# Return of Interesting article on DxO about 5D III and D800...

Started Apr 10, 2013 | Discussions
 Forum
Re: Return of Interesting article on DxO about 5D III and D800...

aftab wrote:

schmegg wrote:

aftab wrote:

......... We can say A has higher resolution. Or we can say A is sharper. Same thing.

If you wish to change the definition of resolution to merely mean how sharp something appears, then I'd agree with everything you've said here.

Otherwise - no - not the same thing.

Disclaimer: I may change my mind tomorrow morning, I am drinking wine at the moment. Australian Penfolds red wines are really nice.

My experience is that a good red will make things appear much simpler than they might actually be.

PS - I'm having a red too at the moment.

Red is gold.

Hehe. With you there brother.

Glad you're enjoying the Penfolds. Have you tried the Grange? You haven't lived till you had a Grange.

(OK - slight exaggeration there - but it's damn fine!)

Einstein said, we should make things simple, but not simpler. Maybe I did make it simpler. Yeah, when I said, it is the same thing, it is not true for scenario A. Definitions or concepts that these two entities are different work for scenario A. But scenario A is totally theoretical. It helps us to understand the concept, but that's not how we take pictures or process them. Our pictures are more like scenario B or C and that's where two concepts overlap and become indistinguishable.

Yeah - true enough.

That's what DxO have attempted (I think) to incorporate with their PMpix measurement. The very real concept that sharpness appears as resolution, even though it's not. And it's very possible to have an image that actually contains less real detail but still appears to have more detail, simply due to it being sharper.

Complain
Re: Return of Interesting article on DxO about 5D III and D800...

qianp2k wrote:

schmegg wrote:

aftab wrote:

......... We can say A has higher resolution. Or we can say A is sharper. Same thing.

If you wish to change the definition of resolution to merely mean how sharp something appears, then I'd agree with everything you've said here.

Otherwise - no - not the same thing.

Disclaimer: I may change my mind tomorrow morning, I am drinking wine at the moment. Australian Penfolds red wines are really nice.

My experience is that a good red will make things appear much simpler than they might actually be.

PS - I'm having a red too at the moment.

I am not under influence of red at the moment but my eyes still see all A samples in aftab's post not only sharper but resolve more fine details

Yes sharpness and resolution are not the same but related just as noise and detail are related that you cannot separate them.  Nevertheless DXOMark's term sharpness is not the same one you might think about that can be processed in software.

-- hide signature --

You should drink some too.

Talking about processing, we can make an image look sharper in the post by increasing the actuance without increasing the resolution. Resolution can't be increased in the post, but sharpness can be. But the fact remains that higher resolution will always make an image look sharper than a lower resolution image. In our perception detail = sharpness.

-- hide signature --

Life is short.
Travel with passion.
http://www.flickr.com/photos/catch45/

aftab's gear list:aftab's gear list
Panasonic FZ1000 Canon G1 X II Nikon D600 Canon EOS 5D Mark III Canon EOS 7D Mark II +9 more
Complain
Re: Return of Interesting article on DxO about 5D III and D800...

schmegg wrote:

aftab wrote:

schmegg wrote:

aftab wrote:

......... We can say A has higher resolution. Or we can say A is sharper. Same thing.

If you wish to change the definition of resolution to merely mean how sharp something appears, then I'd agree with everything you've said here.

Otherwise - no - not the same thing.

Disclaimer: I may change my mind tomorrow morning, I am drinking wine at the moment. Australian Penfolds red wines are really nice.

My experience is that a good red will make things appear much simpler than they might actually be.

PS - I'm having a red too at the moment.

Red is gold.

Hehe. With you there brother.

Glad you're enjoying the Penfolds. Have you tried the Grange? You haven't lived till you had a Grange.

(OK - slight exaggeration there - but it's damn fine!)

Yeah, I tried, but it's not readily available here.

Einstein said, we should make things simple, but not simpler. Maybe I did make it simpler. Yeah, when I said, it is the same thing, it is not true for scenario A. Definitions or concepts that these two entities are different work for scenario A. But scenario A is totally theoretical. It helps us to understand the concept, but that's not how we take pictures or process them. Our pictures are more like scenario B or C and that's where two concepts overlap and become indistinguishable.

Yeah - true enough.

That's what DxO have attempted (I think) to incorporate with their PMpix measurement. The very real concept that sharpness appears as resolution, even though it's not. And it's very possible to have an image that actually contains less real detail but still appears to have more detail, simply due to it being sharper.

