4L Super-telephoto

Along with the Canon EOS R3 and the RF 100mm f/2.8 Macro, Canon also announced two telephoto lenses for the RF mount, the Canon RF 400mm f/2.8L IS USM and Canon RF 600mm f/4L IS USM.

Both lenses are anything but inexpensive, the RF 400mm goes for $11,999 and the RF 600mm for $12,999. Both lenses are scheduled to ship in July 2021. Preorders are open.

Canon RF 400mm f/2.8L IS USM:

America: B&H Photo, Adorama, Amazon USA, Amazon Canada, Canon Canada, Canon USA
Europe & UK: Amazon DE, Amazon UK, Amazon IT, Wex Photo Video, Canon DE, Canon UK

Canon RF 600mm f/4L IS USM:

America: B&H Photo, Adorama, Amazon USA, Amazon Canada, Canon Canada, Canon USA
Europe & UK: Amazon DE, Amazon UK, Amazon IT, Wex Photo Video, Canon DE, Canon UK

Here are some hands-on and first impression reviews:

David Bergman for Adorama reviews the new RF 400mm and RF 600mm (below).

Gordon Laing looks at the new Canon RF lenses (below).

And here are more hands-on reviews:

Canon press release:

The Canon RF400mm F2.8L IS USM and Canon RF600mm F4L IS USM are both designed to be optically identical to their EF counterparts. The RF400mm and RF600mm weigh in at 6.37 and 6.81 pounds with a minimum focusing distance of 8.2 and 13.8 feet, respectively. Both lenses share many of the same critical features that help professional high-end super-telephoto lenses stand out from the crowd. Those features include:

  • Ideal for a wide variety of shooting situations, including sports, aviation, trains, automotive, and wildlife, such as birding.
  • Optical Image Stabilization with up to 5.5 stops6 of shake correction. Including three IS Operation Modes — still subjects, panning, and irregular movement.
  • Proprietary Canon lens coatings, Super Spectra Coating (SSC), and Air Sphere Coating (ASC) help minimize ghosting and flaring. Lens placement and coatings are optimized to provide users with clear, high-contrast images even when there is a bright light source.
  • Lenses include fluorite and super UD lens elements arranged in such a way to help correct chromatic aberration and make the models more compact. Like the latest Canon EF400mm f/2.8L IS III USM and EF600mm f/4L IS III USM lenses, released in the fall of 2018, weight on these RF-series super-telephotos has been significantly reduced vs. previous-generation Canon super tele designs.
  • Compatible with Canon RF 1.4x and 2x extenders, and feature a customizable electronic focus ring, with manual focus capability during SERVO AF.
  • A nine-blade circular aperture provides users beautiful bokeh and ideally blurred backgrounds when the aperture is stopped down.
  • For added convenience when on a shoot, two focus presets are available. Users can instantly return to one of two memorized focus distances.
  • Rugged Canon L-series dust and water-resistant design with vibration and shock resistance. The front element has been dressed with a fluorine coating for easy cleaning.
  • Infrared reflective pigments with high reflectance and titanium oxide lens barrel coating with silica provide excellent UV weather resistance and heat reduction.

Canon RF Lenses Pricing and Availability
The Canon RF100mm F2.8 L Macro IS USM, Canon RF400mm F2.8 L IS USM and Canon RF600mm F4L IS USM are scheduled to be available in July 2021 for an estimated retail price of $1,399.00, $11,999.00 and $12,999.00, respectively*. For more information, please visit usa.canon.com.