Interesting article on DxO about 5D III and D800 resolving power

Started Apr 4, 2013 | Discussions
schmegg
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Re: Interesting article on DxO about 5D III and D800 resolving power
In reply to Mikael Risedal, Apr 7, 2013

Mikael Risedal wrote:

LOL? They are not hard sharpen for print etc.

They certainly are sharpened though.

I have no doubt that there will be more detail resolved in the D800 image. And I rather think that your example shows it anyway - although both images (in the second set) look pretty awful due to oversharpening. No offense intended.

Nevermind. I'd just find the comparison a whole lot more useful if the images had not been 'manipulated'. ie. with the sharpening slider set to zero on both files. Any chance of that?

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John Sheehy
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Re: Interesting article on DxO about 5D III and D800 resolving power
In reply to Mike CH, Apr 7, 2013

Mike CH wrote:

John Sheehy wrote:

There was a time when resolution was often described in lines or line pairs per millimeter.  Remember millimeter?  How confusing was that?

Yes, I do remember. No, I don't find it confusing. The problem comes when it is misrepresented or in the wrong context.

Unqualified "per sensor" measurements are just guilty as unqualified "per mm" measurements.

To use an analogy from somewhere else: it is quite obvious, isn't it, that a cars fuel consumption can be measured in square miles, yes?

That's pure hyperbole.  That is an abstraction that has nothing to do with elemental concerns.  Yeah, you can multiply by the width of the car, or drive in a spiral where your left tires follow the tracks of your right tires and see how much of a circle you can cover with a unit of gas, but both are extremely unlikely a need, compared to sensor or film performance per mm.

IMO, the least-confused people are those who see the lens first, as an analog projection device with its own set of imperfections, the FOV determined by the sensor size, and then the imaging quality per unit of sensor area.  Every other way of looking at things can be extended from this, with a minimal amount of confusion.

Ehm, yes?!? So how do you get from there, in a minimal way, to a practical comparison of (whatever measure you favour of) resolution at same FOV?

And why not go there directly?

Nothing wrong with quoting such things directly, but one should understand what is going on to create the frame, if one is to avoid coming to false conclusions extrapolating from that information, such as when a lens is not available to create the FOV needed for one sensor size.

I've seen so many people come to false conclusions over the years, because they do not understand the elemental issues of image capture, and can only grasp simple, high abstractions, such as this new "perceptual megapixel" nonsense.  Quoting resolution at a single contrast threshold may have been fine for film, since the contrast roll-off tail would be fairly predictable, but for discrete gridded sampling, it is very misleading, IMO, because you do not know what the contrast vs resolution curve does on either side of the chosen contrast threshold.  You could have a lot of lower-contrast resolution in a low-ISO capture that is good enough to use with sharpening, giving more resolution at a target contrast level in the output, at resolution levels impossible with a system that scored higher PMP.

starting from a position that fails to distinguish between relatives and absolutes.

Are you saying that there is no absolute measurement of resolution which can be used at the same FOV?

No.  Both the sensor alone, and the sensor with a given lens, aperture, and focus distance have their own potentials which can be measured, relative only to their frames, regardless of size.  PMP is not a very thorough measure of that, however.

My practical interest is simple. Say I've taken an image with my current system of a given scene with a given composition, framing and FOV. Could I have gotten a better result IQ-wise (sharper, more detail, better colour rendition) with a different system? Measures which can't answer that question are of, at most, secondary interest to.

Then they are of secondary interest to you.  They are of secondary interest to me, too, if I need a wide FOV and focal length limitations are not an issue.  That tells just half of the story though, as far as all of my interests go.  And, I think I would rather have a 50MP sensor and lens that scores 32PMP than a 36MP sensor that scores 35PMP with the same FOV.  In fact, any sensor that performs PMP close to their true MP count has potential aliasing, and is a sign that the sensor has far too low a pixel density for that lens (or the AA filter is too weak for that lens, but more pixels is better solution than a weaker AA filter).

