I understood the mpix score to be the total amount of resolution the lens is capable of resolving, which I got from the dxomark faq. Surely, however, that is wrong, since the purported best lens on m43 is the 75mm, which gets an mpix score of 11mpix. Surely this is not saying that it can only resolve 11mpix?
-
Welcome to the new forums! Please read this first. For known issues we are working to resolve, click here.
DXO Mark's rating of m43 lenses
- Thread starter zenpmd
- Start date
Cipher
Senior Member
Methinks. If you put the 75mm on a 12MP body it should score lower than if it was put on a 16MP body.
Great Bustard
Forum Pro
- Messages
- 45,961
- Solutions
- 17
- Reaction score
- 34,046
No. The test is how well the lens performed on the particular camera it was tested on, but how they compute their PMP (perceptual megapixel) scores is of dubious value, as it tries to give a single metric across all apertures and across the entire image circle.
Not particularly useful, methinks.
I'm pretty sure that the PMP metric will not be higher than the pixel count of the sensor, except when rounding for a very sharp lens (e.g. a PMP rating of 13 on a 12.8 MP sensor).
Put more pixels behind any lens, and you will resolve more detail, for a given relative AA filter. For example, the 75 / 1.8 will get a higher PMP rating when mounted in front of a 16 MP sensor than a 12 MP sensor.
Cipher
Senior Member
I don't think you can. Again, the pixel density affects the sharpness rating. You should only compare lenses on cameras using the same sensor. So if you're wondering if the Olympus 45mm f1.8 on the OMD is sharper than the Panasonic Leica 45mm f2.8 on the OMD, it would make more sense.
Great Bustard
Forum Pro
- Messages
- 45,961
- Solutions
- 17
- Reaction score
- 34,046
What do you want to know, exactly? If the 75 / 1.8 or 135 / 2L is sharper, or which resolves more detail on the camera they are used on?
MAubrey
Senior Member
FYI: You can still look at resolution info for individual apertures and different locations across the frame.
Aleo Veuliah
Forum Pro
Why not Nikon Pro glass, Nikon does better wide and ultra wide lenses. On long focal lengths it is easier to make good lenses.
I am kidding a bit, Micro 4/3 lenses choices is great and with good IQ.
MatsP
Senior Member
If you take a look at SLRGear they indicate that the 45/1,8 is sharper than the EF 135/2 L. No doubt that both are extremely sharp with no edge blur at all between f/5,6 and 8. They are tested on EPL1 and 5D respectively, both 12 MP. The 135 costs four times the 45 and weighs six times more.
I guess that both lenses are capable to resolve a lot more than 12 MP. Anyway, 12 MP is a lot and more than enough for very big prints.
Franka T.L.
Veteran Member
figure ( as a piece of datum ) vs that of info. The 11Mpix is a relative measurement , its a piece of info that you can relay to comparable datum from the same set of test ( say against the other M4/3 lens DxO tested
Of course that piece of info is not really the real technical measurement of how the lens can do, that would be the real technical measurment of resolution, and that measurment BTW, is never measured in Mpix. in fact its broken down to a set of measurements. Technically speaking its never a single measurement
Of course that piece of info is not really the real technical measurement of how the lens can do, that would be the real technical measurment of resolution, and that measurment BTW, is never measured in Mpix. in fact its broken down to a set of measurements. Technically speaking its never a single measurement
slimandy
Forum Pro
KenBalbari
Forum Enthusiast
Well would you also buy a FF camera, or an APS-C?
If you look at the Canon 135mm f2 L for example, the highest score it achieved was 14 P-Mpix on the 5D Mark II and on the 1DS Mark III, both FF 21 MP models. But it only scored 11 P-MPix on the 550D and 10 P-MPix on the 7D, both APS-C 18 MP models.
So keep in mind, P-MPix are telling you what resolution would of a perfect lens (and sensor) of the same sharpness. In other words, to get 16 P-MPix from a 16MP camera, it would have to be perfect. It never is. A score of 9MP on a 12MP camera (the 75 1.8 on the E-PL2 for example) is actually pretty impressive.
