July 28, 2016, 04:41:36 AM

Author Topic: Question RE EF Lenses on EOS M and other APSC Cameras  (Read 2695 times)

justmy2cents

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Re: Question RE EF Lenses on EOS M and other APSC Cameras
« Reply #15 on: July 24, 2016, 04:44:21 AM »
Thanks. What I gathered from the article (by Tony Northrup), and I hope I didn't misrepresent his point, was that a full frame lens on a crop body wouldn't deliver the same amount of light to the sensor meaning that the seeming advantage of the lens wouldn't be so great on a crop body.

So by way of example, if I were using the EF 35mm f/2.0 on the EOS M would it be less bright at a given aperture than the native EFM 22mm f/2.0?
Thanks!

A APS-C sensor has less than half the size of a FF sensor, so you'd have to use a larger aperture because the pixels are smaller. Or you could crank up ISO, but that would increase noise.

I think the baseline of what TN is saying is: if you spent a lot of money on  FF lenses, you better get a FF body as well to make full use of them. And if you don't plan on going FF, buy crop lenses - if there are any good. 

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Re: Question RE EF Lenses on EOS M and other APSC Cameras
« Reply #15 on: July 24, 2016, 04:44:21 AM »

Sporgon

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Re: Question RE EF Lenses on EOS M and other APSC Cameras
« Reply #16 on: July 24, 2016, 05:08:00 AM »
And if you don't plan on going FF, buy crop lenses - if there are any good.

I think he is wrong, or at least out of date. The crop sensors are now so good you can actually benefit from FF EF lenses as I outlined in my post on the previous page.

mvrbnsn

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Re: Question RE EF Lenses on EOS M--THANKS TO ALL!
« Reply #17 on: July 24, 2016, 10:14:50 AM »
Wow! A big thanks to each and every one of you for your thoughtful and informative responses.
I really appreciate you taking the time to enlighten me with your knowledge and experience.

This is a great forum. Much appreciated.

Rocky

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Re: Question RE EF Lenses on EOS M and other APSC Cameras
« Reply #18 on: July 24, 2016, 01:38:43 PM »
There is another catch on using FF lens on the APSC. The APSC sensor has a multiplication factor of 1.61 linear or 2.59 area. In order to fully utilize the resolution power of the APSC sensor, the FF lens must  have 1.61 more resolution power than what is needed for the FF sensor.  M3 has a resolution of 24.2 MP.   It needs a FF lens with 62.79 MP resolution to  fully utilize the resolution power of the M3. How many FF lens can make that claim?? It is unfortunate that Canon does not make a 35mm f2.0  IS EF-M lens.

privatebydesign

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Re: Question RE EF Lenses on EOS M and other APSC Cameras
« Reply #19 on: July 24, 2016, 02:35:09 PM »
There is another catch on using FF lens on the APSC. The APSC sensor has a multiplication factor of 1.61 linear or 2.59 area. In order to fully utilize the resolution power of the APSC sensor, the FF lens must  have 1.61 more resolution power than what is needed for the FF sensor.  M3 has a resolution of 24.2 MP.   It needs a FF lens with 62.79 MP resolution to  fully utilize the resolution power of the M3. How many FF lens can make that claim?? It is unfortunate that Canon does not make a 35mm f2.0  IS EF-M lens.

You need to learn how system resolution works before making patently inaccurate comments like that.

Here is a start: http://www.canonrumors.com/forum/index.php?topic=26938.msg595091#msg595091
Too often we lose sight of the fact that photography is about capturing light, if we have the ability to take control of that light then we grow exponentially as photographers. More often than not the image is not about lens speed, sensor size, MP's or AF, it is about the light.

Rocky

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Re: Question RE EF Lenses on EOS M and other APSC Cameras
« Reply #20 on: July 24, 2016, 03:37:18 PM »
There is another catch on using FF lens on the APSC. The APSC sensor has a multiplication factor of 1.61 linear or 2.59 area. In order to fully utilize the resolution power of the APSC sensor, the FF lens must  have 1.61 more resolution power than what is needed for the FF sensor.  M3 has a resolution of 24.2 MP.   It needs a FF lens with 62.79 MP resolution to  fully utilize the resolution power of the M3. How many FF lens can make that claim?? It is unfortunate that Canon does not make a 35mm f2.0  IS EF-M lens.