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Mikael Risedal
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Re: Interesting article on DxO about 5D III and D800 resolving power
In reply to schmegg, Apr 7, 2013

schmegg wrote:

Mikael Risedal wrote:

LOL? They are not hard sharpen for print etc.

They certainly are sharpened though.

I have no doubt that there will be more detail resolved in the D800 image. And I rather think that your example shows it anyway - although both images (in the second set) look pretty awful due to oversharpening. No offense intended.

Nevermind. I'd just find the comparison a whole lot more useful if the images had not been 'manipulated'. ie. with the sharpening slider set to zero on both files. Any chance of that?

my dear man , do you think that is over sharpening for a glossy magazine?

take a look at the jaggies in comparison

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schmegg
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Re: Interesting article on DxO about 5D III and D800 resolving power
In reply to Mikael Risedal, Apr 7, 2013

Mikael Risedal wrote:

schmegg wrote:

Mikael Risedal wrote:

LOL? They are not hard sharpen for print etc.

They certainly are sharpened though.

I have no doubt that there will be more detail resolved in the D800 image. And I rather think that your example shows it anyway - although both images (in the second set) look pretty awful due to oversharpening. No offense intended.

Nevermind. I'd just find the comparison a whole lot more useful if the images had not been 'manipulated'. ie. with the sharpening slider set to zero on both files. Any chance of that?

my dear man , do you think that is over sharpening for a glossy magazine?

If you intended to print what you have presented here as the whole image - yes.

take a look at the jaggies in comparison

Sure - they show the inability of both sensors to render the actual scene detail.

Why not just show both the 100% crops unsharpened?

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Mike CH
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Re: Don't get your meaning?
In reply to John Sheehy, Apr 7, 2013

John Sheehy wrote:

Mike CH wrote:

I get that, no problem. It is real obvious that there are various definitions of resolution and various ways to measure said resolution.

What I don't get is, of what practical interest are those (various) measurements at all, if they don't compare at the same FOV?

FOV is irrelevant when you have the longest lens you can manage to use, but it is not long enough.  When you are focal length limited, all that matters is qualities of a recording surface (film or sensor) per unit of sensor area, or in lines per mm to look at it in one dimension, for resolution, at various contrasts (but resolutions are usually only stated at a single contrast).

Ah, I am not focal length limited. 80% of my images are below 100mm.

FF sensors fall flat on their face, especially Canon ones at low ISOs, when their hard crops have to compete the smallest compact sensors placed behind the lens.

Yes, FF are not optimal for birding, APS-C might be better for that. That is not really news

Since you are so fond of absolute measures, you do know, right, that the absolute, logical argument behind your rationale is actually provably wrong?

So far, people have been saying, these measurements exist. Yes, thank you - I knew that

Nobody has so far (that I have seen) eyplained of what practical use they are to a photographer. They are of interest to an engineer, yes, but the practical use I have not seen explained, yet.

We are creatures of illusion.  What seems to be the case to our eyes, is often wrong, because we fail to adjust for context.  If we find measurements that we can trust, then we can have "seeing eye dogs" to walk us through our illusions as we make decisions.

How can I trust measurements which I cannot compare in a practical situation?

If your whole argument is based on the premise that comparing at same FOV is not always possible because of being focal length limited, then I can at last see where you are coming from.

I don't think it matters much, though, in practical terms. This thread started out from a comparison between two systems which are quite similar in the available focal lengths. Thus in most cases comparisons at same FOV are quite possible.

Regards, Mike

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Rick Knepper
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Re: resolution
In reply to Mikael Risedal, Apr 7, 2013

Mikael Risedal wrote:

Same or not same lens, here is D800 with sigma 35/1,4 F-5,6  and one of my 5dmk2 with canon 35/1,4  F5.6  Below X there are a bicycle basket and the white net can be seen clearly with d800. crop

In dpreview test picture there are also lot of details , like this pattern

5dmk3 can not resolve the pattern as the other cameras

I dunno. I don't like screenshots as a way to compare. So, I downloaded the 5D3 and D800E RAWs and converted to tiffs 1.) @100% and 2.) at the file size I commonly use, 1800x1200 px (occupies roughly the same area on my NEC 2690 monitor's surface as a 13x19 print).

