Canon Still in Deep Research of Canon EF Cinema Lenses

[Richard CR]

This is a curious patent application from Canon. From the designs, it’s pretty evident that these aren’t your usual mirrorless zoom lenses.

A little background first on what we use to determine use cases for lenses. It’s all about the image height.

Canon Still in Deep Research of Canon EF Cinema Lenses - Canon Rumors

This is a curious patent application from Canon. From the designs, it’s pretty evident that these aren’t your usual mirrorless zoom lenses. A little background first on what we use to determine use cases for lenses. It’s all about the image height. The image height on Canon’s published...

www.canonrumors.com

 

[jannatul18]

Interesting find. Canon seems to be keeping cinema glass development pretty active, even with all the push toward RF lenses. Makes me wonder if they’re planning something bigger for the cine line, or just protecting patents for future options.

 

[Bob Howland]

These lenses raise a question. Why can't/don't still zoom lenses hold the larger aperture for as much of the zoom range as possible. For example, a 300 f/2.8 lens requires a front element of about 107mm. Now consider a 100-300 f/2-2.8. That 107mm should allow that f/2 to be maintained out to 214mm. So why doesn't it? My fantasy lens would be a 200-500 f/2.8-4 with a selectable 1.4x TC. Update: It would hold f/2.8 out to 350 mm.

 

[Eloniel]

These lenses raise a question. Why can't/don't still zoom lenses hold the larger aperture for as much of the zoom range as possible. For example, a 300 f/2.8 lens requires a front element of about 107mm. Now consider a 100-300 f/2-2.8. That 107mm should allow that f/2 to be maintained out to 214mm. So why doesn't it? My fantasy lens would be a 200-500 f/2.8-4 with a selectable 1.4x TC. Update: It would hold f/2.8 out to 350 mm.

That's a great point, I can see 3 answers:

• Image quality not up to L standards on the wider end with larger aperture.
• Perceived quality, constant aperture is often seen as holy grail for zoom lenses and variables one something for entry level lenses.
• Selling more lenses, if you provide a 200-500 f2.8-4.0 with 2.8 up to 350mm, who would buy a 400mm f2.8 ? We're speaking of a 13K€ lense that would not sell. I could see sigma doing it but not Canon.

 

[Quack]

These lenses raise a question. Why can't/don't still zoom lenses hold the larger aperture for as much of the zoom range as possible. For example, a 300 f/2.8 lens requires a front element of about 107mm. Now consider a 100-300 f/2-2.8. That 107mm should allow that f/2 to be maintained out to 214mm. So why doesn't it? My fantasy lens would be a 200-500 f/2.8-4 with a selectable 1.4x TC. Update: It would hold f/2.8 out to 350 mm.

Take a look at a zoom lens and you will see a chassis to carry the aperture blades down the barrel, and as the chassis moves down the barrel, you no longer have a 107mm opening. The opening is now down the barrel, not the opening at the end of the lens. That's how it seems to me, anyway and why these types of variable apertures would require a much larger front element and be much larger and heavier than people think. Maybe not even possible to design.