Caught this thread today and it reminded me of when I was debating switching systems a while back. I have learned to be pretty cautious with these high-end rumors tho. A few years back, I actually passed on the Canon RF 100-500mm f/4.5-7.1 L IS USM because I was convinced a faster f/4 version was coming any day. I ended up waiting over a year with no lens at all and missed a whole season of birding... it was a huge mistake. Nowadays I look at my Sony FE 100-400mm f/4.5-5.6 GM OSS and realize having a lens today is way better than a dream lens next year. If youre looking at a potential 150-400 GM, just keep in mind how heavy that glass will actually be.

• Be careful with the weight; f/4 at 400mm is gonna be way heavier than any G Master zoom youve probably used before.
• Make sure to check your current tripod head weight rating before committing to a lens that big.

実施例1

• 焦点距離：154.53-387.86
• F値：4.12
• 画角：15.94-6.39
• 像高：21.64
• 全長：339.98

?resize=300%2C254&ssl=1 300w" data-sizes="auto" data-eio-rwidth="755" data-eio-rheight="640" />

Jumping in here because I am absolutely obsessed with those patent numbers!! The math on the optical formula is just amazing. If they actually pull off a constant f/4 at 400mm, the light gathering will be fantastic for those low light dawn shots! I totally agree that the patent data basically confirms they are testing prototypes. Few things I am already planning for it:

• Tinkering with a custom Arca-Swiss plate since standard ones might not balance a lens this long
• Building a DIY rain cover that actually fits the larger barrel diameter I really think Sony is gonna blow everyone away with the weight savings compared to the old DSLR versions... love it! Hit me up if you want to look at the optical schematics when they finally drop!

Wow, this lens will be great lens for sports and wildlife, but I can’t afford this lens I guess.

There is a patent for this lens already, you can search the web

Maybe in 2025 ?