cjc2 Loc: Hellertown PA

I'm waiting for a 14-1200 F2.8 or F4! Best of luck.

MrPhotog

Eric, there are currently teleconverters on the market that magnify the image. These sit between the main lens and the camera body. 2x and 3x converters have been around over 60 years. 1.4x converters are more recent.

A 1.4 converter on that 200 - 600 mm lens would create a lens that would be 1f/stop slower, but have a focal length of 280 - 840 mm. This would exceed your desired 300-800 mm range.

With a 2x converter on that lens it would become 2 stops slower but have a range of 400 - 1200 mm.

So, yes, it is optically possible to make lenses in the zoom ranges you want, and for a few dollars you can do it yourself.

Would photographers want to purchase these? Sure. Remember Barnum: “There’s a sucker born every minute”. They already sell lots of these 1.4x and 2x converters, and someone is bound to try one on any lens they can get their hands on!

There are a few caveats. First is the loss of light. If you want an 800 mm f/4 lens (prime or zoom) the front element needs to be at least 200 mm in diameter. (nearly the size of a dinner plate. With a simple (well established) triplet design there will be two more chunks of glass, nearly as large, right behind it. That will weigh a lot, and those large pieces of glass take longer to grind, so they cost more.

In contrast, a 400 mm f/4 would have 100 mm front lenses with 1/4 the surface area to grind, and potentially cost 1/4 the price of the previous example. But, for a few hundred dollars, one could add a 2x teleconverter and have an 800 mm f/8 lens. Are the extra 2 stops worth the added cost?

Adding a generic teleconverter provides image magnification, but it also magnifies any optical flaws from the main lens. In addition, an inexpensive converter probably isn’t as high quality as the original lens, so there may be additional quality loss.

Some lenses are sold with converters available that are matched to that particular focal length, and optimized for a given lens. These tend to give much better quality. The optical principles are the same as the less expensive converters; basically they just do a better job of grinding the glass and mounting it properly. Could this be a possibility for the 200-600 mm lens you speak of? Perhaps. Start a letter writing campaign to the manufacturer stating that you want one, and get a lot of friends to do the same. Then wait a few years. And good luck. If they see a market, they’ll make your lens. And charge you for it!

KillroyII Loc: Middle Georgia

When that comes out hopefully you will have a choice of which model truck it comes mounted on

cjc2 Loc: Hellertown PA

The size of the front element depends on the focal length, aperture, the exit element, overall optical design and format. Your physics is faulty, but you are on the right track. Best of luck.

flip1948 Loc: Hamden, CT

Yeah, sorry it was a 200-500 f/2.8 that came with a dedicated 2X teleconvertor making it a 400-1000mm f/5.6 zoom for $25,000.

It weighed 34.6 pounds and was introduced in 2008. It was built to order with a 4-6 week delivery time.

Papou Loc: Ottawa, Canada

Thank,s for your answer.

I didn't think there would be such a difference between the future 200-600 and one hypothical 300-800 lens. It,s all make sense. Regard
Eric

wdross Loc: Castle Rock, Colorado

Olympus/OMDS has a 300-800 angle of view lens with an extra 1.25 built-in teleconverter. If they can do it, so can everyone else.

Bill_de Loc: US

Your Sony has a very small lens, as you well know!

Sensor size 1/2.3" (6.17 x 4.55 mm)

---

Drbobcameraguy Loc: Eaton Ohio

Sigma has already built a 300-800mm f5.6 lens. I own one and love it. It is actually very sharp and very handy. Downside is a weight of almost 13lbs. It is great on my gimbal and my gitzo tripod. I paid 4300.00 usd used. I would not trade it for anything. Unfortunately these are low res pics from my phone but Google Bigma. That is it's nickname. It gets great reviews and you can cancel your gym membership. 😂

bnsf

Sony has a fixed 600mm lens for sale. Asking price $12,998.00 plus tax free shipping also. What price are they going to put on the 800 mm lens $15,000.00 and who has the large amount of money for just a lens you would use mabe a handful of times while it sets in the camera bag not being used. This would be a waste of money
But they do make a 200 - 400 lens for under $1,500.00 which would be a better deal in long run.

imagemeister Loc: mid east Florida

The Sony RX10m4 is much more palatable ......
.

flip1948 Loc: Hamden, CT

Sigma's 50-500mm zoom was called the Bigma.

I have seen the 300-800mm zoom called the Sigmonster.

Drbobcameraguy Loc: Eaton Ohio

Yes you are correct. Lol Sorry it was late. Either way it's a great lens.