Canon announces development of the EOS R5 full-frame mirrorless camera

Hello,
and thanks for sharing further details!
While I am not familiar with the technique, I have some general questions/remarks:
You quote a CNC precision of "0.0005 of a millimetre". This is 500 nano meters. I know that highly even surfaces like lensess/mirrors have: Their surface is even to a few atomic layers which amounts to 10 nano meter and below. So, there is still a factor of 50x between this and the 500 nano meter a CNC can do.
My point: Still, a polishing step would be needed. And each of those steps is costly. At the, I am not sure how much the cost advantage would be?
I do understsnd that weight is a big advantage on its own that could justify such lenses.

YES automated polishing would STILL be needed BUT it is a lot easier to polish polycarbonate or acrylic that fluorite glasses! Since the polymer lenses could be made by teh hundreds using CNC machined blanks of 10 by 10 or 20 by 20 lens elements, it would be FAST to produce many lenses so the time factor alone would make the fine polishing step a non-issue as that too would be faster than glass!

The weight advantage BY FAR is a the greatest selling point ESPECIALLY for Zoom Lenses! It means I could make a 95-800mm f/4.0-f/5.0 Sports Zoom Lens in the same length and size as the current Sigma 150-600mm f5-6.3 zoom lens


AND it would still be 30% to 50% LIGHTER than the current Sigma Sports Zoom!

i.e. it would weigh only 3.1 pounds (1450 grams) versus 6.3 lb/2860 g

I am pretty sure MANY photographers would pay a small premium to buy such a zoom lens that has more reach, is much FASTER and is much lighter!

Can you say ??? .... Put it on my Visa/Mastercard/Amex RIGHT OW !!!!!

.
 
Upvote 0

AlanF

Desperately seeking birds
CR Pro
Aug 16, 2012
12,355
22,528
I know you're being SOMEWHAT sarcastic .... BUT .... Al2O3 (Alumina aka Sapphire) is REALLY CHEAP these days !!!

Up here in Canada, I can buy Alumina powder by the 15 Tonne truckload for dirt cheap from ALCAN and turn it into a nice sputtered/vapourous clear ceramic lens coating with but the addition of some cheap chemicals, simple heat and a vacuum chamber! Carbon Allotrope (aka Diamond) is EXTREMELY difficult to make properly without very expensive anvils and high pressures and the Diamond coating vapour deposition process is STILL patented by a company in Florida at a rather expensive royalty rate! So Sapphire it must be! Plus, Sapphire can withstand up to 2000 degrees Celcius which is MUCH better than Diamond's 700 degrees Celcius with nearly the same scratch resistance!

Again, if a company LIKE SIGMA could make PLASTIC R-mount lenses out of Polycarbonate or Acrylic and Sapphire-coat them, they would be f/1.0 prime lenses at HALF-the-weight and 10% to 20% cheaper to make than their CURRENT Sigma Art Series Prime and Zoom lenses.

I would LOOOOOOOOOVE to have the Sigma 150 to 600mm Sports Zoom to be f/4.0-to-f/5.0 OR EVEN FASTER and have it weigh 50% less than the current one! I would buy it the VERY DAY it came on the market! In FACT, with the high refractive index of thin film Sapphire-coated Polycarbonate (i.e. higher than glass!), we could have a 95 to 800mm Sports Zoom at f4.0 to f/5.6 that is LIGHTER and shorter than today's Sigma 150-to-600 mm sports zoom! I would DEFINITELY pay a premium for that lens!!!!! (Hmmm....not too much of a premium Sigma !!! ...but a nice profitable enough premium for Sigma IF they can pull it off!!! --- And I KNOW THEY CAN !!!! )
Harry, I follow up things that seem interesting. There is a problem with the high refractive index of thin film sapphire, it is a disadvantage - high refractive index leads to high reflection, about 14%, which makes it unsuitable used raw. It has to be coated with HfO2, which reduces its reflectivity to 1.3%. That still seems high to me for a series of elements in a multi-element lens.
 
Upvote 0
Harry, I follow up things that seem interesting. There is a problem with the high refractive index of thin film sapphire, it is a disadvantage - high refractive index leads to high reflection, about 14%, which makes it unsuitable used raw. It has to be coated with HfO2, which reduces its reflectivity to 1.3%. That still seems high to me for a series of elements in a multi-element lens.

We call OUR solution an Add-on Circular or Linear Polarizer filter!

That reduces reflectivity by quite a nice amount and it can be used as a sacrificial front element protector on such Sapphire-coated polycarbonate lens systems. I'm going to suggest that Hafnium Dioxide is a tad rather expensive compared to Indium Tin Oxide which would used as a sapphire SURFACE COATING instead of being diffused into the thin-film Sapphire like the HfO2 would likely be.