To be fair though, the 135mm f2 wasn't one of the top Canon performers, either. Here's a few of those, showing how they scored on the 5D MIII compared to the 7D:
5DIII 7D
22 14 Canon EF 300 f2.8L IS II USM
21 12 Canon EF 70-200 f2.8L IS USM
20 11 Sigma 85 F1.4 EX DG HSM
19 11 Canon 24 f2.8 IS USM
So it may be possible with the very best performers on a 35mm size camera to get near to double the area resolution, which means about 40% better in linear resolution (such as lp/mm). But the differences from the best performers on m4/3 and APS-C cameras are very small.
Unfortunately, DxO doesn't have results for the latest cameras from either, including the OM-D and GH3.
Last edited:
Lost in Time
Well-known member
- Messages
- 207
- Reaction score
- 32
I don't think that it makes sense to compare between different camera systems.
The actual 'sharpness' you will perceive is going to depend on many things, such as depth of field, post processing and even motion blur (DXO's images are taken with rock solid tripods and presumably all possible anti-shock/mirror slap precautions - how often do you do this?).
The single perceptual MP score also hides a lot of things. Portrait lenses like the 135L are designed for excellent sharpness in the centre, colour rendition and excellent bokeh. They are not necessarily designed for edge-to-edge sharpness as in the main application the edges are much less important to the overall image. It is a fast prime intended for portraits, not a general purpose do-everything lens.
As with all these things, summarising as a single number is usually over simplifying. I find the photozone.de lens reviews more useful, as they don't condense the results to a single score and they usually give helpful images to compare.
The actual 'sharpness' you will perceive is going to depend on many things, such as depth of field, post processing and even motion blur (DXO's images are taken with rock solid tripods and presumably all possible anti-shock/mirror slap precautions - how often do you do this?).
The single perceptual MP score also hides a lot of things. Portrait lenses like the 135L are designed for excellent sharpness in the centre, colour rendition and excellent bokeh. They are not necessarily designed for edge-to-edge sharpness as in the main application the edges are much less important to the overall image. It is a fast prime intended for portraits, not a general purpose do-everything lens.
As with all these things, summarising as a single number is usually over simplifying. I find the photozone.de lens reviews more useful, as they don't condense the results to a single score and they usually give helpful images to compare.
Doesnt this mean then it always makes more sense to have more mpix in the sensor?
If I put a moderate lens in a 36mpix d800 - yes, I wont be getting the best from it, but I could get more than an exceptional lens on something like a 12mpi d700?
So lets say a moderat lens gets 50 percent of the mpix on the d800, I get 18mpix, on a d700 it will get only 6mpix?
If I put a moderate lens in a 36mpix d800 - yes, I wont be getting the best from it, but I could get more than an exceptional lens on something like a 12mpi d700?
So lets say a moderat lens gets 50 percent of the mpix on the d800, I get 18mpix, on a d700 it will get only 6mpix?
L glass will cost you at least 50% extra usually...
slimandy
Forum Pro
That depends on how big you are printing. Do you need 36m pixels? I have seen very detailed images from 4m pixels. Other factors come into play. It's not all about resolution.
Lost in Time
Well-known member
- Messages
- 207
- Reaction score
- 32
Sometimes. However, going to ever more pixels may justy mean that you images are soft due to diffraction, camera shake and less-than-perfect optics.
I think that the days of every new generation of device doubling resolution and/or DR are coming to an end, as both sensors and optics are now getting pretty close to their physical limits. For example, the OM-D starts to show diffraction softening not much after f4, and the more pixels that you pack in the wider the aperture you need to make use of them.
I have to say that I haven't really felt sharpness was an issue with any u4/3 or FF lens. I would, however, like more lenses with weather sealing and more with speciality features (tilt-shift, faster-thanf1.4-AF-primes for depth of field control, etc).
KenBalbari
Forum Enthusiast
Yes, you will get more resolution from more megapixels, but the gains aren't as linear as that. It seems efficiency gets less as you try to squeeze more on there.
So in reality it's more like a moderate lens get 16 P-MPix on the d800 and 9 P-MPix on the D700 (those are actual results from the 50mm f/1.4G, and 35mm f/2D, and probably a number of others). And the very best performing lenses on the d800 are still only at 22 or 23 P-MPix, not that different from the best on the 5D Mark III.
And small sensor compacts especially trying to squeeze 14-16 MP on the smaller sensor aren't giving you near that, mainly because they are blurring detail from needing noise reduction even at low ISO.
Last edited:
Keyboard shortcuts
- f
- Forum