Canon Patent Application: Canon RF 56mm F1.2

[Maximilian]

...my initial reaction is oh...gausian optics! ...

I really would like to see, what modern simulation programs, new glass materials and latest coatings can get out of this "vintage" formula.
An EF/RF 50/1.2 never came to my mind as a (hobbyists) tool. Apart from the price, they're just too big and heavy for universal use.
Too much of a specialist.
And I would be happy with an f/1.4 here as well, as long as I could also well use it from f/1.4 on.

 

[GMCPhotographics]

I really would like to see, what modern simulation programs, new glass materials and latest coatings can get out of this "vintage" formula.
An EF/RF 50/1.2 never came to my mind as a (hobbyists) tool. Apart from the price, they're just too big and heavy for universal use.
Too much of a specialist.
And I would be happy with an f/1.4 here as well, as long as I could also well use it from f/1.4 on.

I used to shoot a lot of weddings professionally and I had a bag full of EF primes and EF f2.8 zooms. I'm intimately familiar with all of them, the EF 50mm f1.2 L is a curious lens. The Af was the most inconsistent and ponderous that I've seen from any modern Canon lens (zoom or prime). People often compain about the EF 85mm f1.2 II L's AF, but it's far superior to the EF 50mm f1.2. In low light it just got worse, even the EF 24-70mm f2.8 mk1 was faster and more accurate and that was 2 stops darker. The EF 50mm F1.2 L was pricey (although S/H they seem to ahve taken a tumble) and a nice weight and size (compared to other L primes). I've owned three copies and Post Prodded the files from two others and I've never found one that was particularly sharp, even stopped down. Nice rendering and great colours and contrast, but not a particularly sharp lens.

 

[Sporgon]

Yeah, but it will be Dreamy.

Did you get that for the Nikon spec sheet ?!
Actually, as @Maximilian says, given how Canon were able to improve the performance of the likes of EF 50/1.8 & RF through efficient build and coatings, it could be an interesting lens. I wish Canon had given the EF 50/1.4 this treatment, as despite the venom directed at it here, it is actually one of the few lenses that can match ultra modern, sharp lenses across the frame, such as the EF 35/1.4II at apertures from about f/4 onwards.

 

[Sporgon]

I used to shoot a lot of weddings professionally and I had a bag full of EF primes and EF f2.8 zooms. I'm intimately familiar with all of them, the EF 50mm f1.2 L is a curious lens. The Af was the most inconsistent and ponderous that I've seen from any modern Canon lens (zoom or prime). People often compain about the EF 85mm f1.2 II L's AF, but it's far superior to the EF 50mm f1.2. In low light it just got worse, even the EF 24-70mm f2.8 mk1 was faster and more accurate and that was 2 stops darker. The EF 50mm F1.2 L was pricey (although S/H they seem to ahve taken a tumble) and a nice weight and size (compared to other L primes). I've owned three copies and Post Prodded the files from two others and I've never found one that was particularly sharp, even stopped down. Nice rendering and great colours and contrast, but not a particularly sharp lens.

If you look back at lenses that have been admired over the years for their “rendering” I think they are often lenses that exaggerate the bokeh by being poor resolution off centre. This requires the subject to be in the centre of course. Also, these (roughly standard focal length) lenses that aren’t razor sharp don’t over exaggerate the subject separation. When I first saw images from the likes of Sigma 35 / 50 Art, Otus etc shot wide open, my first reaction was that the images looked like a montage, one image sharp superimposed on a blurred one. This trend grows, and personally I don’t think it looks natural. I’m guessing this proposed lens would give a more traditional look.

 

[davision]

As @neuroanatomist already stated, it is FF.
For a better explanation, see this graphic below.

View attachment 211625

Okay thank you for the lesson

I just really wonder who made this up since thats not the image hight, it's the half image hight.

 

[EricN]

Okay thank you for the lesson

I just really wonder who made this up since thats not the image hight, it's the half image hight.

I think it is referring to radius versus diameter.

 

[Loswr]

I think it is referring to radius versus diameter.

Since an image circle is symmetrical, a patent specifies the parameters for just half of it. Radius, half angle of view, all of the described optical curvatures, etc.

 

[jd7]

If you look back at lenses that have been admired over the years for their “rendering” I think they are often lenses that exaggerate the bokeh by being poor resolution off centre. This requires the subject to be in the centre of course. Also, these (roughly standard focal length) lenses that aren’t razor sharp don’t over exaggerate the subject separation. When I first saw images from the likes of Sigma 35 / 50 Art, Otus etc shot wide open, my first reaction was that the images looked like a montage, one image sharp superimposed on a blurred one. This trend grows, and personally I don’t think it looks natural. I’m guessing this proposed lens would give a more traditional look.

