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

Started Jan 29, 2014 | Discussions thread
blue_skies Forum Pro • Posts: 11,553
Re: He'll never learn

Lab D wrote:

blue_skies wrote:

Lab D wrote:

The service that DxO provides for sensors is that you can look at the graphs and determine how a sensor will perform at a given ISO. Since some systems have slower zoom lenses, you can also compare while adjusting for the differences between lens apertures by look at different ISOs.

So, when you look at the A7/A7R and the E-M1 for ISO1600, you can easily see the difference in DR is about 1/2 stop. The "overall" score is obviously not helpful here and if anything is wrong for that situation. Now if you want to compare the cameras with their fastest available native zooms, you can read the E-M1 line at ISO800 and compare to the A7 at ISO1600. Again this is far more accurate than trying to use those overall scores.

It frustrates me when newbies only look at the overall DxO scores and don’t understand what they mean. What is worse is when they don’t look at the actual findings which better represent reality and all the specific situations you may run into.

Your frustration is loud and clear.

Also, many of your posts frustrate others, but I guess that that does not count....

This is because we present facts tht conflict with you desired outcome (dream). Of course you get frustrated.

We know that some here don’t want to know the truth and have other motives. :


btw, you are right. When people mention "equivalence" they ar talking about using the same DoF. When you do that these days the smaller sensor wins for SNR and other measurements. As long as the smaller sensor can give you the shallow DoF you want, it will perform better than the larger one IMHO.

It is simply to hard to have a conversation with you, you constantly keep bringing up different points (facts) and changing topics (presenting actual facts).

Perfect example. When we are comparing how 2 cameras will perform at various ISOs, rather than look at the measurements for those ISOs, you only want to use the overall scores which are meaningless in those situations. Then when we are discussing the difference in apertures for 2 lenses so we can judge real world results, you want to ignore those differences because it conflicts with your desire outcome.

Here is the reality. If we want to take a picture with an A7 and need the DOF of an F/5.6 lens and need to shoot at 1/60 of second and ISO3200 to expose the image properly, we will find that the E-M1 does a BETTER job with higher IQ (less noise more DR) because we can use F/2.8, 1/60 and ISO800 while achieving the same FoV and same DoF.

And we have come full circle:

Thanks for the samples, they are very helpful.

I would remind everyone that Olympus has wider aperture lenses and IBIS too. This means if you use the Olympus 12-40mm F/2.8 as a walkabout lens, not only will you have a greater range and more uses (also a great close-up lens), but you will get 1 extra stop of light over the new Sony 24-70mm F/4 lens.

And if you are using primes, the FE primes don't have IS, so the IBIS will in some cases also give you a couple extra stops advantage.

For me it doesn't matter. There are no avaialbe long lenses fo rthe A7 and the focusing is still not good. For me the Sony is not even a consideration because it can't do what I want.

My point, that the f/4.0 on the A7 was a stop faster still holds, as you compare f/5.6 versus f/4.0.

Again, the A7 has a f/4.0 lens and the M1 has a f/2.8 lens. You can therefore not match DOF and reach equivalence with the A7. The A7 is one stop faster - shallower DOF with less noise.

So, per your text above, I think that you finally agree with me on this one.

As to the other discussions, f/2.8 is a slow lens (f/5.6 on FF). More typically (I use) are f/2.0 and f/1.4. They do not (really) have equivalences on m43, meaning that the two formats are best used differently (in terms of DOF/Noise/IQ).

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