Here are the full Canon EOS R specifications

Mar 2, 2012
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I am correct.

CanonFanBoy is correct. Although a f/2 lens is an f/2 lens, a M43 sensor is smaller than a FF sensor and hence M43 f/2 lens is slower than a FF f/2 lens. You have to apply the multiplication factor to get the 35mm equivalent.

A slower lens is a lens that lets in less light! A M43 lens with the f-stop as a FF lets in less light than the FF lens.


A 500mm^2 hole is a 500mm^2 hole no matter what you strap it to.

Disregarding unquantifiable losses (difference between f and t stops), if you sample a scene with equivalent framing, aperture, and exposure time using a m43 and full frame, the same amount of light will pass through. But if you view the resulting images at the same size, the one you magnify less will look better.
 
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Agreed, but I'd rather all lenses (that need it) were brought up to speed with IS. In my case, my normal zoom, long zoom and 35 fixed are all IS and only my TSE lenses are not. So, I'd be paying for IBIS and living with the added complexity for NO good reason.
Yes, in your perfect world.
 
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same argument could be applied to power steering, electric windows, and a whole host of features which differentiate your car from a 1960s family saloon ...
I've said it elsewhere, so apologies for repeating myself…. I don't have any lenses that don't already have IS built-in—why pay for and have to drag around the extra complexity? IBIS is absolutely useless to everybody who owns IS lenses. Yeah there are some lenses that don't have IS yet—fix THEM!
 
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Jul 21, 2010
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I am correct.

CanonFanBoy is correct. Although a f/2 lens is an f/2 lens, a M43 sensor is smaller than a FF sensor and hence M43 f/2 lens is slower than a FF f/2 lens. You have to apply the multiplication factor to get the 35mm equivalent.

A slower lens is a lens that lets in less light! A M43 lens with the f-stop as a FF lets in less light than the FF lens.
You can repeat yourself as often as you like, but it won’t make you correct. However, it seems there’s no point me in trying to explain it to you again.
 
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Talys

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I am correct.

CanonFanBoy is correct. Although a f/2 lens is an f/2 lens, a M43 sensor is smaller than a FF sensor and hence M43 f/2 lens is slower than a FF f/2 lens. You have to apply the multiplication factor to get the 35mm equivalent.

A slower lens is a lens that lets in less light! A M43 lens with the f-stop as a FF lets in less light than the FF lens.

The f-stop is simply the focal length divided by the aperture diameter. For example, 100mm focal length divided by pupil dimeter of 50mm = f/2. Divided by a pupil diameter of 25mm, it would be f/4. This is literally the mathematical definition of the f-number (N = f/D).

The brightness of the projected scene has absolutely nothing to do with the size of the sensor. If you use a sensor smaller than the projected image circle, you'll just cut off (crop) the image. However, it would be accurate to say that using a smaller sensor behind the same optics will capture fewer photons (of course).

Instead of comparing sensors of the same aspect ratio, imagine if you took a FF sensor, and cut it in vertically in half down the middle. The left half sensor would now capture exactly half the light (number of photons) as the whole sensor. But the image and exposure settings on the left half sensor would be exactly the same as that of the whole sensor, and the image on the left half sensor would be the same as the image on the whole sensor, if you just cropped off the left half.

From a practical perspective, if you're using a Sekonic light meter to measure your exposure settings given your strobe setup... you don't dial in whether you are using a MFT or FF sensor. Given the amount of light you're throwing on your subject, the exposure settings will be the same regardless of MFT/APSC/FF.
 
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unfocused

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Jul 20, 2010
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You can repeat yourself as often as you like, but it won’t make you correct. However, it seems there’s no point me in trying to explain it to you again.

Neuro, don't you know that handheld light meters have a special setting for the size of the film/sensor? Oh... wait...
 
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Jul 21, 2010
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Neuro, don't you know that handheld light meters have a special setting for the size of the film/sensor? Oh... wait...
I think his problem was that he was trying to examples it in terms of sensor size. Now, if he’d said that a Panasonic f/2 lens is slower than a Canon f/2 lens is slower than a Hasselblad f/2 lens is slower than a Hubble f/2 lens, it might have made for better comedy.
 
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Ozarker

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Ha you get offensive I see..! i dont care for other brands except for the one I have invested so much money all these years... I was expecting from Canon much more this time after all this waiting..!