I agree about the newer, sharper, lenses creating images which have a tendency to look like a montage when shot at wide aperture. I recall people complaining about the "sticker effect" of the original Sigma 35 and 50 Art lenses, but I think it was just a consequence of the increased sharpness of those lenses compared to many other lenses of the time. And as you say, it was not just a Sigma thing, and it has become fairly common with most newer lenses, or at least high end lenses. In fact, I think it happned even with older lenses if the image had the "wrong" composition and lighting (generally I find that background in the middle to far distance, and a rougly uniform distance behind the subject, tends to exaggerate the montage effect and it is even more pronounced if the subject and background have significantly different brightness), including even with older lenses lauded for their renderring, such as the EF 135L. However, the additional sharpness of many lenses tends to make the edge of the subject that much more clearly defined and that tends to exaggerate the effect, so you have to be that much more careful with composition and lighting. Any lens which aren't sharp by today's standards have a tendency to produce the montage effect generally gets poorly reviewed on the internet though (eg reviews of the Sigma 45mm f/2.8 often complain about it lacking sharpness albeit it has developed something of a cult following as well - and no, that lens is not available in EF or RF mount), so my bet is we will not see too many new lenses which buck the trend.

 

[David - Sydney]

Would this be a Canon "surprise" lens and negate the need for a RF50/1.4? ie mid priced?

 

[Tom W]

I find this kind of interesting - a 56/1.2 with similar design to the EF 50/1.2 or the EF 50/1.4. Presumably with newer design and assembly tech, I could see this as a nice fit in between the 50/1.8 and the RF 50/1.2L. The characteristics of the 50/1.2 - the smooth bokeh and almost dreamy look at times - would be an asset to many.

BTW, I have the 50/1.2L EF version and it focuses excellently with the R5. Its AF issues go away with the on-sensor focusing scheme in the mirrorless bodies.

 

[Maximilian]

I just really wonder who made this up since thats not the image hight, it's the half image hight.

Seems odd somehow, I agree, but neuro gave the answer: it's all about symmetry.

Since an image circle is symmetrical, a patent specifies the parameters for just half of it. Radius, half angle of view, all of the described optical curvatures, etc.

 

[GMCPhotographics]

I find this kind of interesting - a 56/1.2 with similar design to the EF 50/1.2 or the EF 50/1.4. Presumably with newer design and assembly tech, I could see this as a nice fit in between the 50/1.8 and the RF 50/1.2L. The characteristics of the 50/1.2 - the smooth bokeh and almost dreamy look at times - would be an asset to many.

BTW, I have the 50/1.2L EF version and it focuses excellently with the R5. Its AF issues go away with the on-sensor focusing scheme in the mirrorless bodies.

However, the sensor based AF can’t fix the aperture related focus shift at f2.8 that is inherent to the EF 50mm f1.2L’s optical design.
Yes the wide open AF performance is greatly improved by the newer camera bodies. But the lens still retains some issues.

 

[koenkooi]

However, the sensor based AF can’t fix the aperture related focus shift at f2.8 that is inherent to the EF 50mm f1.2L’s optical design.
Yes the wide open AF performance is greatly improved by the newer camera bodies. But the lens still retains some issues.

But focus shift is consistent and repeatable, counteracting that is something computers excel at. It could be a simple as measuring the effects and using a 2D look up table to adjust the focus during exposure.
Judging from the RF100L release, Canon was more interested in moving the focus motors independently for artistic effect than adjusting for focus shift. So fixing focus shift in software doesn't seem to be a priority for Canon.

 

[Sporgon]

But focus shift is consistent and repeatable, counteracting that is something computers excel at. It could be a simple as measuring the effects and using a 2D look up table to adjust the focus during exposure.
Judging from the RF100L release, Canon was more interested in moving the focus motors independently for artistic effect than adjusting for focus shift. So fixing focus shift in software doesn't seem to be a priority for Canon.

Agreed. I believe that Hasselblad uses computation to correct for focus error when using centre point to focus and recompose.
Or maybe program to stop down when focusing at the more focus shift apparent apertures.
The EF 24-70 f/4 IS has some issues with focus shift. I was really surprised to see the difference in sharpness when carefully manually focusing in magnified live view with the lens stopped down, compared to focusing in the normal open aperture method. On the 5DS the lens goes from acceptable to excellent. Obviously this is only practical for landscape photography and the like, but like you say, Canon don’t seem to give it any time. Probably because 99.9% of users don’t notice.

