Canon Patent For 70-400 f/4.5-5.6 Lens

2014_21256_fig05

Egami (translated) spotted another patent filed by Canon. It appears that Canon is working on a 70-400mm f/4.5-5.6 lens.

  • Patent Publication No. 2014-21256,2014-21257
    • Publication date 2014.2.3
    • Filing date 2012.7.18
  • Example 2
    • Zoom ratio 5.45
    • Focal length f = 71.33-144.71-388.95mm
    • Fno. 4.63-4.84-5.83
    • Half angle ω = 16.87-8.50-3.18 °
    • Image height Y = 21.64
    • 240.00-284.68-303.83mm overall length of the lens
    • BF 75.92-79.30-95.93mm
    • 6-group zoom of positive and negative positive and negative positive and negative
    • (Part of the fourth group) anti-vibration
    • Rear Focus (Group 6)

Canon Powershot G1 X Successor and Other Gear To Be Announced February 12th?

Powershot G1 X

I have been told (thanks) that Canon will announce new gear on February 12th, one day before CP+ starts. One of the cameras that is going to be announced should be the successor of the Canon Powershot G1 X, the others should be DSLRs. The possible announcement of the G1 X replacement showed up also on other places.

No new specs of the PowerShot G1 X successor have been leaked so far, but we can expect something similar to the specs leaked some time go on the Chinese Xitek forum:

  • Same design as the G1X, with a slightly longer lens
  • DIGIC 6 Image Processor
  • 24 – 120mm f/2.8-5.8 lens
  • 20.2MP 1.5″ CMOS sensor
  • New optical zoom viewfinder with better image quality
  • 3.0″ LCD touch screen with 922,000 dots

Additionally [source: CR], it is now also rumored the G1 X successor could have WiFi and GPS. The camera should be available to the public at the end of April or beginning of May.

No word about the other gear that Canon might announce for CP+. Short time to wait, and then we will know.

Canon PowerShot G1 X price check: B&H Photo, Adorama, Amazon USA, Amazon Canada, Canon Canada, Canon USA

Inside Look at Canon’s EF Extenders (Canon DLC)

The Canon Digital Learning Center published part 2 of their article series about Canon EF and tele extenders (part 1 is here). Some extender basics from part 1:

  • Tele extenders cause an unavoidable loss in light transmission to the imaging sensor or film. There’s a constant, steady 1-stop light loss with 1.4x Extenders and a 2-stop loss with a 2x. This is consistent, regardless of camera or lens brand.
  • A 1.4x Extender multiplies the effective lens focal length by 1.4x. Thus, a 300mm lens would have the power and field of view of a 420mm lens. And a 2x Extender doubles the effective lens focal length.
  • When using a digital SLR with an image sensor smaller than a full-frame, it’s “crop factor” is added to whatever an extender is to calculate effective lens coverage relative to a full-frame camera. In other words: an EOS Rebel has a 1.6x crop factor. If using a 200mm lens with a 2x Extender (400mm equivalent), putting it on an EOS Rebel would result in a lens that effectively “acts” like a 640mm lens (400mm x 1.6 = 640mm) would on a full-frame or 35mm film camera.
  • Tele extenders do not impact or change a lens’ minimum focus distance. Because extenders do impact effective focal length, at minimum focus distance, a lens with extender provides a noticeably tighter composition of small objects than the lens alone would.
  • Canon EF 1.4x and 2x Extenders are exclusively designed to work with specific, compatible Canon EF lenses. Part of the reason for this is the front element design of Canon extenders, which literally projects forward and into the rear of any lens they’re attached to. This enhances optical performance with those lenses, but prevents their attachment to many lenses that have a rear element flush with the rear lens mount.
  • Canon EF lenses that are extender-compatible:
    • All fixed focal length EF L-series telephoto lenses, 135mm and above (thru 800mm)
    • All white-colored EF 70-200mm f/2.8 and f/4 L-series zoom lenses (all versions)
    • EF 100–400mm f/4.5–5.6L IS USM zoom
    • EF 200–400mm f/4L IS USM Extender 1.4x zoom (can be used in addition to lens’ built-in 1.4x)