Agreed.

-- hide signature --

Life is short.
Travel with passion.
http://www.flickr.com/photos/catch45/

aftab's gear list:aftab's gear list
Panasonic FZ1000 Canon G1 X II Nikon D600 Canon EOS 5D Mark III Canon EOS 7D Mark II +9 more
Complain
Re: not sharpness
2

John Sheehy wrote:

Mako2011 wrote:

You seem to be mixing terms and describing sharpness but calling it resolution.  Resolution only describes how much detail a camera/lens is capable of capturing — and not necessarily the quality of the detail that is captured. The problem, in these types of discussions, is that folks keep mixing related terms an using them to describe inaccurately a concept

Did you actually read my post?  It seems very unlikely, given your response.

-- hide signature --

It seems he read it perfectly.  The second you try to discuss "both types of resolution".... Your discussion was over.  There is only one type of resolution.  And one type of acutance.  You seem to miss that simple distinction.

The Davinator's gear list:The Davinator's gear list
Canon PowerShot G3 Canon PowerShot SX150 IS Canon EOS D30 Nikon D2X Fujifilm X-Pro1 +16 more
Complain
Re: not sharpness

John Sheehy wrote:

qianp2k wrote:

John Sheehy wrote:

Mako2011 wrote:

You seem to be mixing terms and describing sharpness but calling it resolution.  Resolution only describes how much detail a camera/lens is capable of capturing — and not necessarily the quality of the detail that is captured. The problem, in these types of discussions, is that folks keep mixing related terms an using them to describe inaccurately a concept

Did you actually read my post?  It seems very unlikely, given your response.

He doesn't care the quality of pixels (or detail) that's why I keep using 41mp Nokia 808 to remind him  For him, 41mp is 41mp regardless of the huge loss thru imperfect lens and loss in crop enlargement, regardless if his eyes actually can resolve details or not.

40MP pixels is and always is, 40MP.  "MPs" is the maximum number of sampling elements, regardless of potential contrast.  Sampling should, ideally, be soft, at the pixel level.  Not by having too strong an AA filter, or by having a soft lens, but by having enough pixels that pixel softness is the result.  You can not record an image without spatial distortion, if you have high contrast in the RAW capture at the pixel level.  It is impossible.  A 40MP sensor will always be able to record alternating darker and lighter lines on alternating lines of pixels, at some level of contrast, unless the AA filter or diffraction is ridiculous, in which case the noise will be much stronger than the signal.

Sure 41mp in Nokia 808 is only 41mp on paper. But there is simply no such perfect lens existed that can fully resolve that 41mp and compensate huge crop penalty (as those pixels are enlarged many times bigger to project on the same size output). I think if DXOMark ever tested it, its P-MPIx will be only 4mp at the best. I have seen 808 100% cropped that I cannot see much details when you look closely that are not washed out.

In the case of the Nokia, it doesn't seem that the system is getting much, if any, undersampling, which means that the 40MP is a good thing.  It will downsample to a much better 12MP image than a 12MP sensor, and it will be much better printed large at 40MP than it would be from a 12MP sensor.  The only downside to having 40MP is speed and storage.

I have seen DPR Connect tested several cell phone cameras including 808. I don't see 808 takes better or even much more detailed photos than iPhone 5 or Samsung SIII. The fact is that Nokia 808 or any cell phone cameras in today markets never be able to generate those photos with that levels of fine details as shown in my 12.8mp 5D with 24-105L, 17-40L and 50/1.4 at a given size said 30x20" print or 3000-pixel wide JPEG.  Otherwise please post any photos from 808 and let us see.

He denies crop penalty in other posts in other threads before (but all these concepts are related to each other)  that's why I also keep using another vivid case that nobody should buy 600mm lens that all PJs should use 300mm on 2.0x crop or even better 30mm on 20x crop, LOL.  I know he will again suggest me off-topic  But if he cannot address these two vivid cases (Nokia 808 and 600mm lens), he doesn't understand resolution or perceptual sharpness (resolution or fine details as I prefer to call)

We haven't seen the Nokia's sensor with a lens that isn't designed to sit very close to the sensor, which is probably a major reason why the 40MP images aren't as sharp at the pixel level as many other cameras.  Regardless, the 40MP still gets 40 million samples; none of them redundant.

