The RF 24-240mm f/4-6.3 IS is coming soon

ozturert

EOS T7i
Jan 16, 2019
86
68
No problem using EF-S on RF with the adapter (other than the crop) I have not seen any signs of vignetting.
Yes EF-S lenses can be used with crop. The cameras automatically switches to APS-C mode with EF-S lenses. This us actually good in 4K video because RF cameras apply 1.8x crop in 4K video. With EF-S lenses I can compensate for this crop.
 

SecureGSM

EOS 6D MK II
Feb 26, 2017
1,066
152
No problem using EF-S on RF with the adapter (other than the crop) I have not seen any signs of vignetting.
yes, as it was explain to me by the OP (above), the \canon EF - RF adaptor command the R body that an EF-S lens is attached and body set itself into a "crop mode". essentially your image is the x1.6 crop of a centre area of your FF sensor, hence no vignetting.
I wonder if this is exactly what Canon called "an elegant solution". definitely a good one.
Shooting video with Sigma EF 18-35 / 1.8 on an R platform seems to be an excellent option. the lens is nearly parfocal and offers a very nice zoom range. hm..
 
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LSXPhotog

EOS RP
Apr 2, 2015
351
177
www.diossiphotography.com
Just my honest opinion, Canon should have waited to release the RP until this lens was ready for the market. It seems that everyone has been bitching and complaining about the prices of the lenses for the RF mount versus the price the RP. This lens should have been offered as the exclusive kit lens option with that camera and not the 24-105L and the EF 24-105 non L that nobody has ever purchased because it's the same price new is the L series is as a kit.
 
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AlanF

Everyone sits in the prison of his own ideas. A E
Aug 16, 2012
5,258
2,285
I use my EF lenses with adapter, but native RF lenses are able to have a larger rear element which decreases the angle at which light rays strike the sensor. That is better, less light fall off at the edges and less distortion.
It would seem to me intuitively that the wider the rear element and the closer it is to the sensor, the worse the vignetting because the sharper the angle of a ray from the outer part of the lens hitting the opposite edge of the sensor (say a ray from the extreme left hitting the sensor on the extreme right). Has Canon written somewhere that the RF lenses should be better at vignetting?
The two RF lenses tested by Optical limits on the R do have worse vignetting than their EF equivalents on a DSLR:
RF 1.2 f/1.2 Vignetting 3.24ev
EF 1.2 f/1.2 Vignetting 2.74ev

RF 24-105mm, f/4 Vignetting 24mm 2.6ev; 105mm 2.1ev
EF 24-105mm II, f/4 Vignetting 24mm 1.9ev; 105mm 1.45ev
 

SecureGSM

EOS 6D MK II
Feb 26, 2017
1,066
152
It would seem to me intuitively that the wider the rear element and the closer it is to the sensor, the worse the vignetting because the sharper the angle of a ray from the outer part of the lens hitting the opposite edge of the sensor (say a ray from the extreme left hitting the sensor on the extreme right). Has Canon written somewhere that the RF lenses should be better at vignetting?
The two RF lenses tested by Optical limits on the R do have worse vignetting than their EF equivalents on a DSLR:
RF 1.2 f/1.2 Vignetting 3.24ev
EF 1.2 f/1.2 Vignetting 2.74ev

RF 24-105mm, f/4 Vignetting 24mm 2.6ev; 105mm 2.1ev
EF 24-105mm II, f/4 Vignetting 24mm 1.9ev; 105mm 1.45ev
Yup, good catch. Expected. The shorter the flange distance the stronger the light falloff centre to extreme corners. I do not recall any vignetting related comments by Canon to date.
 

koenkooi

EOS RP
Feb 25, 2015
362
205
Yup, good catch. Expected. The shorter the flange distance the stronger the light falloff centre to extreme corners. I do not recall any vignetting related comments by Canon to date.
Didn't Canon say they tweaked the micro lenses on the sensor to help with vignetting?
 

SecureGSM

EOS 6D MK II
Feb 26, 2017
1,066
152
Well they can tweak that all they want but variability of distances between lense to Centre of the sensor and lense to corners suggest a stronger light falloff for RF system.
 
