Patent: Canon RF 35mm f/1.2L USM

wanderer23

EOS M6 Mark II
CR Pro
Feb 8, 2020
69
75
Can't wait! have the 50L and can only afford one more prime at the moment after so many unwarranted purchases this year (haha) - so been waiting for this one over getting the 85L
 

Aaron D

Hey!
Jul 21, 2016
270
263
Kansas City
www.aarondougherty.com
Or even a f/2 28mm. A sort of melding of the old EF f/1.8 + 2.8 versions would be ideal. Compact is the main thing for my travel/street photo use.

I've had two different 35's over the years but ended up selling both for lack of use. I want to like that focal length but just don't see things that way.
 

Del Paso

M3 Singlestroke
Aug 9, 2018
1,143
1,189
Some similarity with the EF-S 32: The light travels mostly through glass! Lots of thick lenses and a large number of elements - T1.8?
I keep wondering too.
Leica's 0,95 Noctilux has only 8 lenses, Canon's 1,2/35, if I'm not mistaken, 18 !
18 lenses will certainly absorb some light...
 

Del Paso

M3 Singlestroke
Aug 9, 2018
1,143
1,189
What relevance does the T stop have for photography?
F stop is purely math, based on 2 parameters :focal length and diameter of front lens.
2 lenses with the same f stop can have a different luminosity.
T stop takes into account the real light transmission of a lens, which depends on the number and transparency of a lens' elements.
So, with less serious lens makers, an f1,4 could easily be a real 1,8 lens.
Almost all cine versions of photo lenses (Canon's) have a higher T stop, which, unlike the f stop, is used for exposure measuring.
Fact is, more elements absorb more light .
Yet, regardless of the light transmission, an f 1,2 will have the depth of field of an f 1,2, even if it were a T 1,8...
 
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privatebydesign

EOS-1D X Mark III
CR Pro
Jan 29, 2011
9,998
4,781
F stop is purely math, based on 2 parameters :focal length and diameter of front lens.
2 lenses with the same f stop can have a different luminosity.
T stop takes into account the real light transmission of a lens, which depends on the number and transparency of a lens' elements.
So, with less serious lens makers, an f1,4 could easily be a real 1,8 lens.
Almost all cine versions of photo lenses (Canon's) have a higher T stop, which, unlike the f stop, is used for exposure measuring.
Fact is, more elements absorb more light .
Yet, regardless of the light transmission, an f 1,2 will have the depth of field of an f 1,2, even if it were a T 1,8...
I know what T stops are, I am asking specifically why you think they are relevant in stills photography. It doesn’t matter if the lens loses something in transmission (they all do) what matters in stills photography is the depth of field and that is dictated by the aperture not the transmission characteristics. TTL metering rendered t-stops irrelevant for stills shooting decades ago.

The differences of fractions of a stop in transmission characteristics of lenses have absolutely zero relevance that I can see in stills photography.

P.S. Aperture, or f stop, isn’t based on “the diameter of the front lens”, it is the actual focal length divided by the apparent diameter of the entrance pupil.
 
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Del Paso

M3 Singlestroke
Aug 9, 2018
1,143
1,189
I know what T stops are, I am asking specifically why you think they are relevant in stills photography. It doesn’t matter if the lens loses something in transmission (they all do) what matters in stills photography is the depth of field and that is dictated by the aperture not the transmission characteristics. TTL metering rendered t-stops irrelevant for stills shooting decades ago.

The differences of fractions of a stop in transmission characteristics of lenses have absolutely zero relevance that I can see in stills photography.

P.S. Aperture, or f stop, isn’t based on “the diameter of the front lens”, it is the actual focal length divided by the apparent diameter of the entrance pupil.
What I actually meant is: are so many lenses really needed, since Leica, for instance, succeed in making brilliant luminous wide angles and other lenses, using a maximum of 10 elements.
Fact remains, that any difference between T and F stops results in a reduced low-light ability .Whether this matters, is up to the user.
But there are some specific situations where a half or a third of a diaphragm can actually make a difference.
PS: thanks for the correction ("diameter of the front lens")
PPS: I was aware of your knowing what a T stop is, but some forum members reading this post might not. No "offense" intended !:)
 