The key factor is that no such lens ever existed or ever can be designed and manufactured as long as we still stay in glass lens that can fully resolve 41mp from the sensor. Even there is such perfect zero-lost lens ever existed, 41mp from Nokia 808 still will not be real 41mp after deduction from huge crop enlargement. It would resolve far less than 36mp D800, 22mp 5D3 or even will not resolve more than 12.8mp 5Dc.  Don’t forget crop penalty.

That's why I said there is simply no such sensor resolution as it has to go thru lens and has to face crop enlargement and crop penalty (FF also has crop penalty but just less and MF has much lesser).

-- hide signature --
-- hide signature --
Complain
Re: Return of Interesting article on DxO about 5D III and D800...

aftab wrote:

qianp2k wrote:

schmegg wrote:

aftab wrote:

......... We can say A has higher resolution. Or we can say A is sharper. Same thing.

If you wish to change the definition of resolution to merely mean how sharp something appears, then I'd agree with everything you've said here.

Otherwise - no - not the same thing.

Disclaimer: I may change my mind tomorrow morning, I am drinking wine at the moment. Australian Penfolds red wines are really nice.

My experience is that a good red will make things appear much simpler than they might actually be.

PS - I'm having a red too at the moment.

I am not under influence of red at the moment but my eyes still see all A samples in aftab's post not only sharper but resolve more fine details

Yes sharpness and resolution are not the same but related just as noise and detail are related that you cannot separate them.  Nevertheless DXOMark's term sharpness is not the same one you might think about that can be processed in software.

-- hide signature --

You should drink some too.

Talking about processing, we can make an image look sharper in the post by increasing the actuance without increasing the resolution. Resolution can't be increased in the post, but sharpness can be. But the fact remains that higher resolution will always make an image look sharper than a lower resolution image. In our perception detail = sharpness.

Sure I will pickup a bottle of RED later. I did a quick search in Google and found its price from \$11 Penfolds Shiraz/Cab Koonunga Hill to \$129 Penfolds Shiraz Rwt (I am sure there are more expensive ones). I am willing to spend more only if they can change my perceptual sharpness/detail that will last forever, or "illusion" disappears after you wake up next morning?

-- hide signature --

Life is short.
Travel with passion.
http://www.flickr.com/photos/catch45/

-- hide signature --
Complain
Re: not sharpness
2

qianp2k wrote:

The key factor is that no such lens ever existed or ever can be designed and manufactured as long as we still stay in glass lens that can fully resolve 41mp from the sensor. Even there is such perfect zero-lost lens ever existed, 41mp from Nokia 808 still will not be real 41mp after deduction from huge crop enlargement. It would resolve far less than 36mp D800, 22mp 5D3 or even will not resolve more than 12.8mp 5Dc.  Don’t forget crop penalty.

That's why I said there is simply no such sensor resolution as it has to go thru lens and has to face crop enlargement and crop penalty (FF also has crop penalty but just less and MF has much lesser).

There isn't any 'crop penalty' if the lens' image circle matches the sensor size. A lens designed for e.g. a 2/3" (4x crop) sensor can resolve much more lp/mm than any FF lens. If we take for example a 5D3 + 24-70/2.8L II and downscale the whole system by factor 4, then we'll get a really cute little 22mp DSLR  with a 6-17.5/2.8 lens that would have pretty much the same resolution as the 5D3 ("Pretty much", because diffraction complicates things a bit).

Complain
Re: I did

Mako2011 wrote:

John Sheehy wrote:

Mako2011 wrote:

You seem to be mixing terms and describing sharpness but calling it resolution.  Resolution only describes how much detail a camera/lens is capable of capturing — and not necessarily the quality of the detail that is captured. The problem, in these types of discussions, is that folks keep mixing related terms an using them to describe inaccurately a concept

Did you actually read my post?  It seems very unlikely, given your response.

I read it all many times. You said "... I don't think that there is a single meaning of resolution at all".

In fact,  Resolution only describes how much detail a camera/lens is capable of capturing. Mft is how that is measured. The other things you discussed being measured relate more to sharpness. Sharpness is not resolution.

-- hide signature --

My opinions are my own and not those of DPR or its administration. They carry no 'special' value (except to me and Lacie of course)

So, how is resolution measured? MTF-50 or MTF-20, or maybe MTF-10?