 

[EricN]

Agreed. I believe that Hasselblad uses computation to correct for focus error when using centre point to focus and recompose.
Or maybe program to stop down when focusing at the more focus shift apparent apertures.
The EF 24-70 f/4 IS has some issues with focus shift. I was really surprised to see the difference in sharpness when carefully manually focusing in magnified live view with the lens stopped down, compared to focusing in the normal open aperture method. On the 5DS the lens goes from acceptable to excellent. Obviously this is only practical for landscape photography and the like, but like you say, Canon don’t seem to give it any time. Probably because 99.9% of users don’t notice.

It would be interesting if we could ask and get an answer about Canon's reasoning here. Anyway, thanks for pointing out about this method!

 

[GMCPhotographics]

If you look back at lenses that have been admired over the years for their “rendering” I think they are often lenses that exaggerate the bokeh by being poor resolution off centre. This requires the subject to be in the centre of course. Also, these (roughly standard focal length) lenses that aren’t razor sharp don’t over exaggerate the subject separation. When I first saw images from the likes of Sigma 35 / 50 Art, Otus etc shot wide open, my first reaction was that the images looked like a montage, one image sharp superimposed on a blurred one. This trend grows, and personally I don’t think it looks natural. I’m guessing this proposed lens would give a more traditional look.

Yes I agree and it limits the use of "off centre" compositions. Many think that you have to have f1.2 lenses for differential focus / depth of field effects. Some of my most successful reportage wedding images used the long end of a 24-70mm f2.8 L. Here the rendering and graduation from in focus to out of focus is gradual, gentle and beliveble.

 

[alan53]

Image hight seems very very likely to be an APS-C Lens, what makes a lot of sense since there are 56mm Lenses from Fuji, SIGMA and Viltrox for this Sensor-Type. It\'s a Medium Tele-Portrait Lens then and will be a very welcome addition to RF-S. Also F1.2 is far easier to achieve with the smaller Image Circle.

In these patents/applications Image height is half the image circle (i.e. ½ sensor diagonal). This design is therefore for FF lens.

 

[Dragon]

Sorry I didn't see your reply before I did. Exactly correct - and the stretching on UWA's is a personal beef of mine. I'm not sure I ever labelled those as APS-C though. I usually just subject everyone to my personal views that those lenses shouldn't be made

You should try the RF 16mm and 28mm STM lenses. The 16 is amazing for the size and the money and the 28 is hard to beat at any size or price. Perfect geometry in a lens is always a trade-off for other things (like resolution) no matter whether the correction is done optically or electronically, but note that electronic correction only affects resolution, whereas optical correction interacts with a number of other parameters. In the case of the 28 STM, the resolution is remarkable all the way to the corners even after correction, so a pretty good trade-off. Note that if you are going to expand the corners to correct distortion, there is no need to make the image height any larger than necessary. The bottom line is that optical correction may be the best choice on a 10 MP camera, but electronic correction works very well with a 45 MP camera. It is all about where you have the wiggle room the get the best final result.

 

[EricN]

You should try the RF 16mm and 28mm STM lenses. The 16 is amazing for the size and the money and the 28 is hard to beat at any size or price. Perfect geometry in a lens is always a trade-off for other things (like resolution) no matter whether the correction is done optically or electronically, but note that electronic correction only affects resolution, whereas optical correction interacts with a number of other parameters. In the case of the 28 STM, the resolution is remarkable all the way to the corners even after correction, so a pretty good trade-off. Note that if you are going to expand the corners to correct distortion, there is no need to make the image height any larger than necessary. The bottom line is that optical correction may be the best choice on a 10 MP camera, but electronic correction works very well with a 45 MP camera. It is all about where you have the wiggle room the get the best final result.

RF 16mm f/2.8 STM is impressive considering the image quality is comparable to EF14 f/2.8L ii
RF 43 mm 68.5 mm 40.6 mm 165 g $299
EF no filter 80 mm 94 mm 645 g $2,099 (at B&H)
I admit it is reasonable to say it's an unfair comparison because almost 15 years has past between the designs, but I think it shows what is possible

 

[DhlcadR6]

If anyone is using R5, I always think having the silvering primes and use crop (18MP) to act as a pseudo-zoom is more viable+compact+economical than having dedicated f2.8 zoom. When E/Z mount users look down on RF users because the lack of 'cheap' f2.8 zooms, the 1.6crop plus my feet is the best zoom mechanism