At 100%, while I will stop short of agreeing that the 5D3 capture fails to resolve detail, the D800E does resolve detail more clearly. Maybe this is merely a difference in distinction and fine distinction. But, this should come as no surprise even to died-in-the wool Canon fanbois when they aren't currently under the influence...

With both images downsized to 1800x1200, some of the visible detail appears to evaporate but not completely. The D800E still beats the 5D3 even with the 5D3's characteristically darker contrast that seems to fool some folks into thinking it has resolved more detail than it has. You have to lean in but detail such as the texture on walls are rendered more realistically in the D800E. Such micro-detail adds to the/my over-all perception of a photo-realistic image even though the detail may appear trivial to others when comparing a section without looking at the whole (which of course, this detail may yet get obliterated with moderate and/or indiscriminate PPing).

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schmegg
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Re: Don't get your meaning?
In reply to Mike CH, Apr 7, 2013

Mike CH wrote:

Yes, FF are not optimal for birding, APS-C might be better for that. That is not really news

Have you stopped to think why that might be?

(hint: it has nothing to do with sensor size - unlike what you've just said)

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Mikael Risedal
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Re: Interesting article on DxO about 5D III and D800 resolving power
In reply to schmegg, Apr 7, 2013

schmegg wrote:

Mikael Risedal wrote:

schmegg wrote:

Mikael Risedal wrote:

LOL? They are not hard sharpen for print etc.

They certainly are sharpened though.

I have no doubt that there will be more detail resolved in the D800 image. And I rather think that your example shows it anyway - although both images (in the second set) look pretty awful due to oversharpening. No offense intended.

Nevermind. I'd just find the comparison a whole lot more useful if the images had not been 'manipulated'. ie. with the sharpening slider set to zero on both files. Any chance of that?

my dear man , do you think that is over sharpening for a glossy magazine?

If you intended to print what you have presented here as the whole image - yes.

take a look at the jaggies in comparison

Sure - they show the inability of both sensors to render the actual scene detail.

Why not just show both the 100% crops unsharpened?

we have different views what is over sharpening and to what purpose.

here are crops and the difference between d800 and 5dmk2

and 5dmk2 can not reproduce the Peab sign

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Mikael Risedal
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Re: Interesting article on DxO about 5D III and D800 resolving power
In reply to Mikael Risedal, Apr 7, 2013

sorry wrong aperture from canon

here is 5,6 from both Cameras and the Peab sign

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schmegg
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Re: Interesting article on DxO about 5D III and D800 resolving power
In reply to Mikael Risedal, Apr 7, 2013

Mikael Risedal wrote:

schmegg wrote:

Mikael Risedal wrote:

schmegg wrote:

Mikael Risedal wrote:

LOL? They are not hard sharpen for print etc.

They certainly are sharpened though.

I have no doubt that there will be more detail resolved in the D800 image. And I rather think that your example shows it anyway - although both images (in the second set) look pretty awful due to oversharpening. No offense intended.

Nevermind. I'd just find the comparison a whole lot more useful if the images had not been 'manipulated'. ie. with the sharpening slider set to zero on both files. Any chance of that?

my dear man , do you think that is over sharpening for a glossy magazine?

If you intended to print what you have presented here as the whole image - yes.

take a look at the jaggies in comparison

Sure - they show the inability of both sensors to render the actual scene detail.

Why not just show both the 100% crops unsharpened?

we have different views what is over sharpening and to what purpose.

here are crops and the difference between d800 and 5dmk2

and 5dmk2 can not reproduce the Peab sign

Thanks - even though they are quite small - I find them more useful.

And it's clear to see the difference. Not great - but certainly there.

BTW - re sharpening ..

I understand that the D800 will require a different amount of sharpening to the 5D3. I'm familiar with this, and that's why I found it useful to see the unsharpened images. It's a better indication of what one would start with off the camera.

Cheers - and no offense intended. I appreciate you taking the time to post them.

