Here is the Canon Cinema EOS C70

HarryFilm

EOS RP
Jun 6, 2016
718
171
How does the material of the lens affect the diffraction limits - the diffraction limit is caused by the ring of material around the lens?


Optical-grade Acrylic has a much higher index of refraction than fluorite glass which means alignment of lens elements needs to be more precise once you get above the 2+ metre threshold for the diameter of individual lens elements so that chromatic aberation doesn't occur (I'm not an optical scientist so my understanding is somewhat limited!). You're trying to PREVENT the spread of light-rays into areas where they shouldn't be going within a given lens and sensor assembly!

The parent company uses electro-hydraulics-based adaptive optics where lens elements are moved by a series of electric + hydraulic motors as fast as 300 movements per second to align the lenses for perfect imagery for elements that ARE LARGER THAN TWO METRES ACROSS. It also functions as a very large IBIS-like optical stabilization system IN ADDITION to having the entire assembly set on a 6-axis gimbal to counter the effects of orbital wobble!

That's WHY we can get 3 cm per pixel resolution because the incoming light waves are mapped by computer to specific areas of a sensor and computational photography principles ESTIMATE which parts of an image will receive how much light in what specific visible band of EM (i.e. using ray-tracing techniques) and this is done as fast as 300 calculations per second per mapped arc-degree on any given lens element. That means a total of TENS OF BILLIONS of floating point operations per second for all the lens elements combined! We actually put up a rad-hardened supercomputer system in-orbit to be able to do those calculations in real-time for auto-correction of pixel-level aberations!

Again, I'm not the optical physicist, so I can only go by what I read in our lens assembly manuals and this thing is the size of a transit bus! It's one of the more MASSIVE human-made objects in space. Bigger than the Gambit/Misty NRO satellites! Its very eccentric orbit makes it hard to spot but the upper one is Polar Orbit so it shouldn't be too hard to see in North America!

And NO I don't have it's specific orbital coordinates -- It's not a classified system but I think for commercial reason has more to do with keeping its long term weather projection abilities secret! Evidently, high end imaging systems combined with supercomputers combined with year-over-year weather and crop-growth statistics creates VERY VALUABLE WEATHER PREDICTION DATA that is used in financial markets-oriented commodity food and petroleum products options and futures purchases and sales/resales on the order of 10 or 11 digit levels per year! The licencing of that weather-related data makes for some significant income for the parent company.

P.S. This year's prediction is very dry out west for most of the year with not as much snow for the ski mountains (La Nina effects!) except for week-long bursts of precipitation that will occur sporadically but with great intensity. This means it will be mostly cooler and dryer in the pacific northwest with some short-term but intense Rainageddons in Seattle/Vancouver in November 2020 to February 2021 and several short-term Snowmaggedons in the Eastern Rockies (i.e. Denver, Colorado and Calgary, Alberta) about once every 6 to 8 weeks for the October 2020 to April 2021 period! Skiing on the west coast won't be as good as last year but the Rockies should be fine for winter snow.

The upper prairies into Canada will be colder and dryer than last year but the east coast will be dumped on rain-wise and sleet-wise. California will be especially dry with little rain but moderately cooler or warmer temperatures than last year. The lower west coast California could be 1.5 to even 2 degrees up or down from last year on average due to La Nina-related effects. South will be almost identical to last year maybe a tiny-bit dryer and cooler. The southeast (Florida and nearby states) is always harder to predict due to the water vapour uprise effects prevalent in the Virginias and Carolinas where this winter is a toss-up between Snowmageddon, Stormageddon or Sunny or all-three. I wouldn't be surprised to see some intense frost in upper Florida this year wrecking havoc on the Orange crop for 2021! (Don't blame me if all the above is completely wrong though -- it's only a limited but reasonable estimation!)

V
 
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AlanF

Stay at home
CR Pro
Aug 16, 2012
8,890
12,202
Optical-grade Acrylic has a much higher index of refraction than fluorite glass which means alignment of lens elements needs to be more precise once you get above the 2+ metre threshold for the diameter of individual lens elements so that chromatic aberation doesn't occur (I'm not an optical scientist so my understanding is somewhat limited!). You're trying to PREVENT the spread of light-rays into areas where they shouldn't be going within a given lens and sensor assembly!