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privatebydesign

EOS-1D X Mark III
CR Pro
Jan 29, 2011
9,998
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What I actually meant is: are so many lenses really needed, since Leica, for instance, succeed in making brilliant luminous wide angles and other lenses, using a maximum of 10 elements.
Fact remains, that any difference between T and F stops results in a reduced low-light ability .Whether this matters, is up to the user.
But there are some specific situations where a half or a third of a diaphragm can actually make a difference.
PS: thanks for the correction ("diameter of the front lens")
PPS: I was aware of your knowing what a T stop is, but some forum members reading this post might not. No "offense" intended !:)
If a lens is f2.0 and has good transmission it will be around T1.9, a ‘bad’ lens will be around T1.7, my point is that difference between 1.9 and 1.7 is not significant enough to be of any concern to anybody in a photography context.

Just bringing t stops into the conversation will confuse people who don’t know what they are and cause them to worry about something that firstly, won’t make any difference to their photography and secondly, they can’t do anything about anyway.

Absolutely no offense taken by me or implied by me either. :)
 
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privatebydesign

EOS-1D X Mark III
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Jan 29, 2011
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If I buy an f/1.4 lens with T 2.0 I will definitely get the bokeh but i have to increase ISO or exp time by one stop - so you do not get the benefits from higher stops.
But that isn’t very realistic, as I already said all lenses lose something and the differences between a good lens and a ‘bad’ lens for transmission are not that much.

On the other hand something like vignetting has a far greater real world impact for photographers, especially on fast glass. Sony might be winning a lot of hearts and minds for their new small fast glass but who is also pointing out that to do that without severe vignetting they have to be cooking the RAW files and applying exposure corrections?

Now that is a real world compromise that photographers should be talking about.
 

mb66energy

EOS 5D Mark IV
Dec 18, 2011
1,504
373
Germany
www.MichaelBockhorst.de
But that isn’t very realistic, as I already said all lenses lose something and the differences between a good lens and a ‘bad’ lens for transmission are not that much.

On the other hand something like vignetting has a far greater real world impact for photographers, especially on fast glass. Sony might be winning a lot of hearts and minds for their new small fast glass but who is also pointing out that to do that without severe vignetting they have to be cooking the RAW files and applying exposure corrections?

Now that is a real world compromise that photographers should be talking about.

Yes, it is a world of compromises.

And it would be great to see more data - compared to the RF 1.8 35mm lens F 1.2 scheme has nearly twice the glass-air surfaces and 2 ... 3x the path through glass so I expect a clearly measurable/relevant difference in transmission.

I agree that each photographer has to choose the "balance of compromises" according to the application!
 

privatebydesign

EOS-1D X Mark III
CR Pro
Jan 29, 2011
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Yes, it is a world of compromises.

And it would be great to see more data - compared to the RF 1.8 35mm lens F 1.2 scheme has nearly twice the glass-air surfaces and 2 ... 3x the path through glass so I expect a clearly measurable/relevant difference in transmission.

I agree that each photographer has to choose the "balance of compromises" according to the application!
But the problem becomes one of getting what we ask for without realizing the costs.

I love that Canon still essentially give us access to relatively uncooked RAW files, I hate that Sony don’t and that they use up a portion of their editability by covering up the lensEs shortcomings. But you know what will happen next if we keep drinking that cool aid? Canon will be forced to doctor their RAW files even more to ‘keep up’, which isn’t keeping up at all it is dumbing down.

In the scheme of things T stops are an irrelevant distraction from the much bigger issue of cooking RAW files.
 

mb66energy

EOS 5D Mark IV
Dec 18, 2011
1,504
373
Germany
www.MichaelBockhorst.de
But the problem becomes one of getting what we ask for without realizing the costs.

I love that Canon still essentially give us access to relatively uncooked RAW files, I hate that Sony don’t and that they use up a portion of their editability by covering up the lensEs shortcomings. But you know what will happen next if we keep drinking that cool aid? Canon will be forced to doctor their RAW files even more to ‘keep up’, which isn’t keeping up at all it is dumbing down.

In the scheme of things T stops are an irrelevant distraction from the much bigger issue of cooking RAW files.
Cooking RAWs is a different thing and has nothing to do with T-stops IMO.

But as physicist I agree 100% with your opinion about cooking RAWs: It is a no go. I want the real original really raw data - processing should be a separated step done independently and without any loss of the original data. That was always the reason to use RAW - exploit more and more information with increased knowledge and processing power about/of computers.
 
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