Complain
Re: Return of Interesting article on DxO about 5D III and D800...
Complain
excellent

Steen Bay wrote:

Mako2011 wrote:

John Sheehy wrote:

Mako2011 wrote:

You seem to be mixing terms and describing sharpness but calling it resolution.  Resolution only describes how much detail a camera/lens is capable of capturing — and not necessarily the quality of the detail that is captured. The problem, in these types of discussions, is that folks keep mixing related terms an using them to describe inaccurately a concept

Did you actually read my post?  It seems very unlikely, given your response.

I read it all many times. You said "... I don't think that there is a single meaning of resolution at all".

In fact,  Resolution only describes how much detail a camera/lens is capable of capturing. Mft is how that is measured. The other things you discussed being measured relate more to sharpness. Sharpness is not resolution.

-- hide signature --

My opinions are my own and not those of DPR or its administration. They carry no 'special' value (except to me and Lacie of course)

So, how is resolution measured? MTF-50 or MTF-20, or maybe MTF-10?

Great point and excellent topic for another thread.

http://www.luminous-landscape.com/tutorials/understanding-series/understanding-mtf.shtml

-- hide signature --

My opinions are my own and not those of DPR or its administration. They carry no 'special' value (except to me and Lacie of course)

Complain
Re: not sharpness

Steen Bay wrote:

qianp2k wrote:

The key factor is that no such lens ever existed or ever can be designed and manufactured as long as we still stay in glass lens that can fully resolve 41mp from the sensor. Even there is such perfect zero-lost lens ever existed, 41mp from Nokia 808 still will not be real 41mp after deduction from huge crop enlargement. It would resolve far less than 36mp D800, 22mp 5D3 or even will not resolve more than 12.8mp 5Dc.  Don’t forget crop penalty.

That's why I said there is simply no such sensor resolution as it has to go thru lens and has to face crop enlargement and crop penalty (FF also has crop penalty but just less and MF has much lesser).

There isn't any 'crop penalty' if the lens' image circle matches the sensor size. A lens designed for e.g. a 2/3" (4x crop) sensor can resolve much more lp/mm than any FF lens. If we take for example a 5D3 + 24-70/2.8L II and downscale the whole system by factor 4, then we'll get a really cute little 22mp DSLR  with a 6-17.5/2.8 lens that would have pretty much the same resolution as the 5D3 ("Pretty much", because diffraction complicates things a bit).

Actually should be 6-17.5mm/F0.7 zoom that not only not cute and small anymore but impossible to be manufactured by a material named as "glass"

That’s why I keep using 600mm lens as an example if no "crop penalty".  Nobody should buy bulky and super expensive 600mm/F4.0 lens to use on FF cameras but should use 300mm/F4.0 on 2.0x crop mFT/FT cameras (such as E-5 or EM-5) or even better 30mm/F4.0 on a 20x crop camera to achieve the same resolution when you frame the subject into the same AOV. We know Olympus tried hard and failed badly in its E-x series DSLRs (how many if any still use at sideline of NFL or Olympic games?), no mention on a 20x crop camera, LOL.

-- hide signature --
Complain
Re: Return of Interesting article on DxO about 5D III and D800...

aftab wrote:

Now, let us look at scenario B and scenario C again. In both cases A looks sharper than B. What does that mean? More resolution = more sharpness. That is resolution = sharpness in this two scenarios. And almost all scenarios are like this. So, we can actually use the terms resolution and sharpness interchangeably.

But if comparing for example the 12.7mp 5D vs. the 18mp 7D, then things get a bit more complicated, because it seems that 5D (most often, with most lenses) has the best sharpness (MTF-50?), while the 7D has the highest resolution (MTF-10 or MTF-5?).

Complain
Re: Return of Interesting article on DxO about 5D III and D800...

Steen Bay wrote:

aftab wrote:

Now, let us look at scenario B and scenario C again. In both cases A looks sharper than B. What does that mean? More resolution = more sharpness. That is resolution = sharpness in this two scenarios. And almost all scenarios are like this. So, we can actually use the terms resolution and sharpness interchangeably.

But if comparing for example the 12.7mp 5D vs. the 18mp 7D, then things get a bit more complicated, because it seems that 5D (most often, with most lenses) has the best sharpness (MTF-50?),

true.

while the 7D has the highest resolution (MTF-10 or MTF-5?).

Not necessarily. Actually with most  EF lenses 5D outresolves 7D if you frame them in the same AOV (as tested by DXOMark in either old MTF or new P-MPix unit that are two different expressing units but with the same result). Only very few lenses such as with 300L/2.8 IS II 7D/60D outresolves 5D.