You need to learn how system resolution works before making patently inaccurate comments like that.

Here is a start: http://www.canonrumors.com/forum/index.php?topic=26938.msg595091#msg595091
\
Thanks for pointing it out. I am fully aware of that. As per your quote says. When both sensor and lens resolution are matched. the end resolution is only 71%. If the lens resolution is only 66% of the sensor. The end resolution becomes only 55% of the sensor. That is 21 % reduction from the potential resolution. This is not fully utilize the resolution of the sensor. We spend money to buy expensive equipment,  we want to get the most out of it.

neuroanatomist

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Re: Question RE EF Lenses on EOS M and other APSC Cameras
« Reply #21 on: July 24, 2016, 04:29:11 PM »
There is another catch on using FF lens on the APSC. The APSC sensor has a multiplication factor of 1.61 linear or 2.59 area. In order to fully utilize the resolution power of the APSC sensor, the FF lens must  have 1.61 more resolution power than what is needed for the FF sensor.  M3 has a resolution of 24.2 MP.   It needs a FF lens with 62.79 MP resolution to  fully utilize the resolution power of the M3. How many FF lens can make that claim?? It is unfortunate that Canon does not make a 35mm f2.0  IS EF-M lens.

You need to learn how system resolution works before making patently inaccurate comments like that.

Here is a start: http://www.canonrumors.com/forum/index.php?topic=26938.msg595091#msg595091
\
Thanks for pointing it out. I am fully aware of that. As per your quote says. When both sensor and lens resolution are matched. the end resolution is only 71%. If the lens resolution is only 66% of the sensor. The end resolution becomes only 55% of the sensor. That is 21 % reduction from the potential resolution. This is not fully utilize the resolution of the sensor. We spend money to buy expensive equipment,  we want to get the most out of it.

How is it that, as you imply, your argument applies to FF lenses used on APS-C cameras, but not APS-C lenses used on APS-C cameras?  Or do you believe that APS-C lenses intrinsically deliver higher resolution?  Sorry, but I can't really see any relevance to your point in this discussion of using FF lenses on APS-C cameras.  Yes, smaller pixels benefit more from higher resolution lenses, but the pixels of the M3 aren't all that much smaller than those on the 5DsR (same density as a 20 MP APS-C sensor). 

If anything, since lens resolving power is generally highest in the center and drops toward the periphery, the benefit from using only the center of the FF image circle is quite significant – a glance at the 35/2 IS MTF chart shows resolution remains quite high through area of the APS-C sensor.
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Re: Question RE EF Lenses on EOS M and other APSC Cameras
« Reply #21 on: July 24, 2016, 04:29:11 PM »

dougkerr

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Re: Question RE EF Lenses on EOS M and other APSC Cameras
« Reply #22 on: July 24, 2016, 09:36:42 PM »
The rationale was that the amount of light reaching the sensor is greatly reduced on a crop body camera such that an f/2.0 lens ends up being almost an f/4.0!

The illuminance on the sensor (for a given scene luminance), which (along with the shutter speed) is the factor that determines the photometric exposure, the quantity to which the sensor responds, is determined by the f-number of the lens. Period.

Best regards,

Doug

privatebydesign

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Re: Question RE EF Lenses on EOS M and other APSC Cameras
« Reply #23 on: July 24, 2016, 10:44:57 PM »
The rationale was that the amount of light reaching the sensor is greatly reduced on a crop body camera such that an f/2.0 lens ends up being almost an f/4.0!

The illuminance on the sensor (for a given scene luminance), which (along with the shutter speed) is the factor that determines the photometric exposure, the quantity to which the sensor responds, is determined by the f-number of the lens. Period.

Best regards,

Doug

The point is the sensor receives photons as a function of area, ergo a sensor that is less than half the size receives less than half the photons. That is why FF cameras are at least one stop better in ISO noise performance for any given exposure and output size.
Too often we lose sight of the fact that photography is about capturing light, if we have the ability to take control of that light then we grow exponentially as photographers. More often than not the image is not about lens speed, sensor size, MP's or AF, it is about the light.

