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

Started Jan 29, 2014 | Discussions thread
blue_skies Forum Pro • Posts: 11,650
Re: Thanks for admitting it finally.

Lab D wrote:

blue_skies wrote:

Lab D wrote:

blue_skies wrote:

Lab D wrote:

skyglider wrote:

blue_skies wrote:

How so: in equivalence terms, the Oly 12-40/f2.8 becomes 24-80/f5.6 versus the Sony 24-70/f4.0?

Hi Henry,

I understand how the Oly 12-40mm is equivalent to 24-80mm in 35mm terms because of the 2x crop factor of the micro 4/3 sensor. But AFAIK, the aperture remains the same.

Aperture is the same.

Think of it this way:

A fat lady and a thin supermodel are laying on the beach. Who will get sun burnt faster? Answer: both will burn/tan the same despite the fat lady having 4x the skin area. This is because they both have the same exposure. Anyway, Four Thirds is the hot supermodel.

F/2.8 is the same for a Nikon 1, an RX100, the E-M1 and the A7.

f/2.8 = f/2.8 = f/2.8 across formats - same exposure. WE AGREE. You see? BUT THE NOISE LEVELS ARE NOT THE SAME.

Yes, and you know noise levels are NOT 2 stops different and dynamic range is NOT 2 stops different for these cameras. Dynamic range is about 1/2 stop for the majority of ISOs DxO tested.

Here is what you link shows. As we agree, from ISO150 to ISO10000 (the most common range), there is maybe 1/2 stop. Interestingly, I didn't see before that sometimes it is only one third.

Thanks for this, and thanks for admitting the truth. If you adjust for the difference in the F/2.8 and F/4 lenses, we can see which the better camera is.


Please go take ISO 6400 pictures with your EM1 then

You conveniently deleted that I stated that it is immaterial whether it is 2x, or 1.65x, or 1.5x stops. It is immaterial, imho, as I would not use a smaller sensor camera at higher ISO. Why not? Because the image quality degrades too much. I would rather use longer exposure and lower ISO, if possible.

And we have had this discussion so many times already. Why the nitpicking?

Lower the ISO, and both cameras are great. They both have their pros and cons.

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