Not offended, annoyed. Have fun with your Sony. Somehow, I don't believe you will switch. Sony paying Canon? Must be a joke.
 
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A 500mm^2 hole is a 500mm^2 hole no matter what you strap it to.

Disregarding unquantifiable losses (difference between f and t stops), if you sample a scene with equivalent framing, aperture, and exposure time using a m43 and full frame, the same amount of light will pass through. But if you view the resulting images at the same size, the one you magnify less will look better.

Yes.

But if the same amount of light is channeled/concentrated onto a smaller sensor, wouldn't it actually mean that an equivalent f/stop lens for M43 be faster than its FF counterpart. To elaborate;

Say we have 2 85mm f/2 lenses, one M43 and one FF. The focal length is the same, so the entrance pupil is the same. the light gathered however is projected to different sized sensors. Assuming M43 is half the area of FF, then the same amount of light is concentrated differently, with the M43 having more intense light? Would that not mean that the 85 f/2 M43 lens is faster?
 
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I've said it elsewhere, so apologies for repeating myself…. I don't have any lenses that don't already have IS built-in—why pay for and have to drag around the extra complexity? IBIS is absolutely useless to everybody who owns IS lenses. Yeah there are some lenses that don't have IS yet—fix THEM!

As someone who owns IS lenses and cameras with IBIS, the combination of the two is remarkable. If you don't shoot much in low light, you won't need it, but there's many who benefit from being able to run a slower shutter speed when in running hand held. It's also almost downright magical for those who shoot video and has forced my DJI gimbal to gather dust.
 
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In most cases if your power windows or heated seats quit working you can still drive your car. You can also find a repair shop right down the road. If your IBIS quits working well your camera is not going to produce. That being said I guess the same could be said for IS Lens stabilization also.
and engine management systems too !
 
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Aug 21, 2018
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As someone who owns IS lenses and cameras with IBIS, the combination of the two is remarkable. If you don't shoot much in low light, you won't need it, but there's many who benefit from being able to run a slower shutter speed when in running hand held. It's also almost downright magical for those who shoot video and has forced my DJI gimbal to gather dust.
Could not agree more! IBIS should be a standard feature in 2018/19. Especially in high end/FF cameras.
 
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I've said it elsewhere, so apologies for repeating myself…. I don't have any lenses that don't already have IS built-in—why pay for and have to drag around the extra complexity? IBIS is absolutely useless to everybody who owns IS lenses. Yeah there are some lenses that don't have IS yet—fix THEM!

IBIS can work in conjunction with the lens IS and make it even better still ....
 
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Sharlin

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This may be neither here nor there, but there is more to it than light volume. There is also a geometric difference (incident angle of the light rays being sampled), so I’m not sure it’s fair to assume something like “camera x is AF sensitive at -6EV using a f/1.2 lens, therefore it will be AF sensitive at -5EV using an f/1.8 lens.”

Yes, this. A discrete PDAF system is limited by the secondary mirror effectively functioning as an extra aperture stop. Moreover, the baseline, or separation between the two sensor strips making up an AF "point", constrains the phase difference that can be recorded. This is why "normal" AF points in Canon bodies have a fairly constant sensitivity up to f/4 or f/5.6, and only the long-baseline diagonal points in the center are extra sensitive at f/2.8.

But with DPAF it's a different story. What Canon is saying is that the sensitivity of this DPAF implementation keeps improving with faster lenses all the way down to f/1.2. This is pretty cool.
 
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Jul 21, 2010
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Yes.

But if the same amount of light is channeled/concentrated onto a smaller sensor, wouldn't it actually mean that an equivalent f/stop lens for M43 be faster than its FF counterpart. To elaborate;

Say we have 2 85mm f/2 lenses, one M43 and one FF. The focal length is the same, so the entrance pupil is the same. the light gathered however is projected to different sized sensors. Assuming M43 is half the area of FF, then the same amount of light is concentrated differently, with the M43 having more intense light? Would that not mean that the 85 f/2 M43 lens is faster?
What makes you think the ‘light is channeled/concentrated onto a smaller sensor’?? Actually, where you got that idea doesn’t really matter, that’s not what’s happening. Crop factor is called that for a reason. Crop. Think about it.

The situation you’re describing can happen, but only when using a lens with a larger image circle than needed for the sensor, and only with additional optics. Imagine a 0.7x TC. Or just Google speedbooster.
 
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