The parent company uses electro-hydraulics-based adaptive optics where lens elements are moved by a series of electric + hydraulic motors as fast as 300 movements per second to align the lenses for perfect imagery for elements that ARE LARGER THAN TWO METRES ACROSS. It also functions as a very large IBIS-like optical stabilization system IN ADDITION to having the entire assembly set on a 6-axis gimbal to counter the effects of orbital wobble!

That's WHY we can get 3 cm per pixel resolution because the incoming light waves are mapped by computer to specific areas of a sensor and computational photography principles ESTIMATE which parts of an image will receive how much light in what specific visible band of EM (i.e. using ray-tracing techniques) and this is done as fast as 300 calculations per second per mapped arc-degree on any given lens element. That means a total of TENS OF BILLIONS of floating point operations per second for all the lens elements combined! We actually put up a rad-hardened supercomputer system in-orbit to be able to do those calculations in real-time for auto-correction of pixel-level aberations!

Again, I'm not the optical physicist, so I can only go by what I read in our lens assembly manuals and this thing is the size of a transit bus! It's one of the more MASSIVE human-made objects in space. Bigger than the Gambit/Misty NRO satellites! Its very eccentric orbit makes it hard to spot but the upper one is Polar Orbit so it shouldn't be too hard to see in North America!

And NO I don't have it's specific orbital coordinates -- It's not a classified system but I think for commercial reason has more to do with keeping its long term weather projection abilities secret! Evidently, high end imaging systems combined with supercomputers combined with year-over-year weather and crop-growth statistics creates VERY VALUABLE WEATHER PREDICITION DATA that is used in financial markets-oriented commodity products options and futures purchases and sales/resales on the order of 10 or 11 digit levels per year! The licencing of that weather-related data makes for some significant income for the parent company.

V
OK, you are using lenses of greater than 2m diameter, which you can make with acrylic not fluorite. For our purposes, that would mean a lens considerably higher and wider than most CR members. I suppose such a lens would enforce 2m social distancing for side-by-side photographers.
 

HarryFilm

EOS RP
Jun 6, 2016
718
171
OK, you are using lenses of greater than 2m diameter, which you can make with acrylic not fluorite. For our purposes, that would mean a lens considerably higher and wider than most CR members. I suppose such a lens would enforce 2m social distancing for side-by-side photographers.

---

YUP! They're pretty big lenses but not outrageously large. SOME elements I have hear about in the more "Black Budget World" use refractive-based and mirror-based optical assemblies that are THREE metres in diameter! I only know about the publicly disclosed systems like Gambit/Misty but systems like the "Future Optics and Imaging System" that has been on the drawing board since 2010, has PROBABLY already been deployed which means that much larger lens and sensor assemblies than our two metre one!

We use a single very-large custom-built 400mm CMOS sensor while the newer mil-spec systems use ARRAYS of multiple smaller sensors to get the equivalent of multi-gigapixel imagery. The mil-spec systems also have the equivalent of Gigabit Ethernet in space while we are restricted to between 10 to 20 megabits per second image download speeds due to the high orbit and various no-Microwave/RF-interference pacts made between the parent company and other countries for keeping various communications bands clear during most of the working day.

V
 
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SteveC

R5
CR Pro
Sep 3, 2019
2,481
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OK, you are using lenses of greater than 2m diameter, which you can make with acrylic not fluorite. For our purposes, that would mean a lens considerably higher and wider than most CR members. I suppose such a lens would enforce 2m social distancing for side-by-side photographers.

Don't make the mistake of believing anything he says.
 

SteveC

R5
CR Pro
Sep 3, 2019
2,481
2,346
According to dpr the world's largest lens is 1.57m wide, which is indeed less than the 2m lenses from Harry's company https://www.dpreview.com/news/70795...ered-for-massive-3-2-gigapixel-digital-camera
But, we don't believe dpr here, do we?

It was a gigantic accomplishment (for its day) to produce a 40 inch objective for the world's largest refractor.

Anything bigger than that tends to sag under its own weight (though that's less of an issue when the lens is oriented to take pictures of stuff on the horizon).
 

HarryFilm

EOS RP
Jun 6, 2016
718
171
According to dpr the world's largest lens is 1.57m wide, which is indeed less than the 2m lenses from Harry's company https://www.dpreview.com/news/70795...ered-for-massive-3-2-gigapixel-digital-camera
But, we don't believe dpr here, do we?


