16MP sensor improvements?

Started Apr 24, 2013 | Questions thread
Najinsky Veteran Member • Posts: 5,739
Coke bottles and flatlines

The idea behind the game was to see if we could get the discussion around images rather than just the numbers. But perhaps many people were uncomfortable offering an opinion without the safteynet of the numbers to support them. The numbers will cripple us!

So as I already did all the work for the tests I wanted to show, I'll take a different approach and let you simply have the tests and the numbers.

But before I do that, I need to get this preamble out of the way.

While the numbers are cool in allowing us to relate like things to each other, they don't really provide any context for their impact on the utility of the images; is it a wall poster, a calendar, a centrefold, a slideshow or just a web thumbnail.

So in this post I'll provide some visuals of the numbers, and in the next post I'll add some test shots to help show the actual impact of all these numbers.

I'll start with this visual of DPRs MTF chart for the Olympus M.ZD9-18 @ 9mm:

First we need to give some context to these numbers. Here's what works for me. Blue is Excellent. Green is Good. The Yellow of the 750 line is the borderline. That's the line we don't want to fall below because that way lies Red-uced Utility and then down to Purple, for Pack up and go. Here be the coke bottles.

At these wider Apertures, around F4-F5.6, is where most M.4/3 lenses like to show their true colours. They show off just how sharp they can be, and how well they can keep it up across the frame.

There's, kind of, three short lines hiding in there, one for centre, one for corners, and the other links those two. This gives the lens performance a shape on the chart.

As we stop down further, diffraction slowly kicks in plays the role of the leveller.

At F8 the lens has lost a little resolution at the centre but it's still holding it's shape.

By F16 we've lost a lot of the shape and the corners have dropped below our self imposed borderline. With a center focussed subject we may still be just ok, it depends on the intended utility of the image; on where we draw the boderline.

By F22 we've lost nearly all our shape, over half the image has dropped clearly below the borderline and we're well on the way to flatlining in the red.

Most lenses will follow this same pattern, and this is what Joe referred to in his response to the original round 1 image.

However, there is can still be significant variance in the performance of different lenses. Here's the chart for Panasonic's wide zoom, the 7-14/4 @ 9mm.

At F/16 it's putting in a noticeably stronger performance than the Olympus, with a good centre and nearly all the image above the borderline.

But by F/22 it could essentially be the same lens as the Olympus, except for the telltale CA differences.

And here's the very beautiful PanLeica 45/2.8:

At F16 it's putting in a good performance with all of the image comfortably above the line and pretty even across the whole frame.

And even by F22 it's still putting up a valiant effort to hold the line.

Obviously, people are different and have different requirements and expectations, and some will draw their own lines below which they've decided they shouldn't fall.

But in general, I feel the above clearly shows that even at F/16, the lens optics are still having a significant influence on the resolution, and while the effects of diffraction are clear, the lens has not yet been overpowered. In the case of the PL45, it is still putting up a fight at F/22.

Obviously, the above were produced by DPR using an old technology 12MP G1. The next post will be the results of a shoot-out I did between a 12MP GF-3 and the 16MP OMD-D, and give the above performance, the PL45 seemed a good choice of lens to use for the comparison.

-Najinsky

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BJL
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