[Brightcolours]

....
Besides that, the Olympus is a sharp lens of course, that is apparent. In FF terms, a sharp, slow 24-200mm f8 lens. A slow lens that weighs 239 grams less than the faster Canon 24-240mm f4-6.3 lens. A slow lens that is weather sealed, and $200 more expensive.

The last 3 lines of the above quote I was referring to.

The Canon is not a faster lens. It just has less DoF on a FF sensor that the Oly on an MFT sensor.

Kind regards, Wim

So, lets see. Saying that the Olympus "is  sharp lens of course, that is apparent" is dissing it?
And saying that in Full Frame terms, it is a sharp, slow 24-200mm f8 lens is dissing it? Or factually stating that it weighs less is dissing? Or more expensive?

In FF terms, the Canon is faster. In FF terms. Try it yourself. To use it with an FF sensor, and use it like a 24-200mm lens, you need to put a 2x TC on it. Guess what the max. f-value will be.

The odd thing is that you fall over the f8 part but not the 24-200mm part. Strange.

And are you saying that 20 years ago rap was not yet there, dude bro? "Diss" is certainly rapper lingo, it originates from Jamaican and AAVE, and has been popularised by rap culture. A bit odd that you think in terms of "disrespecting a lens", I have to say.

The word diss indeed derives from disrespect or disparage, and was originally spelt dis. First record in a dictionary dates from 1905. Those were very early rappers I guess, not-a-bro.

I am harping on about you saying it is an F/8 lens. I don’t care about the FL, as long as it is equivalent, basically in order to determine magnification and/or FoV for a specific lens/sensor combination. However, F/4 is F/4 is F/4, as only the physical aperture determines the effect of optical diffraction. An F/2 lens on a mobile phone with a 7.2 mm sensor diameter is not called an F/72 lens either, and neither does it behave like an optic at F/72 with regard to diffraction effect (at F/72 the resolution would be in the order of a few line pairs per mm).

Regards, Wim

And what does that first record in a dictionary say about its origins? AAVE? And has AAVE been widely used across the whole english speaking population of the world? No.
Meriam Webster notes the 1st known use of "diss" in this meaning to be from 1987. So what did popularise the use of "diss"? Yep. Rap culture. And you still think it is normal to say someone can "disrespect" a lens, dude/bro? 

You appear to have a blind spot. I say that in FF terms, this MFT lens is like a 24-200mm f8 lens. Or: this lens is equivalent to a 24-200mm f8 lens.

Funny thing: you don't care about FL as long it is equivalent. Yet you do (in the wrong way) care about f-value, even though they are equivalent. f4 only means one thing. Size of the aperture. So, the lens has a 100 / 4 = 25mm diameter aperture when set at 100mm. So if we say the lens is equivalent to a 24-200mm FF lens, and the diameter of the aperture of course stays the same (25mm), the equivalent f-value of course is 200 / 25 = f8.

And optical diffraction?  The f-value is NOT there to notate optical diffraction.
First  (in the past) you were objecting to equivalent apertures because of "light per square whatever" (which is totally meaningless). You stepped off that argument to argue... diffraction? Really?

No one calls the f-value of any f4 lens f8, or f33, or f1.2. Not me either. I merely stated (correctly) that this 12-100mm f4 MFT lens in FF terms is like a 24-200mm f8 FF lens. At other times I have formulated it this way: equivalent to a 24-200mm f8 FF lens. That does not make the focal length at the wide end 24mm. Nor does it make the f-value of the lens itself f8. So your rather silly straw man argument of that cellphone lens is just... stupid.

Back to that diffraction which you do not appear to understand very well.

You can notice diffraction softening at the imaging plane. You can notice the loss of sharpness at pixel or at image level.
Lets imagine a 20mp FF sensor and a 20mp MFT sensor with a f8 and a f4 lens respectively. We take a photo with both combinations and compare on pixel level the effect of the diffraction. What do you know, we see the SAME amount of diffraction at pixel level. But pixel level maybe is just for pixel peepers, so we print out both photos at the same size and compare the effect of diffraction at image level. Damnation! Again we see the same amount of diffraction softening. Because the FF pixels are twice the width, and the sensors are twice the width.

So, even in diffraction terms, f4 on MFT is similar to f8 on FF.

And what if we use that MFT lens on FF with a 2x TC? The same diffraction. Again.

