# Why is there no 700mm?



## littlepilotdude (Oct 17, 2012)

Hello,

I am just wondering if anyone knows why there is no 700mm prime. Canon and Nikon both don't have one. 


Thanks,

littlepilotdude


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## SJTstudios (Oct 17, 2012)

700/1.4= 500
Canon 500mm f4 x 1.4= 700mm 5.6

This is one of the reasons canon puts a lot of mechanics in their TCs, because they want to give people different telephoto capabilities, without having to waste a lot of time, effort, and money on new prototypes.


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## dr croubie (Oct 17, 2012)

Also, the difference between 600-800mm is the same as the difference between 60-80mm.
There's a 60mm for EF-s, but for FF there's practically nothing between 50-85mm, a much bigger gap in percentage terms than the gap from 600-800mm.
Yes, there's zooms that cross that range, ie 24-70/2.8 and 24-105/4, but f/4 between 50-85mm is nowhere near the f/1.2 you can get at those lengths.
There's the Sigmonster zoom that crosses the 600-800mm at f/5.6, and the 800mm prime is f/5.6 too, any 700mm prime would be probably f/5.6 too. So when you think about it, if 601-799mm is the length you need, you're better served than if you need 61-79mm...


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## HawkinsT (Oct 17, 2012)

In how many situations do you really need a 700mm prime where neither a 600mm or 800mm will do?


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## Menace (Oct 17, 2012)

Market for 600mm+ lenses is rather small due manufacturing cost, RnD and materials all equates to relatively expensive lenses. 

I'm sure both Canon and Nikon would offer a 700mm lens if there was a profitable market for it but as it is, 500 with a 1.4x will get you there (as per SJTstudios) 

My 2 cents


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## dolina (Oct 17, 2012)

Not enough demand to create a 700mm.

500 = 10,500
600 = 13,000
800 = 13,900

My guess would be it will sell for about 12,000-13,000.


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## sandymandy (Oct 18, 2012)

Perhaps its also difficult to build. Ive heard 50mm is easy to build but 35mm is more difficult thats why there arent so many 35mm lenses with wide aperture out for example.


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## untitled10 (Oct 18, 2012)

sandymandy said:


> Perhaps its also difficult to build. Ive heard 50mm is easy to build but 35mm is more difficult thats why there arent so many 35mm lenses with wide aperture out for example.



That's because of the flange distance compared to focal length, 35mm is shorter than the 44mm flange distance and thus has to use a different lens type, but once you get over 200mm's or so then it just stays pretty much the same albeit larger, 700mm would be very slightly simpler than an 800 because you would need smaller fluorite elements to correct for chromatic aberration, that is the major problem with longer lenses and what makes all these so expensive, due to the Rn'D and expensive materials used to correct the difficult of a longer focal length.


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## sandymandy (Oct 18, 2012)

Thanks for the info.


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## preppyak (Oct 18, 2012)

untitled10 said:


> That's because of the flange distance compared to focal length, 35mm is shorter than the 44mm flange distance and thus has to use a different lens type, but once you get over 200mm's or so then it just stays pretty much the same albeit larger, 700mm would be very slightly simpler than an 800 because you would need smaller fluorite elements to correct for chromatic aberration, that is the major problem with longer lenses and what makes all these so expensive, due to the Rn'D and expensive materials used to correct the difficult of a longer focal length.


Yeah, my guess based on size and weight is that 600mm was as far as they could go with f/4, where a 700mm f/4 would weight 15lbs+ and just be too big for people to reasonably use. And while a 700mm f/5.6 would probably be lighter, the 800mm is only 9.9lbs, so, most would probably go for the reach over saving a few bucks at that price range. 

It's sort of in the same realm of why they don't offer a 1000mm or 1200mm lens (well, they do make a 1200mm, but, not for mortals). The return on investment isn't there, as it'd be too heavy, too expensive, and the alternatives with a 1.4x TC are just better. For example, the 1200mm f/5.6 they do make costs like $100k, which could buy you the entire EOS collection basically. Here is the 1200mm v the 800mm


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