-- hide signature --
Complain
Re: not sharpness
2

qianp2k wrote:

Steen Bay wrote:

qianp2k wrote:

The key factor is that no such lens ever existed or ever can be designed and manufactured as long as we still stay in glass lens that can fully resolve 41mp from the sensor. Even there is such perfect zero-lost lens ever existed, 41mp from Nokia 808 still will not be real 41mp after deduction from huge crop enlargement. It would resolve far less than 36mp D800, 22mp 5D3 or even will not resolve more than 12.8mp 5Dc.  Don’t forget crop penalty.

That's why I said there is simply no such sensor resolution as it has to go thru lens and has to face crop enlargement and crop penalty (FF also has crop penalty but just less and MF has much lesser).

There isn't any 'crop penalty' if the lens' image circle matches the sensor size. A lens designed for e.g. a 2/3" (4x crop) sensor can resolve much more lp/mm than any FF lens. If we take for example a 5D3 + 24-70/2.8L II and downscale the whole system by factor 4, then we'll get a really cute little 22mp DSLR  with a 6-17.5/2.8 lens that would have pretty much the same resolution as the 5D3 ("Pretty much", because diffraction complicates things a bit).

Actually should be 6-17.5mm/F0.7 zoom that not only not cute and small anymore but impossible to be manufactured by a material named as "glass"

The f-stop is maintained if a lens is up/downscaled, because the f-stop is the ratio between the FL and the aperture diameter (which both are scaled by the same factor).

That’s why I keep using 600mm lens as an example if no "crop penalty".  Nobody should buy bulky and super expensive 600mm/F4.0 lens to use on FF cameras but should use 300mm/F4.0 on 2.0x crop mFT/FT cameras (such as E-5 or EM-5) or even better 30mm/F4.0 on a 20x crop camera to achieve the same resolution when you frame the subject into the same AOV. We know Olympus tried hard and failed badly in its E-x series DSLRs (how many if any still use at sideline of NFL or Olympic games?), no mention on a 20x crop camera, LOL.

-- hide signature --
Complain
Re: not sharpness

Steen Bay wrote:

qianp2k wrote:

Steen Bay wrote:

qianp2k wrote:

The key factor is that no such lens ever existed or ever can be designed and manufactured as long as we still stay in glass lens that can fully resolve 41mp from the sensor. Even there is such perfect zero-lost lens ever existed, 41mp from Nokia 808 still will not be real 41mp after deduction from huge crop enlargement. It would resolve far less than 36mp D800, 22mp 5D3 or even will not resolve more than 12.8mp 5Dc.  Don’t forget crop penalty.

That's why I said there is simply no such sensor resolution as it has to go thru lens and has to face crop enlargement and crop penalty (FF also has crop penalty but just less and MF has much lesser).

There isn't any 'crop penalty' if the lens' image circle matches the sensor size. A lens designed for e.g. a 2/3" (4x crop) sensor can resolve much more lp/mm than any FF lens. If we take for example a 5D3 + 24-70/2.8L II and downscale the whole system by factor 4, then we'll get a really cute little 22mp DSLR  with a 6-17.5/2.8 lens that would have pretty much the same resolution as the 5D3 ("Pretty much", because diffraction complicates things a bit).

Actually should be 6-17.5mm/F0.7 zoom that not only not cute and small anymore but impossible to be manufactured by a material named as "glass"

The f-stop is maintained if a lens is up/downscaled, because the f-stop is the ratio between the FL and the aperture diameter (which both are scaled by the same factor).

Yeah, it's the only way to make such lens small and cut on smaller crop sensor cameras.  But they don't perform at the same level and never will.

That’s why I keep using 600mm lens as an example if no "crop penalty".  Nobody should buy bulky and super expensive 600mm/F4.0 lens to use on FF cameras but should use 300mm/F4.0 on 2.0x crop mFT/FT cameras (such as E-5 or EM-5) or even better 30mm/F4.0 on a 20x crop camera to achieve the same resolution when you frame the subject into the same AOV. We know Olympus tried hard and failed badly in its E-x series DSLRs (how many if any still use at sideline of NFL or Olympic games?), no mention on a 20x crop camera, LOL.