===

When BACKYARD HOBBYISTS are making 70 inch (1.7 metres) reflector (i.e. mirrored) telescopes, I think a firm that is literally a BILLION+ DOLLAR AEROSPACE COMPANY can afford to CNC machine some huge blocks of optical grade acrylic into a decent set of lenses within one of the twenty-plus, high-precision 3000 mm by 3000 mm by 3000 mm volume 5-axis CNC machines it has in it's warehouses!


Acrylic actually does seem to have less sag than fluorite due to its much lighter weight and in space this sag is a NON-ISSUE anyways where the larger issue is embrittlement, degradation and yellowing caused by solar radiation where specialized thin-film coatings are necessary to protect a plastic lens in space or on the ground.

Acrylic's high thermal expansion/contraction indexes do make it difficult to use as an actual lens element without adaptive optics and computational photography processing (i.e. IBIS and DSP) to ensure proper image sensing BUT because of modern computer abilities, this is now no longer a problem and can even be used in pro-level and consumer camera lenses if good firmware is embedded into a camera with appropriate computational photography algorithms that do a bit of post-picture raytracing computation along a lens light path.

The higher refractive index (1.55) of Acrylic vs 1.43 of Fluorite Glass makes for better optics which is WHY a two metre diameter set of lens elements floated upon electro-hydraulic rams with imagery processed by a multi-TeraFLOP set of combined CPU/GPU/DSP superchips can obtain a 3 cm per pixel resolution while in a 1500 km high orbit!

There are physical resolution limits that NORMALLY restrict such a 2 metre refractor telescope setup to about 15 cm per pixel BUT with modern raytracing and computational photography the calculated/perceived resolution obtained by software trickery is now 3 cm per pixel.

===

NOW ..... If Canon, SIGMA and SONY were to REPLACE the interior and outer lens elements of their major prime and zoom lenses with coated Acrylic plastic, that RF-mount 50mm prime lens at f/1.2 that sells for $2199 USD:


would become an f/0.95 50mm NOCTO prime lens that could be made for HALF-THE-COST (i.e. sold for $1100 USD) and the only thing that needs to be done is an aluminum oxide/corundum thin-film sputtered coating that will create a scratch-proof surface for such plastic lens elements and some internal light path estimation, raytracing plus pixel-value re-mapping firmware added to the camera bodies!

If I were Canon, SIGMA and SONY, I would be looking at making a SEPARATE LINE of thin-film corundum/aluminum oxide-coated optical-grade high-refractive index Acrylic lenses that offer 1 to 2 stops FASTER than normal glass at HALF the weight!

Call them Nocto-Feather Prime Lenses or something like that as a brand (i.e. FAST and LIGHT AS A FEATHER!)

Hmmmm... that also means SIGMA could make a practical and LIGHT WEIGHT 135 mm-to-650 mm SPORTS ZOOM lens that is f/2.8 to f/4 which would be a SUPER-FAST zoom lens! Great for sports and action photography!

V

Thin Film Coated Optical Grade Acrylic Lens Elements!






IT'S THE FUTURE OF FAST LIGHT WEIGHT PRIME AND ZOOM LENS TECHNOLOGY !!!

V
 
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mariosk1gr

EOS M6 Mark II
Jan 4, 2019
87
65
With C300 Mark III DGO sensor, C70 will be an amazing camera for gimbal use, crash cam and as a b-cam in combo with its bigger brothers (c300/c500). As Komodo in 1st place was manufactured as a crash cam in mind while Hollywood was forced to use GoPros in situations with explosions, action movies, chasing cars etc. If c70 has similar dimensions as Komodo then it could fit in high end productions. For me IBIS on this camera is not a necessary thing. One thing that I feel that Canon need to provide is a better raw codec option with higher bitrate and different compressions to choose. RED Raw has the advantage there and Braw is following very closely. Canon needs to catch up there. If you have seen CineD dynamic range of the R5 for example you can see that there are 2 additional stops buried in the shadows while shooting 8k raw. With a much more efficient raw codec with different compression methods and 16-bit raw, there is an opportunity to bring these stops back with not so much noise and banding. DGO sensor has proven already its strength and capabilities ( a technology that is already present in Arri cameras for a long time). SDI from the other hand is imo a huge missing from c70.