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mb66energy

EOS 6D MK II
Dec 18, 2011
1,234
158
Germany
www.MichaelBockhorst.de
Any leaks about the size and weight of the 24-240 lens? If it's lightweight, I will seriously reconsider delving back to the world of FF.
From the photos I would guess ~85mm diameter and 135mm length (smallest setting). Weight is a very rough guess: I think it will be in the region of 900 grams. This one with a hypothetical RF 1.8 50 or 85 Macro (in the RF 35mm style) would make a serious, compact and flexible "photographic solution" for those who want go light and do not want to lug around a lot of weight: 24-240 for brighter days, 50/85 1.8 for darker environments or more close focus or more DOF-reduction.
 

mb66energy

EOS 6D MK II
Dec 18, 2011
1,234
158
Germany
www.MichaelBockhorst.de
Yup, good catch. Expected. The shorter the flange distance the stronger the light falloff centre to extreme corners. I do not recall any vignetting related comments by Canon to date.
This is TRUE if you make a pan cake lens where you exploit the short flange distance for compactness: The lens group is placed close to the sensor but you have flat angles (measured against sensor surface) which show a stronger reflection (less light onto the sensor photodiodes).
This is NOT true if you have a lens element placed close to the sensor that bends the light from flat angles (measured against sensor surface) into a "more perpendicular" direction.

Basically a short flange distance creates more "freedom of lens design" - the compromise between aberrations and size/weight etc.
 

ozturert

EOS T7i
Jan 16, 2019
86
68
No. Someone needs to learn what the word infinite means.
Yes, infinitely was exaggeration. A native lens will be a lot better for new Canon users and for photographers who don't want to deal with an additional interface (both physical and electronic).
 

BurningPlatform

EOS T7i
Mar 4, 2014
78
20
I had to read your comment literary three time to even understand your point.
You are grossly incorrect. Full frame or not, exposure Values will be identical for a FF or crop sensor camera body.
Angle of view will be different, high iso performance will be different but that is due to crop sensor inferior high iso abilities, not lens.
F4 in full frame is a full stop slower than F2.8. And even shooting withF2.8 zooms, I frequently reaching for a fast prime to keep iso levels within my comfort zone on 5D IV (6400)
Well, actually, the total light (number of photons) captured by a full frame sensor with the same aperture is 1,6² times more than the total light captured on the final image of a Canon APS-C sensor. You have to (basically) multiply the exposure with the area of the sensor to get the total light. That is the ground reason why the same generation of sensors with the same number of pixels on APS-C have worse high ISO performance (at image and pixel level) than the FF sensors.There are less photons to form the image both for each pixel and the total image on APS-C in this case.

Thus, the total amount of light hitting the FF sensor from an f4.0 lens is the same as the total light of an f2.5 (4/1.6) lens on Canon APS-C, as the aperture is calculated linearly against a single image dimension,( not f1.56, as previously claimed).

Of course, if you crop the FF image to APS-C in post, you get a more or less identical image with he same lens, but that is not the point here.
 
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SecureGSM

EOS 6D MK II
Feb 26, 2017
1,066
152
Well, actually, the total light (number of photons) captured by a full frame sensor with the same aperture is 1,6² times more than the total light captured on the final image of a Canon APS-C sensor. You have to (basically) multiply the exposure with the area of the sensor to get the total light. That is the ground reason why the same generation of sensors with the same number of pixels on APS-C have worse high ISO performance (at image and pixel level) than the FF sensors.There are less photons to form the image both for each pixel and the total image on APS-C in this case.

Thus, the total amount of light hitting the FF sensor from an f4.0 lens is the same as the total light of an f2.5 (4/1.6) lens on Canon APS-C, as the aperture is calculated linearly against a single image dimension,( not f1.56, as previously claimed).

Of course, if you crop the FF image to APS-C in post, you get a more or less identical image with he same lens, but that is not the point here.
Break out a light meter and take exposure of the scene for a FF camera with a FF lens attached and then for a aps-c camera with an aps-c lens attached. Are they any different?
So....
 
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Don Haines

Beware of cats with laser eyes!
Jun 4, 2012
8,025
1,487
Canada
Well, actually, the total light (number of photons) captured by a full frame sensor with the same aperture is 1,6² times more than the total light captured on the final image of a Canon APS-C sensor. You have to (basically) multiply the exposure with the area of the sensor to get the total light. That is the ground reason why the same generation of sensors with the same number of pixels on APS-C have worse high ISO performance (at image and pixel level) than the FF sensors.There are less photons to form the image both for each pixel and the total image on APS-C in this case.