Then you unable to demo in above 600mm case. I am sure 300mm/F4.0 lens on 18mp mFT/FT not only far less than native 600mm/F4.0 on 18mp FF (such as 1DX), it's even less than 12.8mp 5D in resolution test that your eyes can actually resolve. 600mm on 12.8mp 5D will receive 12+ P-MPix that almost has no loss but 300mm/F4.0 lens on a 18mp 2.0x crop will only have 5-6 P-MPix if DXOMark ever tested where you will see so-called crop penalty in every aspect clearly

-- hide signature --
-- hide signature --
Complain
Re: Return of Interesting article on DxO about 5D III and D800...
1

qianp2k wrote:

Steen Bay wrote:

aftab wrote:

Now, let us look at scenario B and scenario C again. In both cases A looks sharper than B. What does that mean? More resolution = more sharpness. That is resolution = sharpness in this two scenarios. And almost all scenarios are like this. So, we can actually use the terms resolution and sharpness interchangeably.

But if comparing for example the 12.7mp 5D vs. the 18mp 7D, then things get a bit more complicated, because it seems that 5D (most often, with most lenses) has the best sharpness (MTF-50?),

true.

while the 7D has the highest resolution (MTF-10 or MTF-5?).

Not necessarily. Actually with most  EF lenses 5D outresolves 7D if you frame them in the same AOV (as tested by DXOMark in either old MTF or new P-MPix unit that are two different expressing units but with the same result). Only very few lenses such as with 300L/2.8 IS II 7D/60D outresolves 5D.

-- hide signature --

But what if we could compare the MTF-10 er MTF-5 values (which we unfortunately can't anymore)? Then I think that the 7D would win, because it has quite a bit more MPs.

Complain
Re: Return of Interesting article on DxO about 5D III and D800...

Steen Bay wrote:

qianp2k wrote:

Steen Bay wrote:

aftab wrote:

Now, let us look at scenario B and scenario C again. In both cases A looks sharper than B. What does that mean? More resolution = more sharpness. That is resolution = sharpness in this two scenarios. And almost all scenarios are like this. So, we can actually use the terms resolution and sharpness interchangeably.

But if comparing for example the 12.7mp 5D vs. the 18mp 7D, then things get a bit more complicated, because it seems that 5D (most often, with most lenses) has the best sharpness (MTF-50?),

true.

while the 7D has the highest resolution (MTF-10 or MTF-5?).

Not necessarily. Actually with most  EF lenses 5D outresolves 7D if you frame them in the same AOV (as tested by DXOMark in either old MTF or new P-MPix unit that are two different expressing units but with the same result). Only very few lenses such as with 300L/2.8 IS II 7D/60D outresolves 5D.

-- hide signature --

But what if we could compare the MTF-10 er MTF-5 values (which we unfortunately can't anymore)? Then I think that the 7D would win, because it has quite a bit more MPs.

In theory maybe.  But it's a matter of our eyes can resolve or not that's all DXOMark test about, a paper resolution vs real resolution after deducting noise/grain, pixel magnification...  It’s a matter of perceptual sharpness (resolution) human eyes can perceive.

http://www.cambridgeincolour.com/tutorials/lens-quality-mtf-resolution.htm

-- hide signature --
Complain
Re: Return of Interesting article on DxO about 5D III and D800...

qianp2k wrote:

Steen Bay wrote:

qianp2k wrote:

Steen Bay wrote:

aftab wrote:

Now, let us look at scenario B and scenario C again. In both cases A looks sharper than B. What does that mean? More resolution = more sharpness. That is resolution = sharpness in this two scenarios. And almost all scenarios are like this. So, we can actually use the terms resolution and sharpness interchangeably.

But if comparing for example the 12.7mp 5D vs. the 18mp 7D, then things get a bit more complicated, because it seems that 5D (most often, with most lenses) has the best sharpness (MTF-50?),

true.

while the 7D has the highest resolution (MTF-10 or MTF-5?).

Not necessarily. Actually with most  EF lenses 5D outresolves 7D if you frame them in the same AOV (as tested by DXOMark in either old MTF or new P-MPix unit that are two different expressing units but with the same result). Only very few lenses such as with 300L/2.8 IS II 7D/60D outresolves 5D.

-- hide signature --

But what if we could compare the MTF-10 er MTF-5 values (which we unfortunately can't anymore)? Then I think that the 7D would win, because it has quite a bit more MPs.