Best regards to you, Dude/Bro/Homie. And I won't go disrespecting yo mama, so we ok, rite? ;-)

dude
/d(j)uːd/
Learn to pronounce
INFORMAL•NORTH AMERICAN
noun
a man; a guy (often as a form of address).

bro noun
\ ˈbrō \
plural bros
Definition of bro
US slang
used as a friendly way of addressing a man or boy

homie
/ˈhəʊmi/
Learn to pronounce
nounINFORMAL•US
an acquaintance from one's town or neighbourhood, or a member of one's peer group or gang.

[Klaus]

Diffraction limits in megapixels for the different formats:
https://luminous-landscape.com/articleImages/images-82/TABLA3.jpg

Again - a 2 f-stop difference. There is no free lunch in MFT land.

And I still love my own 12-100mm f/4 PRO - also because it's way superior in terms of corner resolution and vignetting compared to these crappy 24-240 Canon/Sony lenses. I do not have to think of IQ - I just have it here. That applies to many MFT lenses. Many FF lenses have a great center performance and dismal borders - combined with sky high price tags. I just don't want to bother. Needless to say there's also the size/weight advantage. While in theory, FF lenses of similar "equivalent" speed could be as small, they just don't exist so that debate is purely hypothetical. Where is the FF equivalent lens of the Leica 100-400mm or Olympus 300mm f/4 IS for instance?
Conversely, you can ask how many people really buy something like a FF 85mm f/1.4? 0.1% of the FF users? 0.5%? For the vast majority it'll remains a lens illustrated in a catalog. No more.

The really relevant question isn't equivalence. It is whether you need more than MFT. I do not believe that 80% of photographers need more than MFT. Of course, everybody is free to buy whatever they want.

So as always, all things in the universe have their place and there is a place for MFT as there is one for FF. There's even one for APS-C, too. ;-)

[Brightcolours]

 Many FF lenses have a great center performance and dismal borders - combined with sky high price tags. I just don't want to bother. Needless to say there's also the size/weight advantage. While in theory, FF lenses of similar "equivalent" speed could be as small, they just don't exist so that debate is purely hypothetical. Where is the FF equivalent lens of the Leica 100-400mm or Olympus 300mm f/4 IS for instance?
Conversely, you can ask how many people really buy something like a FF 85mm f/1.4? 0.1% of the FF users? 0.5%? For the vast majority it'll remains a lens illustrated in a catalog. No more.

The really relevant question isn't equivalence. It is whether you need more than MFT. I do not believe that 80% of photographers need more than MFT. Of course, everybody is free to buy whatever they want.

So as always, all things in the universe have their place and there is a place for MFT as there is one for FF. There's even one for APS-C, too. ;-)

The "dismal" borders are a result of higher sample rate (higher resolution sensor lens tests) and your simple sharpening step for the MTF chart images, which gives the smaller  format test borders a boost and the FF borders a kick, mostly. 
Like I pointed out at the beginning of this thread, you compared the manufacturer MTF curves of the Oly 12-100mm f4 and the RF 24-240mm f4-6.3 IS USM, but both are "wide open", and that Oly is equivalent to a 24-200mm f8 lens. I bet that the corners of this 24-240mm are pretty close to what that Oly does.

There is no that small aperture equivalent for the lenses you mention, just as there are no smaller sensor format equivalents for FF tele lenses either. Use the tool that offers what you need.

Your question of how many FF shooting people buy a 85mm f1.4... Most FF shooters have one or more of the following lenses: 70-200mm f4, 70-200mm f2.8, 85mm f1.8 (or yes, f1.4 or f1.2), 50mm f1.4, 35mm f2 or f1.4 (or now f1.2), 24mm f1.8 or f1.4, 16-35mm f2.8, 135mm f2 or f1.8, 500mm f4, 200mm f2.

So, most FF shooters have at least one lens which has little or no equivalent for smaller sensor platforms.

Like I said before, use the tool you need.

[Klaus]

Your sharpening argument is lame.

To start with - we use sharpening that is slightly lower than the default sharpening in your camera or RAW converter.
Thus we do the very same thing that all users are doing.
If you consider the amount of sharpening a flawed approach, then the default sharpening is even worse - please call the manufacturer of your camera and tell them to fix this.

Also - the amount of sharpening is pretty much the same across all systems - which negates your argument that only FF is affected.

[Brightcolours]

Your sharpening argument is lame.

To start with - we use sharpening that is slightly lower than the default sharpening in your camera or RAW converter.
Thus we do the very same thing that all users are doing.
If you consider the amount of sharpening a flawed approach, then the default sharpening is even worse - please call the manufacturer of your camera and tell them to fix this.