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Mike CH
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Re: Interesting article on DxO about 5D III and D800 resolving power
In reply to John Sheehy, Apr 7, 2013

John Sheehy wrote:

Mike CH wrote:

John Sheehy wrote:

There was a time when resolution was often described in lines or line pairs per millimeter.  Remember millimeter?  How confusing was that?

Yes, I do remember. No, I don't find it confusing. The problem comes when it is misrepresented or in the wrong context.

Unqualified "per sensor" measurements are just guilty as unqualified "per mm" measurements.

To use an analogy from somewhere else: it is quite obvious, isn't it, that a cars fuel consumption can be measured in square miles, yes?

That's pure hyperbole.  That is an abstraction that has nothing to do with elemental concerns.  Yeah, you can multiply by the width of the car, or drive in a spiral where your left tires follow the tracks of your right tires and see how much of a circle you can cover with a unit of gas, but both are extremely unlikely a need, compared to sensor or film performance per mm.

Ehm

Hint: What SI unit do you end with if you reduce liter per kilometer to the simpelst possible term?

IMO, the least-confused people are those who see the lens first, as an analog projection device with its own set of imperfections, the FOV determined by the sensor size, and then the imaging quality per unit of sensor area.  Every other way of looking at things can be extended from this, with a minimal amount of confusion.

Ehm, yes?!? So how do you get from there, in a minimal way, to a practical comparison of (whatever measure you favour of) resolution at same FOV?

And why not go there directly?

Nothing wrong with quoting such things directly, but one should understand what is going on to create the frame, if one is to avoid coming to false conclusions extrapolating from that information, such as when a lens is not available to create the FOV needed for one sensor size.

I've seen so many people come to false conclusions over the years, because they do not understand the elemental issues of image capture, and can only grasp simple, high abstractions, such as this new "perceptual megapixel" nonsense.  Quoting resolution at a single contrast threshold may have been fine for film, since the contrast roll-off tail would be fairly predictable, but for discrete gridded sampling, it is very misleading, IMO, because you do not know what the contrast vs resolution curve does on either side of the chosen contrast threshold.  You could have a lot of lower-contrast resolution in a low-ISO capture that is good enough to use with sharpening, giving more resolution at a target contrast level in the output, at resolution levels impossible with a system that scored higher PMP.

Yes. I actually quite agree with your reasoning. I just cannot see the practical use of it.

Or, in other words, given your favourite measurements for two different systems, one FF, one APS-C, with lenses selected to give the same FOV, how do I get from your system of measurements to one which will answer my question about which system would have given me the better result? (Same framing, composition, FOV etc in both cases).

Could you walk us through the derivation?

starting from a position that fails to distinguish between relatives and absolutes.

Are you saying that there is no absolute measurement of resolution which can be used at the same FOV?

No.  Both the sensor alone, and the sensor with a given lens, aperture, and focus distance have their own potentials which can be measured, relative only to their frames, regardless of size.  PMP is not a very thorough measure of that, however.

Ah, so let us not use PMP. Let us use another measurement as long as it can be used to compare across systems with same FOV. Which would be your recommendation?

You might have been thinking that I was arguing in favor of PMP?

If so, then no, sorry, that was not the intention. My intention was to argue for a need to compare at same FOV, as a reaction to my feeling that several people in this thread seemed to indicate that a measurement of the sensors ability to handle an image on the focal plane was the end-all-be-all of sensor measurements.

My practical interest is simple. Say I've taken an image with my current system of a given scene with a given composition, framing and FOV. Could I have gotten a better result IQ-wise (sharper, more detail, better colour rendition) with a different system? Measures which can't answer that question are of, at most, secondary interest to.

Then they are of secondary interest to you.  They are of secondary interest to me, too, if I need a wide FOV and focal length limitations are not an issue.  That tells just half of the story though, as far as all of my interests go.

Different interests, different needs.

If I have to take an image of a bird, it had better be stuffed

And, I think I would rather have a 50MP sensor and lens that scores 32PMP than a 36MP sensor that scores 35PMP with the same FOV.  In fact, any sensor that performs PMP close to their true MP count has potential aliasing, and is a sign that the sensor has far too low a pixel density for that lens (or the AA filter is too weak for that lens, but more pixels is better solution than a weaker AA filter).