In theory maybe.  But it's a matter of our eyes can resolve or not that's all DXOMark test about, a paper resolution vs real resolution after deducting noise/grain, pixel magnification...  It’s a matter of perceptual sharpness (resolution) human eyes can perceive.

http://www.cambridgeincolour.com/tutorials/lens-quality-mtf-resolution.htm

-- hide signature --

Yes, it's a matter of what the human eye can perceive, so how about comparing the resolution test chart shots in DPR's 5D and 7D reviews? (available for download). Haven't checked, but as far as I remember, then the 7D wins.

Complain
Re: Return of Interesting article on DxO about 5D III and D800...

Steen Bay wrote:

qianp2k wrote:

Steen Bay wrote:

qianp2k wrote:

Steen Bay wrote:

aftab wrote:

Now, let us look at scenario B and scenario C again. In both cases A looks sharper than B. What does that mean? More resolution = more sharpness. That is resolution = sharpness in this two scenarios. And almost all scenarios are like this. So, we can actually use the terms resolution and sharpness interchangeably.

But if comparing for example the 12.7mp 5D vs. the 18mp 7D, then things get a bit more complicated, because it seems that 5D (most often, with most lenses) has the best sharpness (MTF-50?),

true.

while the 7D has the highest resolution (MTF-10 or MTF-5?).

Not necessarily. Actually with most  EF lenses 5D outresolves 7D if you frame them in the same AOV (as tested by DXOMark in either old MTF or new P-MPix unit that are two different expressing units but with the same result). Only very few lenses such as with 300L/2.8 IS II 7D/60D outresolves 5D.

-- hide signature --

But what if we could compare the MTF-10 er MTF-5 values (which we unfortunately can't anymore)? Then I think that the 7D would win, because it has quite a bit more MPs.

In theory maybe.  But it's a matter of our eyes can resolve or not that's all DXOMark test about, a paper resolution vs real resolution after deducting noise/grain, pixel magnification...  It’s a matter of perceptual sharpness (resolution) human eyes can perceive.

http://www.cambridgeincolour.com/tutorials/lens-quality-mtf-resolution.htm

-- hide signature --

Yes, it's a matter of what the human eye can perceive, so how about comparing the resolution test chart shots in DPR's 5D and 7D reviews? (available for download). Haven't checked, but as far as I remember, then the 7D wins.

I don't think so with most EF lenses, 5D gains more with inferior lenses if you test by framing them in the same AOV.  I did such test other day (and will do again) that show 5D has resolution advantage except with the best lens 24-70L II in very close distance (macro mode) against a dollar bill but that is a very small center area (and 5D wins in edges/corners).  In real world outdoor test, 5D wins clearly.  I think DXOMark uses average frame resolution to calculate its DXOMark number.

-- hide signature --
Complain
Re: Return of Interesting article on DxO about 5D III and D800...

aftab wrote:

qianp2k wrote:

schmegg wrote:

aftab wrote:

......... We can say A has higher resolution. Or we can say A is sharper. Same thing.

If you wish to change the definition of resolution to merely mean how sharp something appears, then I'd agree with everything you've said here.

Otherwise - no - not the same thing.

Disclaimer: I may change my mind tomorrow morning, I am drinking wine at the moment. Australian Penfolds red wines are really nice.

My experience is that a good red will make things appear much simpler than they might actually be.

PS - I'm having a red too at the moment.

I am not under influence of red at the moment but my eyes still see all A samples in aftab's post not only sharper but resolve more fine details

Yes sharpness and resolution are not the same but related just as noise and detail are related that you cannot separate them.  Nevertheless DXOMark's term sharpness is not the same one you might think about that can be processed in software.

-- hide signature --

You should drink some too.

Talking about processing, we can make an image look sharper in the post by increasing the actuance without increasing the resolution. Resolution can't be increased in the post, but sharpness can be. But the fact remains that higher resolution will always make an image look sharper than a lower resolution image. In our perception detail = sharpness.

To me, "sharpness" has two meanings. First, "sharpness" is just the visible result an image coming close to the highest "resolution" a camera can produce, and as such, is just a byproduct of resolution. The second meaning is the artificial application of increased local contrast, IOW PP "sharpening". So you can get "sharpness" through resolution, but not vice-versa.

Resolution is what you work with at the moment of image capture. Sharpness is what you have to work with if the capture didn't come very close to maxing out your camera.

Red wine definitely results in a loss of sharpness, and for that, there is no resolution.

SB

Complain
 Forum