Fleetie

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Re: Question RE EF Lenses on EOS M and other APSC Cameras
« Reply #24 on: July 26, 2016, 08:03:33 AM »
The rationale was that the amount of light reaching the sensor is greatly reduced on a crop body camera such that an f/2.0 lens ends up being almost an f/4.0!

The illuminance on the sensor (for a given scene luminance), which (along with the shutter speed) is the factor that determines the photometric exposure, the quantity to which the sensor responds, is determined by the f-number of the lens. Period.
And the T-stop.
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jolyonralph

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Re: Question RE EF Lenses on EOS M and other APSC Cameras
« Reply #25 on: July 27, 2016, 04:04:02 AM »
You already use the 50mm f/1.8 with an adaptor, so that should tell you the article is nonsense as presumably you're happy with the results!

The 35mm f/2.0 would be a nice partner for the EOS-M - I'm considering getting one myself
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mb66energy

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Re: Question RE EF Lenses on EOS M and other APSC Cameras
« Reply #26 on: July 27, 2016, 05:27:38 AM »
There is another catch on using FF lens on the APSC. The APSC sensor has a multiplication factor of 1.61 linear or 2.59 area. In order to fully utilize the resolution power of the APSC sensor, the FF lens must  have 1.61 more resolution power than what is needed for the FF sensor.  M3 has a resolution of 24.2 MP.   It needs a FF lens with 62.79 MP resolution to  fully utilize the resolution power of the M3. How many FF lens can make that claim?? It is unfortunate that Canon does not make a 35mm f2.0  IS EF-M lens.

You need to learn how system resolution works before making patently inaccurate comments like that.

Here is a start: http://www.canonrumors.com/forum/index.php?topic=26938.msg595091#msg595091
\
Thanks for pointing it out. I am fully aware of that. As per your quote says. When both sensor and lens resolution are matched. the end resolution is only 71%. If the lens resolution is only 66% of the sensor. The end resolution becomes only 55% of the sensor. That is 21 % reduction from the potential resolution. This is not fully utilize the resolution of the sensor. We spend money to buy expensive equipment,  we want to get the most out of it.

How is it that, as you imply, your argument applies to FF lenses used on APS-C cameras, but not APS-C lenses used on APS-C cameras?  Or do you believe that APS-C lenses intrinsically deliver higher resolution?  Sorry, but I can't really see any relevance to your point in this discussion of using FF lenses on APS-C cameras.  Yes, smaller pixels benefit more from higher resolution lenses, but the pixels of the M3 aren't all that much smaller than those on the 5DsR (same density as a 20 MP APS-C sensor). 

If anything, since lens resolving power is generally highest in the center and drops toward the periphery, the benefit from using only the center of the FF image circle is quite significant – a glance at the 35/2 IS MTF chart shows resolution remains quite high through area of the APS-C sensor.

I see a better resolution of my EF-S 60 compared to the EF 100 (non-IS) in my images. I am shure that isn't intrinsical but a result of lens optimization for the use case.

A FF lens must have reasonable quality for an image circle of ~43mm while the APS-Lens only needs ~26mm image circle of reasonable IQ.

Classic FF lenses are too optimized for the center region where most subjects in standard compositions are located (e.g. the 24mm 2.8 non-IS) but I am shure that there is some co-optimization in newer lenses for both, FF and APS-C. The 35mm 2.0 is - in my opinion - a good example for a dual use lens with extraordinary resolution within the APS-C image circle and very good res. for the rest of the area.

My conclusion is that an EF-S or a newer EF lens should work optimally on APS-C sensors. Older lenses (pre APS-C era) should be checked.
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AE-1Burnham

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Re: Question RE EF Lenses on EOS M and other APSC Cameras
« Reply #27 on: July 27, 2016, 06:00:26 AM »
Wouldn't it be cool if Canon made a Speedbooster for EF to APSC sensor?! Or if Metabones made a EF to "APSC" or "EF-M" adaptor. God that would make me so happy. :-) (I imagine Canon Corporate would get quite angry at Metabones and out would come lawyers and such...) If this existed I would buy an M series camera immediately.
« Last Edit: July 27, 2016, 06:02:43 AM by AE-1Burnham »
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Re: Question RE EF Lenses on EOS M and other APSC Cameras
« Reply #27 on: July 27, 2016, 06:00:26 AM »