That makes sense to me.

Regards, Mike

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Mikael Risedal
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Re: Interesting article on DxO about 5D III and D800 resolving power
In reply to schmegg, Apr 7, 2013

schmegg wrote:

Mikael Risedal wrote:

schmegg wrote:

Mikael Risedal wrote:

schmegg wrote:

Mikael Risedal wrote:

LOL? They are not hard sharpen for print etc.

They certainly are sharpened though.

I have no doubt that there will be more detail resolved in the D800 image. And I rather think that your example shows it anyway - although both images (in the second set) look pretty awful due to oversharpening. No offense intended.

Nevermind. I'd just find the comparison a whole lot more useful if the images had not been 'manipulated'. ie. with the sharpening slider set to zero on both files. Any chance of that?

my dear man , do you think that is over sharpening for a glossy magazine?

If you intended to print what you have presented here as the whole image - yes.

take a look at the jaggies in comparison

Sure - they show the inability of both sensors to render the actual scene detail.

Why not just show both the 100% crops unsharpened?

we have different views what is over sharpening and to what purpose.

here are crops and the difference between d800 and 5dmk2

and 5dmk2 can not reproduce the Peab sign

Thanks - even though they are quite small - I find them more useful.

And it's clear to see the difference. Not great - but certainly there.

BTW - re sharpening ..

I understand that the D800 will require a different amount of sharpening to the 5D3. I'm familiar with this, and that's why I found it useful to see the unsharpened images. It's a better indication of what one would start with off the camera.

Cheers - and no offense intended. I appreciate you taking the time to post them.

you can look at the first pictues and halos etc, they are not over sharped and go to glossy print magazine, they need even more sharpening, do not confuse the results with what you se on the monitor or here with a print results.

the next pictures are sharpening as Dpreview 100 0,6 0  and  to se them on a monitor

there a bit more details in d800 and if the file is down sized to 5dmk2, 3 the results from d800 is cleaner surface , less jaggies  etc.

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Mike CH
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Re: Don't get your meaning?
In reply to schmegg, Apr 7, 2013

schmegg wrote:

Mike CH wrote:

Yes, FF are not optimal for birding, APS-C might be better for that. That is not really news

Have you stopped to think why that might be?

Do I get a brownie point if I mumble something about photosite density and the subsequent better ability to crop on top of the already better FOV? Better edge separation due to closer photosites with less non-photosize space between them, and stuff like that?

(hint: it has nothing to do with sensor size - unlike what you've just said)

I don't think I said that it has anything to do with the size as such. I mentioned two different sensor formats, which amongst other thingsare differentiated by size.

Regards, Mike

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Mike CH
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Re: Interesting article on DxO about 5D III and D800 resolving power
In reply to David Hull, Apr 7, 2013

David Hull wrote:

But did you really need DxO to tell you this? I doubt it. The thing that I find surprising is how many people seem to be surprised to figure out that if you want to get the most out of a good imaging system, you have to use a good lens.

Yeah, sometimes common sense is just not that common.

What I found interesting was the observation that with a 'common set of lenses' the differences weren't that large. I would have a larger difference.

Regards, Mike

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schmegg
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Re: Don't get your meaning?
In reply to Mike CH, Apr 7, 2013

Mike CH wrote:

schmegg wrote:

Mike CH wrote:

Yes, FF are not optimal for birding, APS-C might be better for that. That is not really news

Have you stopped to think why that might be?

Do I get a brownie point if I mumble something about photosite density and the subsequent better ability to crop on top of the already better FOV? Better edge separation due to closer photosites with less non-photosize space between them, and stuff like that?

(hint: it has nothing to do with sensor size - unlike what you've just said)

I don't think I said that it has anything to do with the size as such. I mentioned two different sensor formats, which amongst other thingsare differentiated by size.

It's very simple TBH.

Given the same quality of optics ...

If you wish to determine which of two sensors will resolve more detail by comparing using the FOV - then it's (generally) the sensor with the most pixels.

If you wish to determine which of two sensors will resolve more detail from the same image detail projected onto it - then it's (generally) the sensor with the highest pixel density.

However ...

If you wish to consider 'false' detail (such as artifacts that have high acutance) as detail, then pixel size will come into play.

Just like you said - which leaves me wondering why you asked!  

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Mike CH
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Re: Don't get your meaning?
In reply to schmegg, Apr 7, 2013

schmegg wrote:

Given the same quality of optics ...

Reminds me of an old joke about how to tell mathematicians and engineers apart...

If you wish to determine which of two sensors will resolve more detail by comparing using the FOV - then it's (generally) the sensor with the most pixels.

If you wish to determine which of two sensors will resolve more detail from the same image detail projected onto it - then it's (generally) the sensor with the highest pixel density.

However ...

If you wish to consider 'false' detail (such as artifacts that have high acutance) as detail, then pixel size will come into play.

That is all very true. And I do have at least an inkling of an idea about that stuff

Just like you said - which leaves me wondering why you asked!  

Which leaves me wondering, what did you think that I asked?

My intention was to question the apparent insistence that comparisons at same FOV are for weenies.

Regards, Mike

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Re: Don't get your meaning?
In reply to Mike CH, Apr 7, 2013

Mike CH wrote:

schmegg wrote:

Given the same quality of optics ...

Reminds me of an old joke about how to tell mathematicians and engineers apart...

If you wish to determine which of two sensors will resolve more detail by comparing using the FOV - then it's (generally) the sensor with the most pixels.

If you wish to determine which of two sensors will resolve more detail from the same image detail projected onto it - then it's (generally) the sensor with the highest pixel density.

However ...

If you wish to consider 'false' detail (such as artifacts that have high acutance) as detail, then pixel size will come into play.

That is all very true. And I do have at least an inkling of an idea about that stuff

Just like you said - which leaves me wondering why you asked!  

Which leaves me wondering, what did you think that I asked?

My intention was to question the apparent insistence that comparisons at same FOV are for weenies.

Hehe.

It's not really an "insistence", but more a practical concern.

You see, when people start arguing about "which sensor can resolve more detail", they invariably resort to 100% pixel view to 'show' the difference.

So, if one intends to compare at pixel level, then one should ensure that the pixels have been presented with the same detail to record to begin with - otherwise the comparison is completely inane.

Of course - the key to all this is subject distance and lens design (and that's where FF has the main advantage when you start talking about FOV comparisons).

But these FOV comparisons do not allow one to determine which sensor can resolve more detail at all - simply which sensor can be used more effectively in that particular situation - and the converse may be said in different situations in this respect!

BTW - I'm actually an engineer.

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Re: Don't get your meaning?
In reply to schmegg, Apr 7, 2013

schmegg wrote:

Given the same quality of optics ...

There is a small problem with that assumption. You want the same relative quality, i.e., the smaller lens to project a scaled down image with no loss of detail. It is not happening. As much as I like Noikia's 808 41 mp small sensor, their phone cannot beat a 40mp MF system. Also, it cannot do, say f/4 FF eq., and as such it is more prone to diffraction since its lens (it goes to something like f/7-f/8, the crop factor is about 3.5).

Nokia 808 vs. Pentax 645. Almost the same pixel count. The same resolution, right?

Source

The MF shot is at 40mm eq., and the Nokia - at 28mm. He moved a bit to get similar framing for some of the elements.

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schmegg
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Re: Don't get your meaning?
In reply to Just another Canon shooter, Apr 7, 2013

Just another Canon shooter wrote:

schmegg wrote:

Given the same quality of optics ...

There is a small problem with that assumption.

For sure. See above.

And quite honestly, we were talking about FF and crop comparisons. Looking at those images, I'd say the phone has actually done remarkably well TBH!

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Just another Canon shooter
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Re: Don't get your meaning?
In reply to schmegg, Apr 7, 2013

schmegg wrote:

And quite honestly, we were talking about FF and crop comparisons. Looking at those images, I'd say the phone has actually done remarkably well TBH!

At what crop factor your statement becomes incorrect and why?

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