December 18, 2014, 06:54:09 PM

Author Topic: EF 300 f/4L IS II Patent  (Read 10016 times)

/dev/null

  • Guest
Re: EF 300 f/4L IS II Patent
« Reply #15 on: February 15, 2011, 04:56:46 PM »
A pizoelectric crystal is extremely reliable, and if the moving lens group in the IS were eliminated, the reliability might be greatly increased.   One of the big hits lenses took in reliability was with the introduction of the moving IS elements.  This is not to say that they are horribly unreliable, but they are a weak link.

Fully agree. Each moving element less can only mean better shock resistance and less wear and tear.

Quote
I really do not expect to see a lens that uses the principle soon, but it would be interesting to see what actually happens to reliability.  We do not have enough information about the actual construction to do a accurate analysis, and early implementations will likely be improved on later.

We are still waiting for significant improvements of the DO principle. There are some patents out there, but no products...

canon rumors FORUM

Re: EF 300 f/4L IS II Patent
« Reply #15 on: February 15, 2011, 04:56:46 PM »

CR Backup Admin

  • Administrator
  • 1D Mark IV
  • *****
  • Posts: 809
    • View Profile
Re: EF 300 f/4L IS II Patent
« Reply #16 on: February 16, 2011, 12:41:44 AM »
Canon still includes examples with pellicle mirrors in some of their patents, and they haven't released one for many years.  Many patents are filed to protect a technology and prevent someone doing something clever with it.

Companies are often blind to inventors ideas, the company I worked for turned down a patent by a employee that covered a method to deal with the Y2K situation.  They signed over the rights to him, and he had it patented.  When it became a very popular solution, he popped up with his patent and cleaned up.

GMCPhotographics

  • 5D Mark III
  • ******
  • Posts: 728
    • View Profile
    • GMCPhotographics
Re: EF 300 f/4L IS II Patent
« Reply #17 on: February 16, 2011, 06:34:42 AM »
Personally, I hope the 400mm f/5.6L gets updated first...

I really hope they change that one to a 500 f/5.6 L IS ... that would be a hotter item than a themos full of lava

And heavier too!




yes, but not prohibitively so.  adding IS to the 400 f/5.6 is bound to up its weight already anyway.  meanwhile there are Sigma zooms that go to 500mm featuring OS that weigh in under 2 kilos; I don't think there's any reason a canon 500 f/5.6 L IS prime lens should be any heavier.  1900g for a tack-sharp 500mm lens would be very exciting for a lot of people.  the new 500mm f/4 L IS II, despite its major weight reduction, still comes in at over 3 kilos.  it's a world of difference

The front element alone would make this a hugh ticket, high weight item. The current 400mm f5.6 can get away with a 77mm front filter. A 500mm f5.6 would need a front element of around 90mm....which is quite close to the size of front element in a 300mm f2.8. So it'll be in that kind of price / weigth bracket.

canon rumors FORUM

Re: EF 300 f/4L IS II Patent
« Reply #17 on: February 16, 2011, 06:34:42 AM »