It's in the lower costing 600 and 800 f11 lenses if I recall correctly. There's a patient for another lens, but who knows if that's going to make it to production.
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Canon RF Supertelephoto Lenses with built-in Extenders Appear in Latest Patent
- Thread starter Canon Rumors
- Start date
Possibly too niche but perhaps Canon could make a RF 300mm f/2.0 based on the RF 600mm f/4 with a builtin 1.4x extender which would make it a 420mm f/2.8 and if you added an external 1.4x extender it would be a 600mm f/4
Pretty versatile lens especially if it has a shortish minimum focus distance of about 2m and if the weight is less than 3.5kg
Ideally if possible a builtin 1.4x and 2x extender so you have 3 primes in one lens and presumably lighter than a 300-600 zoom and so much brighter on the wide end.
300mm f/2.0
420mm f/2.8
600mm f/4
Pretty versatile lens especially if it has a shortish minimum focus distance of about 2m and if the weight is less than 3.5kg
Ideally if possible a builtin 1.4x and 2x extender so you have 3 primes in one lens and presumably lighter than a 300-600 zoom and so much brighter on the wide end.
300mm f/2.0
420mm f/2.8
600mm f/4
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300 f2, must be tempting, but couldn't a traditional zoom design 300 to 600 f4 zoom be more marketable?
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The answer to your question (according to Copilot):BTW why are there no lenses with Carbon barrels, it’s light and it looks cool.
“Carbon fiber is indeed a fascinating material known for its lightweight and robust properties, but it hasn't become standard for photo lens barrels for several reasons:
1. **Precision and Stability**: Lens barrels need to maintain extremely tight tolerances for aligning optical elements. Metal, such as aluminum or magnesium alloys, is more stable and resistant to temperature fluctuations than carbon fiber, which can slightly expand or contract in changing conditions. This stability ensures optical performance.
2. **Manufacturing Complexities**: Carbon fiber is more challenging and costly to mold or machine into precise shapes compared to metals. The weaving process of carbon fiber also creates anisotropic properties, meaning its strength is not uniform in all directions, which can be problematic for lens designs.
3. **Durability and Rigidity**: Metals are better suited to handle impacts and wear-and-tear over time compared to carbon fiber, which can be susceptible to cracking or delaminating under stress.
4. **Cost**: Incorporating carbon fiber into lens barrels would significantly raise production costs, making the lenses less accessible to most photographers without offering proportional benefits.”
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I’ve read that the hoods for the ‘great white’ lenses are carbon fiber. Not sure if that’s true, and I’m not planning to cut mine open to find out.
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I always see that mentioned in the context of “why is a replacement $400?!?”, which makes me think they might not actually be CF, just priced to be what the market will bear
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Carbon fibre will fail catastrophically if you chip the edge of it which is why it's a really unsafe material for racing car wheels. If you bump the edge of the lens on any sharp point it will shatterWith DO lenses and Carbon barrel it might relatively light.
BTW why are there no lenses with Carbon barrels, it’s light and it looks cool.
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400mm f/2 would be too huge but 300mm f/2 would have same entrance pupil as a 600mm f/4
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A 300-600mm f/4 has only f/4 on the wide end but 300mm f/2 would be amazing on it's own with the option of flicking a switch to make it 420mm f/2.8 or 600mm f/4 (assuming it's feasible to make a lens with both 1.4x and 2x internal extenders).
Also a 300mm f/2 with these extenders builtin should be only slightly heavier than a 600mm f/4
There was a patent for a switchable 1.4x and 2x back in 2019: https://www.canonrumors.com/patent-switchable-1-4x-2-0x-teleconverter/
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I'd be very tempted by an ultra-lightweight 300mm f/2.8 but I can't see Canon producing one as they have the 100-300mm zoom. There's a surplus of used EF 300mm f/2.8 ii on sale here if you don't mind a heavier alternative.
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I'm suggesting a 300mm f/2.0 not f/2.8 and I found out Canon made a 300mm f/1.8 once: only 4 copies are known to exist and they were made for horse racing finishing cameras: https://petapixel.com/2017/04/27/canon-300mm-f1-8-yes-monster-lens-exists/
and even made a one off manual focus 400mm f/2.0: https://petapixel.com/2021/09/23/no-one-can-seem-to-identify-this-canon-400mm-f-2-lens/
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Suspended above the finishing line? Otherwise the nearer and further runners would disappear into the bokeh!
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Many, many years ago a New Zealand grad student told me the All Blacks trained by carrying a sheep under each arm. Presumably it was for holding these lenses?
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Sounds like an issue with that copy. I don’t notice an IQ hit at all in my copy when activating the 1.4x.
I know some IQ degradation happens, such is the case with any TC, but it’s not noticeable or worth worrying about with 45MP and typical post processing.
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Probably not as they would have the camera far enough away that the depth of field would cover the winning group okay (remember the horses would be very close together at the finish rather than spread across the course).
For example at 30m the depth of field is over a meter
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