Since modern optics design software can MEASURE and predict the optical pathways including the corrections of and/or the waveguiding of reflections, you can get PROBABLY get away with using anti-reflective coatings ONLY on the first front and last back plastic lens element and then using a sacrificial polarizer filter on the front of the lens, which many photographers use anyways, to protect those organic anti-reflective coatings!

Again, I am only "lightly educated" when it comes to organic chemistry and metallurgy BUT I think I can say that organic surface coatings ON thin-film Sapphire covered by a removable $50 to $100 polarizer will work wonders! Possible LASER ETCHING a polarizer filter onto the sapphire thin film MAY also help with reflectivity! I'm not an optics designer, so I cannot say if THAT would work BUT it's a start for SIGMA and/or Canon to read up on and then TEST out my suggestions in a proper lab setting!

.
 
Upvote 0

AlanF

Desperately seeking birds
CR Pro
Aug 16, 2012
12,355
22,528
We call OUR solution an Add-on Circular or Linear Polarizer filter!

That reduces reflectivity by quite a nice amount and it can be used as a sacrificial front element protector on such Sapphire-coated polycarbonate lens systems. I'm going to suggest that Hafnium Dioxide is a tad rather expensive compared to Indium Tin Oxide which would used as a sapphire SURFACE COATING instead of being diffused into the thin-film Sapphire like the HfO2 would likely be.

Since modern optics design software can MEASURE and predict the optical pathways including the corrections of and/or the waveguiding of reflections, you can get PROBABLY get away with using anti-reflective coatings ONLY on the first front and last back plastic lens element and then using a sacrificial polarizer filter on the front of the lens, which many photographers use anyways, to protect those organic anti-reflective coatings!

Again, I am only "lightly educated" when it comes to organic chemistry and metallurgy BUT I think I can say that organic surface coatings ON thin-film Sapphire covered by a removable $50 to $100 polarizer will work wonders! Possible LASER ETCHING a polarizer filter onto the sapphire thin film MAY also help with reflectivity! I'm not an optics designer, so I cannot say if THAT would work BUT it's a start for SIGMA and/or Canon to read up on and then TEST out my suggestions in a proper lab setting!
"We call OUR solution an Add-on Circular or Linear Polarizer filter!" shows you clearly have gone into this in some depth as sapphire is birefringent and will polarise light. Moulded plastic lenses were used decades ago in the cheapest cameras, and some current lenses do have cheap moulded elements. So, Sigma etc must surely have tried using plastics more generally?
 
Upvote 0
"We call OUR solution an Add-on Circular or Linear Polarizer filter!" shows you clearly have gone into this in some depth as sapphire is birefringent and will polarise light. Moulded plastic lenses were used decades ago in the cheapest cameras, and some current lenses do have cheap moulded elements. So, Sigma etc must surely have tried using plastics more generally?

I never said I was a Materials Expert! I actually DID NOT KNOW that Sapphire has TWO DIFFERENT indexes of refraction! (learn something new every day!)

For those who want to know more about birefringence:


My ORIGINAL suggestion was to use thin-film Sapphire over Polycarbonate/Acrylic mostly as an ANTI-SCRATCH material. I should note however, the birefringence issue has to do with the non-cubic structural nature of the sapphire itself and I am not at all sure that a micron-thin coating (1 or 2 microns) is really enough to refract the incoming light rays so much so that the 0.008 difference in indices could not be corrected by other means of which I am as of yet unfamiliar. (i.e. a rotated micro-etching on the back side of a coated plastic element perhaps?)

This means (unfortunately rather time consuming at this time to do!) that laser etching could correct this:

Controlling material birefringence in sapphire via self-assembled, sub-wavelength defects
(using laser etching)


ABSTRACT:
Birefringence is the optical property of a material having a refractive index that depends on the polarization and propagation direction of light. Generally, this is an intrinsic optical property of a material and cannot be altered. Here, we report a novel technique—direct laser writing—that enables us to control the natural, material birefringence of sapphire over a broad range of wavelengths. The broadband form birefringence originating from self-assembled, periodic array of sub-wavelength (∼ 50–200 nm) defects created by laser writing, can enhance, suppress or maintain the material birefringence of sapphire without affecting its transparency range in visible or its surface quality.

This below KEY SENTENCE seems to indicate my earlier suggestion to use laser etching on thin film coatings MAY be a viable option!

"...... periodic array of sub-wavelength (∼ 50–200 nm) defects created by laser writing, can enhance, suppress or maintain the material birefringence of sapphire without affecting its transparency range in visible or its surface quality."

This type of materials science is getting in the realm of "Metamaterials" waveguiding and waveform shaping which is QUITE EXPENSIVE to do, so we may have to keep the anti-scratch coatings REALLY THIN and/or microetch the main plastic lens elements themselves as a sort of Waveform Pre-distortion which will re-twist/bend/refract lighwaves back into the direction we want.