Also - the amount of sharpening is pretty much the same across all systems - which negates your argument that only FF is affected.

To start with, it is not lame. 

You use a totally undocumented/undisclosed sharpening amount, and that it impacts results is evident in high resolution tests (Sony and Canon FF tests).

What you HAVE disclosed is that you use a very blunt way of sharpening, a simple USM. This will elevate sharpness from sharp parts a lot, and progressively less the less sharp things are, making differences more pronounced than they are. This is not a problem if things were equal across all tests, but they are not. Higher resolution sensors get hit twice... For having a bit less sharp values not sharpened at all and the center parts sharpened a lot (1st border hit), and with lower resolution tests like those from MTF having equally less sharp parts being boosted due to the much lower sampling rate, making for certain individuals claiming FF lenses having "dismal borders".

You in effect are blaming FF borders for the lower sample rate of other cameras.

It would be interesting to see the difference of sharpened and unsharpened MTF results with the 42mp Sony and/or 50mo Canon.

[Klaus]

Nothing you outlined explains why FF lenses are reacting worse to the procedure than lenses of a smaller format.
USM has the inverse effect on the numbers as an AA filter - no more, no less.
USM does, of course, boost the center because the center is always better - and it does so regardless of the image format.
It still doesn't explain why, on average, FF lenses are less receptive to USM at the borders than smaller format lenses e.g. the MFT tests have roughly the same pixel density as the EOS 5Ds R tests.

To throw you a breadcrumb - of course, if there was a MFT sensor with the same output as a EOS 5Ds R, the border results would tank massively compared to the center as well.
That just happens if you throw more and more sensor resolution at lenses that don't improve as fast as sensors do.
Megapixels simply follow the rule of about diminishing return of investment. So the different formats have different reasonable megapixel peaks.
So if you'd like to correct me, it's not about the lenses being crappy, it's about throwing too many megapixels at them.

Where this "reasonable" peak resides is subject to debate, of course. But for FF it is not 4x as high as for MFT, it is less than that.
This is all no news anyway. Medium format lenses are typically less sharp than full format lenses as well.
It's also the reason why smartphone images aren't quite as terrible as you might expect just from the sensor format and those tiny lenses.

[Brightcolours]

Nothing you outlined explains why FF lenses are reacting worse to the procedure than lenses of a smaller format.
USM has the inverse effect on the numbers as an AA filter - no more, no less.
USM does, of course, boost the center because the center is always better - and it does so regardless of the image format.
It still doesn't explain why, on average, FF lenses are less receptive to USM at the borders than smaller format lenses e.g. the MFT tests have roughly the same pixel density as the EOS 5Ds R tests.

To throw you a breadcrumb - of course, if there was a MFT sensor with the same output as a EOS 5Ds R, the border results would tank massively compared to the center as well.
That just happens if you throw more and more sensor resolution at lenses that don't improve as fast as sensors do.
Megapixels simply follow the rule of about diminishing return of investment. So the different formats have different reasonable megapixel peaks.
So if you'd like to correct me, it's not about the lenses being crappy, it's about throwing too many megapixels at them.

Where this "reasonable" peak resides is subject to debate, of course. But for FF it is not 4x as high as for MFT, it is less than that.
This is all no news anyway. Medium format lenses are typically less sharp than full format lenses as well.
It's also the reason why smartphone images aren't quite as terrible as you might expect just from the sensor format and those tiny lenses.

The higher sampling rate explains it already. So yes, your opinion of "dismal borders for FF lenses" is what I like to counter.

Back to an earlier point in the discussion. I wrote this:

I doubt that for 3 reasons.

1. The center resolution for the lens seems pretty ok wide open. So you will get more "effective resolution" on 30mp on your subject for sure, it is not like 30mp is too taxing.
   
   
2. The Canon RF 24-105 f4 24mm Canon MTF chart is not that different from this 24-240mm lens, and that 24-105mm lens did a very good job when it comes to image resolution, according to some reviewer based in Australia.
   
   
3. The charts for the Olympus lens are for.... f4 on MFT. That is equivalent to f8 on FF. The charts for the Canon lens are for f4 on 24mm, and f6.3 on 240mm.
   

 

Did you check the simulated MTF charts from Canon for the RF 24-105mm f4 vs the RF 24-240mm?
And did you look at your own MTF charts of the Oly 12-100mm f4 and RF 24-105mm f4?
Where are those "dismal borders"? Yes, the 24-105mm has less reach. But yes, it has a bigger aperture (f4 vs f8 equivalent).