Canon Patent To Automatically Find Best Irradiation Angle For Bounce Flashes

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Canon patent application US 2019-0230271 discusses methods and algorithm to automatically establish the optimal irradiation angle for bounce flashes.

In other words, the aim of the Canon patent application is automatically find the irradiation angle of each receiver-flash in a setup where you are using a plurality of receiver-flashes.

The Canon patent discusses…

[…] an image pickup apparatus that is capable of automatically finding an irradiation angle of each external flash in photographing using a plurality of external flashes. An image pickup apparatus controls external flashes that are communicably connected to one another and have light emitting units of which irradiation angles are variable. A photometry device obtains a photometry value. A memory device stores a set of instructions. At least one processor that executes the set of instructions to: obtain photometry values at times of emissions at each of different irradiation angles for each of the external flashes, generate an evaluation value at each of the different irradiation angles based on a photometry result obtained by the photometry device, and decide an irradiation angle for photographing of each of the external flashes based on the evaluation values generated.

The issue more detailed:

There is a known image pickup apparatus, such as a digital camera, that does not only irradiate an object directly with flash light but also enables what is called a bounce flash photographing by irradiating the entire area including the object with flash light that is directed to a ceiling by changing a flash-light irradiation angle and is reflected and diffused by the ceiling. Use of a receiver-flash during the bounce flash photographing enables various expressions. For example, a light amount balance between irradiation light from a right side of an object and irradiation light from a left side can be changed, and a shadow appearing in a background can be eliminated by irradiation light toward the background.

Appropriate determination of the irradiation direction of the flash light in photographing using a receiver-flash and the bounce flash photographing requires time and effort from a photographer. For example, an appropriate irradiation direction of flash light in the bounce flash photographing is decided by repeating test photographing at several times. In the photographing using a receiver-flash, if an irradiation direction of flash light of the installed receiver-flash has shifted from a direction toward a target, a photographer must go to the receiver-flash and adjust the irradiation direction.

In view of such failure, Japanese Laid-Open Patent Publication (Kokai) No. 2011-221364 (JP 2011-221364A) suggests a technique that repeats emission and photometry while changing an irradiation angle of flash light and stores the irradiation angle at which the maximum photometry value among the obtained photometry values except for photometry values within a predetermined range has been obtained. This suggestion enables to automatically find the angle at which an irradiation light amount to an object is maximized except for the irradiation angles directly directed to the object as the irradiation angle for the bounce flash photographing.

However, the technique disclosed in the above-mentioned publication cannot automatically find the irradiation angle of each receiver-flash in the photographing using a plurality of receiver-flashes.

SUMMARY OF THE INVENTION

[…] Accordingly, a first aspect of the present invention provides an image pickup apparatus controlling external flashes that are communicably connected to one another and have light emitting units of which irradiation angles are variable, the image pickup apparatus comprising a photometry device that obtains a photometry value, a memory device that stores a set of instructions, and at least one processor that executes the set of instructions to: obtain photometry values at times of emissions at each of different irradiation angles for each of the external flashes, generate an evaluation value at each of the different irradiation angles based on a photometry result obtained by the photometry device, and decide an irradiation angle for photographing of each of the external flashes based on the evaluation values generated.

Accordingly, a second aspect of the present invention provides a control method for an image pickup apparatus controlling external flashes that are communicably connected to one another and have light emitting units of which irradiation angles are variable, the control method comprising a photometry step of obtaining photometry values at times of emissions at each of different irradiation angles for each of the external flashes, a generation step of generating an evaluation value at each of the different irradiation angles based on a photometry result obtained in the photometry step, and a decision step of deciding an irradiation angle of each of the external flashes based on the evaluation values generated in the generation step.

According to the present invention, an irradiation angle of each external flash is controlled so as to irradiate an object or a background of the object in accordance with a setting in photographing using a plurality of external flashes.

More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these:

Canon Patent For 12-48mm f/1.8-4.0 Lens For EOS M System

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Canon patent application 2019-120821 (Japan) describes the optical formula for a 12-48mm f/1.8-4 lens for the Canon EOS M mirrorless camera system.

An excerpt from the Canon patent:

[…] provide a zoom lens which is small in the whole lens system, has a wide angle of view, a high zoom ratio, and a large aperture ratio and has high optical performance over an entire zoom range. 
[Means for solving]A 1 lens group having negative refractive power, a 2 lens group having positive refractive power, a 3 lens group having negative refractive power, and a 4 lens group having positive refractive power arranged in this order from the object side to the image side, and the 1 lens group is stationary at the time of zooming. In this zoom lens, a 2 lens group, a 3 lens group, and a 4 lens group are moved and an interval between adjacent lens groups is changed. The 4 lens group has 2 or more lenses, and appropriately sets a focal length f 2 of the 2 lens group, a focal length fw of the entire system at the wide-angle end, a moving amount M 2 of the 4 lens group during zooming from the wide-angle end to the telephoto end, and a moving amount M 4 of the second lens group during zooming from the wide-angle end to the telephoto end. 

More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these:

And Here Is One More Canon Patent Dealing With IBIS (In Body Image Stabilisation)

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Here is another Canon patent application (US 2019-0222763) dealing with IBIS (in Body Image Stabilisation).

As seen with another Canon patent about IBIS, here too the discussion is about how to make IBIS and lens IS work together smoothly. An algorithm is described that allows the camera to chose if use IBIS, lens IS, or both together.

Given all the recent Canon patent dealing with IBIS, you can safely assume that Canon will soon feature it on their camera bodies. Most likely first on the EOS R system, but there has also been a patent discussing IBIS on a DSLR.

So, IBIS is coming to the Canon universe. Sure thing.

More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these:

Canon Patent: Apodization Filter For EF Lenses

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Canon patent application 2019-0219789 describes formulas and technology about how to apply an apodization filter to EF mount lenses.

The following lenses are discussed in the patent application:

  • Canon EF 50mm 1.4
  • Canon EF 24mm 1.4
  • Canon EF 35mm 1.4
  • Canon EF 135mm 2.0

More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these:

Canon Patent Describes How To Feature IBIS (In Body Image Stabilisation) On A DSLR

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Canon patent application US20190215454 describes how to implement IBIS (In Body Image Stabilisation) in a DSLR. We saw other Canon patent applications dealing with IBIS but this is the first time it is related to a DSLR

More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these:

Canon Patent For A Lens Cap That Might Be Pretty Difficult To Lose

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Canon patent application 2019-113645 describes a design for a lens cap that might once for all solve the issue with lost lens caps.

The lens cap described in the Canon patent opens (and closes) without being removed form the lens. There is more: the lens cap is a lens cap when closed and becomes a lens hood when opened. Pretty smart.

The present invention works as a lens hood function at the time of shooting and as a lens protection function at the time of non-shooting, thus eliminating the need for lens cap attachment / removal and barrier opening / closing operations.

More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these: