Reading resolution charts comparing MFT lenses to FX lenses

Started Mar 29, 2013 | Questions
OP Prairie Pal Senior Member • Posts: 2,665
Re: Reading resolution charts comparing MFT lenses to FX lenses

Anders W wrote:

Prairie Pal wrote:

I'm at photozone review website browsing through lenses for both FX and MFT.  I see that the highest resolving FX lenses can be near the 4000 lw/ph range.  The better MFT lenses rarely even get to 2300.  Is the difference between the 2 types of lenses relative?

Not sure what you mean by relative but I certainly wouldn't call the difference real.

I think I was asking whether a "conversion formula" could be applied for comparing the relative ranking of a specific MFT lens within its peers to the ranking of a specific FX (or DX for that matter) lens within its peers.  Furthermore, I would like to understand if the performance of a number FX/DX legacy glass on thier respective sensors maintain their ranking when adapted to MFT, AND whether they outperform the current MFT lens offerings.

The discussions so far in this thread are starting to clear my understanding a bit.  A bit.

I'm currently very impressed with two unlikely Nikon lenses on my EM-5; Nikon DX 35/f1.8 & an old E 135/f2.8

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Dr_Jon Veteran Member • Posts: 5,516
Re: Reading resolution charts comparing MFT lenses to FX lenses

Anders W wrote:

You are obviously wrong about that.

Yup, that's why it disappeared almost immediately after I wrote it, although his 24-70 lens tests did really look that way when I started looking at them. Shouldn't write as I think.

I really like my GH3 and especially the 35-100 zoom, but it is significantly noisier than my 5DmkII and somewhat less sharp as a system. I don't think m43 is the one true camera system that some people do, but it does have its place due to the size/weight issues (alas not with high quality long lenses just yet, but hopefully someday). Like I said, happy GH3 owner, but if you want a consumer DSLR right now and size isn't the key factor the Nikon D5100 with the kit zoom for £375 is just knocking it out of the park (not a fan-boy of any system really, I'll recommend anything I think is good).

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Dr_Jon Veteran Member • Posts: 5,516
Re: Ideally...

Depends if you need to crop to zoom, if not I think any current DSLR/Mirrorless will do well.

I shot a duck with a cool cylon-like bright red eye in Regents Park the other day. I had the GH3 with the 12-35 on it. The duck just wouldn't swim close to me so I shot it at 35mm and thought I'll get away with it as I'll have enough pixels over it for Facebook. However it was ISO800 and the noise-reduction just killed the detail in the JPEG. The raw is better but not great. My 5DmkII does this stuff really well, but you have to carry all the extra weight.

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Dr_Jon Veteran Member • Posts: 5,516
Re: Reading resolution charts comparing MFT lenses to FX lenses

Err, no, I think I must disagree. 50lp/mm over a 10mm sensor is 500lp of detail which most sensors would easily resolve. 80lp/mm over a 3mm sensor is only 240lp (in the picture height) so lower resolution even if you have a sensor that could resolve 1000lp/mm. It's lp/mm and the mm over which it manages it that gives sharpness, regardless of the sensor (as long as it's in the ball park, no 2x2 pixel systems need apply).

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Anders W Forum Pro • Posts: 21,468
Re: Ideally...

Great Bustard wrote:

Anders W wrote:

Great Bustard wrote:

However, here's what would be awesome:  take the make a bench that mounts the lens in front of the highest pixel density sensor out there.  Take some photos from various portions of the image circle, and use the same RAW converter with the exact same settings each time.  Now you're really testing the lens, and not the system.

Yes. I have thought of it. If all lenses were manual, it would probably have been done already. But you can't even focus or stop down an MFT AF lens without the right body electronics. And if it's an OIS lens, the OIS lens group could be anywhere without power.

I did not know that!

Isn't it the same with regard to aperture control as well IS on Canon EF? And with regard to IS on any system?

Of course, this now opens a huge can o' worms, since the lenses for smaller sensor systems will, on average, resolve better than lenses for larger sensor systems, and we'll have the ignorant masses chanting "lw/ph = lw/ph" to go along with "f/2 = f/2", and any attempts to educate will be met with "entertainment".

But, now that I think about it, I'm good with that. 

Not with you and me around to do the education.

Maybe not with you, but you know that "entertainment" always finds me and I always find "entertainment".

As you know, I am open to the idea that it is fair to compare an MFT X mm lens at f/2 with an FF 2X mm lens at f/4, since that's the point where they are equivalent in terms of DoF, diffraction and light accumulation (and thus photon noise so that there would no longer be any difference with regard to the possibility to sharpen in PP). And I much prefer such comparisons to those we can make on the basis of Photozone results.

Except that often the larger sensor system is simply using a longer shutter speed for the same DOF.

And what would prevent the MFT user from using the same longer shutter speed and thus getting the same amount of light on the sensor nevertheless?

Still, I had better add that such comparisons are no panacea either. One reason is that we ignore the complicated read-noise issue when we just go by the general two-stop difference rule. Another is that it is not reasonable to expect an MFT X mm f/2 lens to do just as well wide open as an FF 2X mm f/4 lens or to expect the two to have similar price tags.

Indeed.

There are physical reasons why the MFT lens faces a tougher job in such a comparison, and we should take that fact into account when we look at how well they accomplish. Naturally, we should also take it into account when choosing between systems. If you chose to go with MFT without realizing that the MFT X mm f/2 lens would probably cost more and perform worse wide open than the corresponding FF 2X mm f/4 lens (if it were available ), it simply means you haven't done your homework properly.

To be perfectly honest, I think we are well, well, well past the point where differences in resolution matter for the vast majority.  That is, if you took a pic of a scene with the kit lens and the 12-35 / 2.8, printed them even at 16x24 inches, put them both for sale, they'd sell for the same price and in the same amount.  Well, maybe you'll sell 53 of the pics shot with the 12-35 and 47 pics shot with the kit lens, but you get what I'm saying.

I'm just coming to the opinion that any IQ differential between lenses and systems is simply unimportant for the vast majority in the vast majority of situations, and it's only for the extremes that it matters.  And by "extremes", I mean the very extremes.

Well, that may be true for the majority but what about me?

Seriously, though, I can agree up to a point. The fact that good MFT primes do sufficiently well for my resolution standards at apertures about f/2 (and significantly better than anything but the newest FF lenses can manage at the same f-stop) although they don't do quite as well as an FF combo at f/4 was an important reason for me to dare take the plunge into the MFT world. Of course, given the circumstances in terms of DoF and photon noise, I would want/need to use an aperture as wide as f/2 on MFT far more often than an FF user would want to use the same f-stop, everything else equal. So fast primes that perform sufficiently well already wide open or thereabout become critical.

On a more general note, though, I am curious about whether what we can actually see in terms of resolution with current display or printing technology (and no peeping) will hold true in the future. What would the situation be like if we had displays of the same size but with 16 MP rather than 2 MP resolution. Would we still be unable to see much of a difference?

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richarddd
richarddd Veteran Member • Posts: 3,101
Re: Ideally...

Great Bustard wrote:

I'm just coming to the opinion that any IQ differential between lenses and systems is simply unimportant for the vast majority in the vast majority of situations, and it's only for the extremes that it matters.  And by "extremes", I mean the very extremes.

Vast majority likely understates it.

I'd bet most people form an impression of a photograph immediately, based on subject, composition and general coloration. Angle of view is very noticeable. Camera shake, motion blur, general DOF are likely noticeable. lp/ph is way down in significance   Considerations such as noise are even less important - as they say, if your viewers are complaining about noise, your photos have much more fundamental problems than noise.

What do you think people notice?

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Ulric Veteran Member • Posts: 4,534
Re: Reading resolution charts comparing MFT lenses to FX lenses

KenBalbari wrote:

As far as I know, no one currently makes an interchangeable sensor camera.  Though I'd like to see someone try it.

There are exchangeable digital backs for MF cameras.

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richarddd
richarddd Veteran Member • Posts: 3,101
Re: Ideally...

Anders W wrote:

On a more general note, though, I am curious about whether what we can actually see in terms of resolution with current display or printing technology (and no peeping) will hold true in the future. What would the situation be like if we had displays of the same size but with 16 MP rather than 2 MP resolution. Would we still be unable to see much of a difference?

TV and video have increased in resolution over time. When you were watching TV as a child, did you complain about low resolution?  It's amusing to read old articles about the amazing fidelity of wax cylinders.

It's easier to notice differences when comparing side by side or when there are major differences from what you are used to.

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KenBalbari Regular Member • Posts: 276
Re: Reading resolution charts comparing MFT lenses to FX lenses

Anders W wrote:

If the pixel count of the sensors is the same, and the impact of the AA filter comparable, they have the same resolution irrespective of sensor size.

Generally, in theory, if there is no limit to available light. In practice though, it seems noise really is what often ends up limiting resolution.

There are plenty of 16MP cameras for example using a 1/2.5" sensor.  Even in tests with controlled studio lighting, they tend to not resolve as well as larger sensor 16MP models. DPR hasn't reviewed that many of these, but if you look at the ones they have, you invariable see in the comments, for example for the Nikon S9300 :


  • Noisy and soft photos have noticeable detail loss, even at base ISO of 125

and for the Sony HX20V :


  • Lots of detail smudging, even at ISO 100

or the TX10 :


With the TX10, there is definitely evidence of strong noise reduction at all ISO sensitivities with images even at ISO 100 exhibiting a slightly 'plastic' look when examined closely.


Of course, the reason these cameras are smudging detail even at low ISO is because noise is a problem for them even at low ISO.  If what you want to compare is different cameras, sensors, or formats, technically it's generally noise which is the limiting factor for resolution.

This can also be seen in DxO's "perceptual megapixels" measure.  It is apparent there that sensor size usually has more impact on resolution than the actual number of megapixels, so long as you are comparing sensors of near the same generation.  On the 10MP Nikon V1, for example, the four Nikon "one" system lenses all test at from 3-6 P-MPix.  Meanwhile, even on the much older Olympus E410, E510, and E3, also at 10MP, the 14-42 kit lens delivered 5 P-MPix.  So the modern Nikon "one" is barely matching the resolution available from a 4/3 sensor from 2007. But on modern m4/3 bodies with 12MP and 16MP, some similar 14-42 kit lenses are still only delivering 5 P-MPix.  Comparing other lenses going from older Panasonic 12MP bodies to newer 16MP bodies, tested with the same lenses, there are small gains.  The same lens might go from 7 to 8, or 8 to 9 P-MPix.

There seems to me to be more gain in moving to an equally current full frame sensor, even with no increase in megapixels.  The Nikon D4 for example, also with 16MP, has numerous lenses delivering 13-14 P-MPix, when the very best lenses on the GH2 or F1X are at 9-10 P-MPix.

So it seems to me megapixels and sensor size both matter.  But for the OP's original question, are the FX lenses generally sharper.  The answer is no.   The sensor is larger.  And larger sensors are generally sharper.  It's possible for sensor design decisions to trade resolution for other advantages (dynamic range, color depth, etc.) but it would take some pretty unusual decisions (or maybe using technology that is 5-years older) to produce a full frame sensor that doesn't provide higher resolution than a 4/3 sensor.

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KenBalbari Regular Member • Posts: 276
Re: Reading resolution charts comparing MFT lenses to FX lenses

Dr_Jon wrote:

Err, no, I think I must disagree. 50lp/mm over a 10mm sensor is 500lp of detail which most sensors would easily resolve. 80lp/mm over a 3mm sensor is only 240lp (in the picture height) so lower resolution even if you have a sensor that could resolve 1000lp/mm. It's lp/mm and the mm over which it manages it that gives sharpness, regardless of the sensor (as long as it's in the ball park, no 2x2 pixel systems need apply).

Actually, I think you are agreeing.  That's pretty much exactly what I was saying.

My only point with lp/mm is that it is useful for the original posters question.  As I made clear, this is ignoring sensor performance and final image quality.  That's a pretty significant qualification, and those are things you obviously wouldn't ignore if comparing cameras or systems.

If you look above though, where Prairie Pal clarifies his question, he says:


"I think I was asking whether a "conversion formula" could be applied for comparing the relative ranking of a specific MFT lens within its peers to the ranking of a specific FX (or DX for that matter) lens within its peers.  Furthermore, I would like to understand if the performance of a number FX/DX legacy glass on thier respective sensors maintain their ranking when adapted to MFT, AND whether they outperform the current MFT lens offerings."


This is where I think lp/mm can come in handy.  Though I think it's really only useful when you have a tester who tests various lenses, from different systems, all on the same test bench.  Trying to convert between tests on different cameras isn't going to be as reliable.  Worth knowing more just to understand what is being measured.

For the photozone tests, for example, if you look at the Nikon 35mm f/1.4 G lens, they actually tested that on both a D3x (full frame) and  D7000 (APS-C).  That might help to see how the MTF results "translate" between two different formats.    On the D3X, the top of the chart, which they consider roughly the maximum possible MTF for the D3X, is 4000 lw/ph, and "excellent" is from 3450-4000.  On the D7000, the maximum on their chart is 2900 lw/ph, and "excellent" is from 2500-2900.  The lens is generally "excellent" in the center, and "very good" at the edges from f2.8 down.

As to how it would perform on the OM-D, I'd say very similarly to the D7000, since that camera test very similarly in overall resolution. Per DP Review resolution tests:

"Whereas in the JPEG files, the D7000 cannot accurately describe the 9 lines on our test chart much beyond 2600LPH (roughly), the RAW file still shows all nine lines distinctly at 2600LPH, and they only begin to merge at around 2800LPH." ( link )

"At first glance the E-M5's JPEGs give the impression of being able to render 2800 lines per picture height. This is essentially impossible and closer examination shows the last point at which it clearly differentiates between the lines is actually nearer 2600 (which is what you'd expect of a sensor of this resolution)."  ( link )

One thing to note is that the two scales (DPR and PZ) here are not comparable, as DP review is not using an  MTF50 definition of resolution.  Also, the DPR test is also influenced by the lenses they use, though they do try to pick one of the sharpest available for a camera, in order to get close to the maximum for the sensor.

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MAubrey
MAubrey Senior Member • Posts: 1,600
Re: Reading resolution charts comparing MFT lenses to FX lenses

Dr_Jon wrote:

I really like my GH3 and especially the 35-100 zoom, but it is significantly noisier than my 5DmkII and somewhat less sharp as a system.

I would hope so, considering that the SNR of the 5Dii is two stops better than the OM-D.

I don't think m43 is the one true camera system that some people do...

If you're referring to noise, then that really depends on your perspective and what you view as "good enough." The most recent crop of μ43 sensors are equal to or better than the Canon 5D classic and I don't remember anyone complaining about the quality of that camera when it came out (I never saw sufficient motivation to move to a mk2...maybe when my shutter wears out). That's an achievement that's nothing to scoff at. And in another few years, μ43 will be on par with the sensor quality of the current crop of 35mm sensors. Again, its all a question of what's "good enough."

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--Mike

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MAubrey
MAubrey Senior Member • Posts: 1,600
Re: Reading resolution charts comparing MFT lenses to FX lenses

Prairie Pal wrote:

Anders W wrote:

Prairie Pal wrote:

I'm at photozone review website browsing through lenses for both FX and MFT.  I see that the highest resolving FX lenses can be near the 4000 lw/ph range.  The better MFT lenses rarely even get to 2300.  Is the difference between the 2 types of lenses relative?

Not sure what you mean by relative but I certainly wouldn't call the difference real.

I think I was asking whether a "conversion formula" could be applied for comparing the relative ranking of a specific MFT lens within its peers to the ranking of a specific FX (or DX for that matter) lens within its peers.  Furthermore, I would like to understand if the performance of a number FX/DX legacy glass on thier respective sensors maintain their ranking when adapted to MFT, AND whether they outperform the current MFT lens offerings.

The discussions so far in this thread are starting to clear my understanding a bit.  A bit.

I'm currently very impressed with two unlikely Nikon lenses on my EM-5; Nikon DX 35/f1.8 & an old E 135/f2.8

Well...in the simplest terms, your 35mm f/1.8 and 135mm f/2.8 is likely to be be getting more lp/mm on the μ43 than they would on a 35mm format sensor (because the μ43 sensor is denser), but fewer lp/ph (because resolution doesn't scale linearly with pixel density).

You can see this analogously if you compare the resolution numbers of the Nikon D800's 36MP compared to the D700's 12MP:

http://www.lensrentals.com/blog/2012/03/d-resolution-tests

The D800 has three times the number of pixels, but it doesn't get three times the resolution because resolution doesn't scale linearly with pixel density.

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tjdean01 Senior Member • Posts: 2,255
Re: Ideally...

To be perfectly honest, I think we are well, well, well past the point where differences in resolution matter for the vast majority.  That is, if you took a pic of a scene with the kit lens and the 12-35 / 2.8, printed them even at 16x24 inches, put them both for sale, they'd sell for the same price and in the same amount.  Well, maybe you'll sell 53 of the pics shot with the 12-35 and 47 pics shot with the kit lens, but you get what I'm saying.

I'm just coming to the opinion that any IQ differential between lenses and systems is simply unimportant for the vast majority in the vast majority of situations, and it's only for the extremes that it matters.  And by "extremes", I mean the very extremes.

There's one thing a lot of people fail to consider on this forum, while shopping, and in general, life.  It's that people have opinions that cannot be changed by others.  I'm as guilty as anyone.  I call guys dumb for spending $1000s for rims on their car; and in many cases I'm sure I'm right, but some people have valid reasons for things.  So what purpose does a purple PM1 with the lowly 17mm f2.8 lens serve?  A great starter cameras coaxing your girlfriend into photography, no?

I've seen a lot on this forum talking about how the sharpness of an image is not important.  Says who?  You?  (Not you personally I'm just saying in general.)  How can anyone tell anyone else that sharpness isn't important?  What if I want to take a landscape photo and view it at 100% and drag it around my computer screen and look at how sharp my new lens is?  Is there anything wrong with that?  It's no worse than sitting around watching a TV show.

Either way, I like sharpness.  The sharper the better.  It's in-camera sharpening that looks sharp to my eye but doesn't result in real resolution and I can't see that it's been over-sharpened (I can usually tell if it's oversharpened, however), then guess what?  It'll be my favorite!

tjdean01 Senior Member • Posts: 2,255
Re: Ideally...
1

richarddd wrote:

Anders W wrote:

On a more general note, though, I am curious about whether what we can actually see in terms of resolution with current display or printing technology (and no peeping) will hold true in the future. What would the situation be like if we had displays of the same size but with 16 MP rather than 2 MP resolution. Would we still be unable to see much of a difference?

TV and video have increased in resolution over time. When you were watching TV as a child, did you complain about low resolution?  It's amusing to read old articles about the amazing fidelity of wax cylinders.

It's easier to notice differences when comparing side by side or when there are major differences from what you are used to.

This made me think about the differences of 720 vs 1080 pixel TVs.  The whole world wants 1080 because that's what their brother-in-law told them to get (their no-nothing brother-in-law also thinks that TVs have LED screens and that plasma TVs will break in a year).  In truth, however, when people come in the store to look at TVs their eyes take them to 720 (hard to notice a lower pixel height at 10 feet) plasma (better color) TVs.  They are all interested in buying especially when they see it's a 50" TV for $500 and in reality this is a very, VERY good deal.  But they ended up leaving with a crappy Samsung 46" LCD TV they paid $900 for.  Why?  They heard to buy Samsung, not LG.  They heard that plasma is bad LED is good (LED doesn't exist, it's LCD, but the world has nearly been convinced).  And they heard they need 1080.

This is kind of a continuation of my other post in the thread, where others were talking about how resolution doesn't matter in prints, etc.  I don't care about resolution either, but I like really sharp pictures at 100%.  OMD at 8 MP JPEG?  Sure, as long as it's sharp!

Back to the TVs, however.  I just wanted to note that people's thoughts can overpower what they really like.  You want to ask that cute girl on a date until you realize that she shoots with a Sony NEX, for example

tjdean01 Senior Member • Posts: 2,255
Re: Reading resolution charts comparing MFT lenses to FX lenses

MAubrey wrote:

Dr_Jon wrote:

I really like my GH3 and especially the 35-100 zoom, but it is significantly noisier than my 5DmkII and somewhat less sharp as a system.

I would hope so, considering that the SNR of the 5Dii is two stops better than the OM-D.

I don't think m43 is the one true camera system that some people do...

If you're referring to noise, then that really depends on your perspective and what you view as "good enough." The most recent crop of μ43 sensors are equal to or better than the Canon 5D classic and I don't remember anyone complaining about the quality of that camera when it came out (I never saw sufficient motivation to move to a mk2...maybe when my shutter wears out). That's an achievement that's nothing to scoff at. And in another few years, μ43 will be on par with the sensor quality of the current crop of 35mm sensors. Again, its all a question of what's "good enough."

If that's the case why did it take them so darn long to make something small that even holds a flame to the 2006 Fuji F30?  Good sensor at 6MP and sharp lens.  I know I'm mentioning the whole camera and not just the sensor as you said, but the sure, the Canon s100 was better and maybe the s90 but neither of them convinced me to buy meaning they weren't even that much better.  Nikon P330 looks like it might though!

Dr_Jon Veteran Member • Posts: 5,516
Re: Reading resolution charts comparing MFT lenses to FX lenses

Thanks for that considered reply. It's tricky as the smaller sensors have advantages with over-sized lenses (using the "best bit" of the lens and the corners would have less of an angle for the incoming light if using the same flange distance). As to just how a lens scales from FF to crop it seems complicated as you'd really like the smaller sensor to have the same pixel count and, relatively, the same strength AA filter.

I think perhaps we misunderstood each other (sorry for my bit in that if so). I'm okay with lp/mm if not compared directly but the sensor/pixel sizes and other factors are allowed for. Perhaps my somewhat ongoing disagreement with Anders over the absolute quality of m43 vs. FF coloured my reading of your comments (plus I was a bit exhausted yesterday).

Anyway, my original reading of the OP's question was whether FF lenses on FF cameras will produce sharper pictures than m43 lenses on m43 cameras and I think they will. I think that's partly down to the rest of the image processing system and partly that Canon and Nikon do make some very sharp glass. Other opinions are available... lots of them... Whether sharp FF lenses will be better on m43 cameras than sharp m43 lenses is a more complicated one.

Comparing MTF curves is also tricky, as manufacturers don't seem keen on producing them in comparable ways. Looking at the curves for the Olympus 75/1.8, perhaps the sharpest m43 lens, at http://www.personal-view.com/talks/discussion/3323/75mm-f1.8-olympus-lens-topic/p1 then comparing with the super-sharp Canon 300/2.8 II, http://www.usa.canon.com/cusa/consumer/products/cameras/ef_lens_lineup/ef_300mm_f_2_8l_is_ii_usm (look at the lowest one, the others are with extenders), would suggest the Canon is miles better (I suspect it is somewhat better, my 300/2.8 IS is stunning and the mkII curves are a step up from it) but I'm not sure it's useful as the data isn't produced the same way.

Thinking about using lp/mm for comparison is complicated as FF lenses are usually compared using much larger pixel size cameras, limiting the lp/mm achieveable. It's perhaps not so hard to work out the FF/FF vs. m43/m43 relative sharpnesses, but tricky to work out how much better an FF lens would be on a higher resolution/mm sensor (which m43 cameras must be as long as they have higher pixel densities).

My 5DmkII has 3755 vertical pixels and the GH3 3456 pixels, that's only 8% less which isn't much. If I go to LensTip and use their lp/mm figures my 35-100 lens nearly gets to 80lp/mm at the centre at 100mm and f5.6, it's a lot less everywhere else. My Canon equivalent is above 40 lp/mm at all focal lengths and all over the frame from f2.8-f8.0. You'd think then the Canon system was sharper as it seems to be making better use of the Camera's resolution.

However unfortunately they are using a 12MP m43 sensor (ph=3024, plus Olympus AA filter/processing, 224 pixels/mm) vs a 20MP (almost exactly identical to my 5DmkII) sensor for Canon so they aren't that comparable. You then need to estimate how much of a limiting effect the camera (etc.) has on the result. Fun... err, not.

The super-sharp 75/1.8 hits 82 lp/mm on the same camera but is mostly some way below that, so perhaps the camera isn't the absolute limiting factor (if so I'd expect a very sharp lens to have more of a slightly rounded plateau). Perhaps the Camera the use is more just taking the edge off the results.

Looking at their results for the Canon lens (300mm f2.8 II) that peaks at about 47 lp/mm, suggesting that might be the limit of what the total test system can resolve in their tests (the 70-200 gets to a bit of a plateau at 48-ish).

However what it doesn't say is how much the Canon lens has left in hand, as the testing camera's pixels are about half the height of the GH3 ones so it can't say if the lens could resolve further unless someone adapts it to a GH3 and measures it. Also doesn't help with how much the GH3 would improve things over the 12MP camera. Hence hard to say what the Canon would do on a m43 camera.

Roger's tests (http://www.lensrentals.com/blog/2013/01/a-24-70mm-system-comparison) show, as you would expect, that more camera/sensor resolution = better overall resolution, but nothing like linearly, again as you'd expect. I'm better at bandwidth maths on analogue systems (3dB points, etc.), but cameras throw in Nyquist and other annoyances and who knows how the test software interpolates the results.

On the above basis I think (personally) it is reasonable to say (using the above lenses) a pic on my Canon will appear sharper (at the same visual size) than a pic from my GH3 as there is more sharpness over the picture height (and believing Imatest on the merits of MTF50 as a measure of visual sharpness). That's using the 75mm result to suggest the GH3 won't add more than say 3-4% to the numbers (14% extra vertical pixels, extra resolution probably less so with educated guessing on AA filter strengths, but if the lens is the more limiting factor at 12MP then we will see well under half of that increase).

One thing I did do a while back was compare lens resolution on my 5DmkII vs a 7D to see how economical it was to use a 7D to give extra reach with a lens rather than buying the next big white lens up. A 7D has 1.5x the linear pixel density of the 5DmkII but IIRC the improvement in sharpness was more 20--30% than 50%, suggesting it isn't the way to go.

Also I'm not going too far with the analysis as the extra per-pixel noise from the m43 sensor as  would also limit the resolution as the pixel density went up, the larger sensor in vaguely comparable technology will always be ahead there.

Wrote that a bit quickly as have to go out, hope there is some sense in it...

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Dr_Jon Veteran Member • Posts: 5,516
Re: Reading resolution charts comparing MFT lenses to FX lenses

Also small sensors could be diffraction limited with the lens wide-open, which will knock a little off the result (or a lot with teeny sensors).

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Dr_Jon Veteran Member • Posts: 5,516
Re: Reading resolution charts comparing MFT lenses to FX lenses

The D800 has 73% more vertical pixel density than the D700. Since resolution is more a linear thing I think that is the more relevant number.

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MAubrey
MAubrey Senior Member • Posts: 1,600
Re: Reading resolution charts comparing MFT lenses to FX lenses

Sure, if you want to do that, that's fine. Either way the efficiency of a lens still isn't going to scale linearly with the increase--the increase of lp/ph in the chart is 46.667%.

It's also documented here:

Which lenses for your Nikon D800?

I was just trying to give the OP a useful analogy.

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MAubrey
MAubrey Senior Member • Posts: 1,600
Re: Reading resolution charts comparing MFT lenses to FX lenses

tjdean01 wrote:

MAubrey wrote:

Dr_Jon wrote:

I really like my GH3 and especially the 35-100 zoom, but it is significantly noisier than my 5DmkII and somewhat less sharp as a system.

I would hope so, considering that the SNR of the 5Dii is two stops better than the OM-D.

I don't think m43 is the one true camera system that some people do...

If you're referring to noise, then that really depends on your perspective and what you view as "good enough." The most recent crop of μ43 sensors are equal to or better than the Canon 5D classic and I don't remember anyone complaining about the quality of that camera when it came out (I never saw sufficient motivation to move to a mk2...maybe when my shutter wears out). That's an achievement that's nothing to scoff at. And in another few years, μ43 will be on par with the sensor quality of the current crop of 35mm sensors. Again, its all a question of what's "good enough."

If that's the case why did it take them so darn long to make something small that even holds a flame to the 2006 Fuji F30?  Good sensor at 6MP and sharp lens.  I know I'm mentioning the whole camera and not just the sensor as you said, but the sure, the Canon s100 was better and maybe the s90 but neither of them convinced me to buy meaning they weren't even that much better.  Nikon P330 looks like it might though!

I'm not entirely sure I know what you're talking about.

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