I am QUITE SURE all this can be simulated on any major optics-oriented ray-tracing software to TEST what types of etchings would work to INEXPENSIVELY allow plastic lens to function as high-performance profession-grade still photo and cinema lens elements even with all the anti-scratch coatings, polarizers, anti-reflective agents, optical notch filtering, etc. applied to said lenses!

.
 
Upvote 0
Hi Harry.
Just asking as my scientific knowledge is limited, but can this (CPL) be done without throwing away 1/2 to 1 stop of light? We all seem to always be fighting higher ISO’s!

Cheers, Graham.

By CPL I am assuming you mean Circular Polarizer?

Now that I know the Sapphire has TWO difference refraction indices (birefringent), some micro-etching WILL need to be done of both sides of a lens element OR some rather time-consuming and INTENTIONAL light-shaping/waveguiding-like defect introduction (i.e. expensive!) will need to be performed!

No matter WHAT is done, the light loss will be a MINIMUM of 1/2 of a stop! BUT since Polycarbonate/Acrylic is VERY EASY to machine, polish and shape to ANY aspherical and compound curve shape I am QUITE SURE that f/1.0 or f/1.2 is achievable for an inexpensive set of prime lenses and that even zoom lenses WILL be much faster than they currently are if we move over to polycarbonate/acrylic!

.
Again, it is the anti-scratch, glass-creep and plastic formula stabilization issues that will need addressing BUT SIGMA and Canon DEFINITELY HAVE the research muscle to make it happen! I have outlined in previous posts WHERE to start to make SUPER FAST consumer friendly lenses in plastic. They just need to COMMIT to doing it!

Having a SUPER SHARP and SUPER FAST beyond Zeiss Otus image-quality-level of f/1.0 35mm, 50mm and 85 mm prime for $900 US instead of $4500 US would REALLY make my day!

.
.
 
Upvote 0
What is CR coming to?:sleep: Guess it's just the result of substantive rumours followed by nothing. I want more rumours with more specs!:)
Jack

---


I think you want THIS RUMOUR BELOW:

FINAL SPECIFICATIONS for Medium Format Sensor 8K/50.3 Megapixel Combined Stills/Video Global Shutter Mirrorless Camera !!!!


---

REMEMBER! You Heard it Here First !!!!!!!!!!

---
 
Upvote 0

Jack Douglas

CR for the Humour
Apr 10, 2013
6,980
2,602
Alberta, Canada
---


I think you want THIS RUMOUR BELOW:

FINAL SPECIFICATIONS for Medium Format Sensor 8K/50.3 Megapixel Combined Stills/Video Global Shutter Mirrorless Camera !!!!


---

REMEMBER! You Heard it Here First !!!!!!!!!!

---

NO, NO, NO, I want Canon rumours! R5 rumours and ...:mad:

Jack
 
Upvote 0
It’s not a “compromise” if it’s the limit of what can be achieved now. And of course, you are free to buy whatever uncompromised 8k body the competition is offering, though I’m not sure what that is.
I would rather have a ridiculously good 4K body than take a compromised 8K body producing files that is computationally intensive. If 8K was really prevalent it would have been a different issue. I would prefer a matured tech rather than a high spec sheet which is unfinished.
 
Upvote 0

telemaque

Before Sunset
CR Pro
Nov 30, 2019
121
77
---

Originally, Polycarbonate and Acrylic have been used in Eyeglasses/Sunglasses production.

Further information about such uses is below:



but for computer and video imaging application LITTLE has been done except in Infrared (thermal) imaging applications for reasons outlines below which are an illustration of the TRADITIONAL PROBLEMS of using polymer lenses in video, still photo and telescope applications:


Lens Power and Chromatic Aberration:

HOWEVER, today in 2020 it actually IS POSSIBLE to make a typical still photo and video-centric optical lens for use on consumer and professional grade video and still photo cameras since much research and NEW FIXES for those traditional manufacturing and coating issues is now available from such places as GS Optics, Edmunds Scientific and many others:




Plastic Lenses REQUIRE anti-scratch coatings:


Good Technical Book to Read:
Handbook of Optomechanical Engineering


If you want to BUY Molded Acrylic Aspheric lenses:


For Short Wave Infrared Imaging purposes someone has decided PLASTIC LENSES are good enough!

Antireflection Coatings Make Plastic Lenses “Disappear”




Precision CNC Machining Polymer Lenses:


The key part is while there is ACTIVE RESEARCH into cinema camera-grade optics, there is NOT YET a viable product being sold in the general marketplace. However, if Canon OR Sigma wish to do so, it is EASILY done by their optics teams who DO HAVE the technical expertise to make FAST lenses made of polycarbonate and/or acrylic happen!

Waow this should be sufficient information for most people.
I see I have a lot to read;

Thanks Harry.
 
Upvote 0
"EOS Zeus" saw this popup when registering for EOS R5 info on the Canon UK website https://www.canon.co.uk/cameras/eos-r5/

S6ymC2b.png
 
Upvote 0