Thus, the total amount of light hitting the FF sensor from an f4.0 lens is the same as the total light of an f2.5 (4/1.6) lens on Canon APS-C, as the aperture is calculated linearly against a single image dimension,( not f1.56, as previously claimed).

Of course, if you crop the FF image to APS-C in post, you get a more or less identical image with he same lens, but that is not the point here.
The density of light with an F4.0 lens on a FF sensor is the same as the density of light with a crop F4.0 lens on a crop lens.
 

Kit.

EOS 6D MK II
Apr 25, 2011
1,103
522
Break out a light meter and take exposure of the scene for a FF camera with a FF lens attached and then for a aps-c camera with an aps-c lens attached. Are they any different?
So....
Sensor's illuminance for the same relative aperture is the same, but the luminous flux through the FF sensor is 1.6² times higher.

With the same absolute aperture (and angle of view), the luminous flux through the both sensors would be the same, but the APS sensor would need to have higher capacitance per unit area to keep the photoelectrons from overflowing it.
 

SecureGSM

EOS 6D MK II
Feb 26, 2017
1,066
152
Sensor's illuminance for the same relative aperture is the same, but the luminous flux through the FF sensor is 1.6² times higher.

With the same absolute aperture (and angle of view), the luminous flux through the both sensors would be the same, but the APS sensor would need to have higher capacitance per unit area to keep the photoelectrons from overflowing it.
Now, read what was the original statement I had a reply to.then read what you just wrote. Find a relevance. It had nothing to do with sensor. Hint. It was about a lens.
And how aps-c lens light gathering capacity , f-stop is different from a full frame lens f-stop.

f/4 in full frame is not that slow. It would gather the same amount of light as a f/1.56 EF-S
 
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Kit.

EOS 6D MK II
Apr 25, 2011
1,103
522
Now, read what was the original statement I had a reply to.then read what you just wrote. Find a relevance. It had nothing to do with sensor. Hint. It was about a lens.
And how aps-c lens light gathering capacity , f-stop is different from a full frame lens f-stop.
An APS-C lens normally has a smaller image circle than a FF lens. So, whatever I said about illuminance and liuminous flux for sensors, is also relevant for lenses.
 

neuroanatomist

I post too Much on Here!!
Jul 21, 2010
24,379
1,726
An APS-C lens normally has a smaller image circle than a FF lens. So, whatever I said about illuminance and liuminous flux for sensors, is also relevant for lenses.
True. Plus the fact that discussing the light gathered by a lens in the absence of a sensor to capture it is rather irrelevant.
 
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Bob Howland

EOS 7D MK II
Mar 25, 2012
428
25
It would seem to me intuitively that the wider the rear element and the closer it is to the sensor, the worse the vignetting because the sharper the angle of a ray from the outer part of the lens hitting the opposite edge of the sensor (say a ray from the extreme left hitting the sensor on the extreme right). Has Canon written somewhere that the RF lenses should be better at vignetting?
The two RF lenses tested by Optical limits on the R do have worse vignetting than their EF equivalents on a DSLR:
RF 1.2 f/1.2 Vignetting 3.24ev
EF 1.2 f/1.2 Vignetting 2.74ev

RF 24-105mm, f/4 Vignetting 24mm 2.6ev; 105mm 2.1ev
EF 24-105mm II, f/4 Vignetting 24mm 1.9ev; 105mm 1.45ev
I'll agree with you regarding the distance from rear element to sensor but not regarding diameter of rear element. The rear element is not going to be designed to direct a light ray from one side of the rear element to the opposite side of the sensor. Rather it will be designed to direct the ray outward onto the same side of the sensor. A larger diameter rear element will reduce the amount of light bending occurring in the rear element.

To change the subject and to repeat myself, I want to know if there is a difference in rear element diameter in EF and RF lenses. Some people seem to be assuming that the RF rear elements are larger than EF rear elements. This is far from obvious to me and I would like people to actually measure the diameter of RF lens rear elements, especially the 50 f/1.2 and 28-70 f/2. The three EF lens rear elements I measured all were 37-38mm in diameter.