Another Olympus E-M1 and SONY a7 walkabout test, high ISO

Started Jan 29, 2014 | Discussions thread
Anders W Forum Pro • Posts: 21,468
Re: Thanks for the truth!

blue_skies wrote:

Anders W wrote:

blue_skies wrote:

Anders W wrote:

Henry showing the difference between sensors

Lol, instead of 2x I will use 1.5x for A7 and 1.8x for A7r. So, at equivalency, the M1 will be slightly better?

Sorry but apparently you still didn't get it. As you can see from the diagram above, the E-M1 is about 1.5 EV ahead for equivalent images and about 0.5 EV behind for non-equivalent ones (same exposure, different DoF).

Hopefully, you also remember this part of our exchange:

Henry said: and the difference, even per DxO, they rate the ISO performance for the cameras as EM1/A7/A7r as 757/2248/2746. Two stops would have been 3028. So we all agree?

Anders W said: Not quite. While these figures too show the difference to be less than two stops, they underestimate the actual advantage of the E-M1 for equivalent images. The DR curve posted by Lab D provides a better indication with regard to shadow noise, which in turn is the most apparent problem in high ISO shooting. What the curves indicate is that the E-M1 is about 1.5 stops ahead of the A7/A7R for equivalent images (DoF held constant) and about 0.5 EV behind at the same exposure (and different DoF).

But the A7/r do allow trading DOF and noise.

So of course does the E-M1. It's just a matter of how far you want to take that trade. If, as a rule, you don't want more shallow DoF than you can get with a fast MFT prime, you will lose rather than gain signal-noise performance by choosing the A7/r.

We are only as relentless as you force us to be.

Lol, that is because you take every statement and keep adding and rebutting.

No that's because you persist, in the most arrogant manner (just look at your first reply to Lab D here) in repeating your factual errors.

Lab D has a history of being very arrogant to a number of specific people, including me, hence the tone of my response. Sorry if that hit a nerve, but I am merely responding to him.

I am not familiar with that history. Could you please exemplify.

Furthermore, you were factually wrong and he was right. Why not learn from those who know more rather than treat them with scorn?

As to the graph that you keep posting, I think that is a very specific interpretation. It is an 8Mp print measured graph, not the actual sensor/image resolution, and there have been lots of debates on this.

DxO normalizes the pixel count to 8 MP in order not to disadvantage sensors with higher pixel counts in comparison with sensors with lower. What's wrong with that?

Please read and correct or not, it does bring enough questions to the table to try to understand what DxOMark is measuring.

I have read that long ago. So what?

I think that DxOMark should be applauded for what they did, and - to my very simple naive interpretation - they put out an ISO level on their score page which I do find relevant for the various sensor formats.

I have already explained why going by that score is not a good idea.

Each camera model begins to exhibit visible noise at their rated ISO level - I can attest to that from my own usage, as well as the various reports that are out there (dpreview).

Each camera model exhibits noise at every ISO, just more or less so. The point is that the DxO ISO score does not reflect signal-noise performance where it is worst and therefore the most disturbing: in the shadows.

DxOMark also reports an overall sensor score, and lens+camera combinations. You may agree or disagree with their metrics, but they do help interpreting the data.

No, they don't help me interpret the data. I ignore the scores, and the same is true about virtually all technically knowledgeable people I am aware of. If you understand the measurements, there is no reason to rely on arbitrary scores.

DxOMark shows, per the ll article, that larger sensors do not maintain the efficiency of smaller sensors, so "there may be some headroom left for the engineers/manufacturers". And it highlights your claims that smaller sensor perform better, in comparison.

Yes, smaller sensors tend to have better efficiency.

But I agree with the DxOMark interpretation: larger sensor outperform smaller sensor. At least in terms of noise. They have hang their ratings on this for a long time, and many do agree to their way of classifying cameras (and sensors).

Larger sensors outperform smaller in terms of noise only if DoF is left out of the IQ equation. That's an arbitrary decision with which I don't agree. If this arbitrary decision is reversed, it's the other way around.

How much, and by which difference - that is a long debate going on here - technical or not, when I see images side by side, I see less resolution and more noise on smaller sensor cameras. Perhaps the images are not matched in equivalency, and your reasoning holds up, but I would not shoot a small sensor camera at high ISO while I would not be afraid to shoot a larger sensor camera at high ISO.

I am afraid that what you'd personally do or not does not amount to a compelling argument.

Theory or not, practicality prevails. I am happy with my low light/low noise results. Perhaps your equivalency analysis holds merit, I am trading shallow DOF when lights are low (indoors), or I use the flash to get a different effect.

As a rule, I am not interested in trading more DoF than I can with a fast prime on MFT. Flash is of course an option regardless of the sensor size.

With a smaller format sensor, I already feel like being in a corner - hence the migration to larger sensors.

I don't. On the contrary, the smaller sensor buys me more versatility.

And sorry, per all the discussions, I do not see m43 matching FF for low light applications.

It outdoes FF for low light applications when DoF is considered.

You may say that DOF gets too shallow, I would say that DOF gets too deep.

Can we agree to disagree?

This last point is not a matter of fact but of preference so I have no trouble agreeing to disagree.

 Anders W's gear list:Anders W's gear list
Panasonic Lumix DMC-G1 Olympus OM-D E-M5 Olympus E-M1 Panasonic Lumix G Vario 14-45mm F3.5-5.6 ASPH OIS Panasonic Lumix G Vario 7-14mm F4 ASPH +28 more
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