WOW what a game changer A7s

Started Apr 6, 2014 | Discussions thread
OP (unknown member) Veteran Member • Posts: 9,509
Re: doubt Sony lies, claiming better high ISO performance

Ontario Gone wrote:

RussellInCincinnati wrote:

you are suggesting that the lower resolution will specifically make noise performance better. It won't.

This is a sort of silly prediction. Firstly since there are reasons why larger pixels on a same-size sensor, might make it possible to lower more than one kind of noise. That is at a given display size, for a given level of ambient light, a given lens and aperture, and a given exposure time. Boring details below.

Sensor resolution is only relevant in that it can break a file up into smaller parts before pixelation happens. The pixel represents the smallest unit of detail within the file. It doesn't matter how sharp the lens is, how fast the SS is, how low the noise is, the sensor will only record as much data as the resolution allows. Unless one of the other factors is substantially poor, more pixels will yield more detail.

In the text of our discussion, regarding noise, only sensor portion is important. Of course a larger A7s pixel will be better off than a smaller A7r pixel, it occupies more sensor area. That doesn't represent the entire sensor performance which doesn't change just because resolution does.

In contrast, there are no reasons why smaller pixels will de*crease noise for a given sensor readout after a given exposure time. *_Please let me know if this is not true, am eager to learn._

Well then perhaps DXO needs a lesson too, as well as Sony themselves because everything you said is being contradicted by tests.

So i guess im letting you know now, it's not true, there must be something you are missing and unfortunately im not a sensor engineer. What i can do is read test results like those above. It happens again and again. The NEX7 has higher DR and color depth than both the NEX6 and NEX5n, and is 2 points behind the 5n in noise.

The A77 had better ISO, color, and DR scores than both the A58 and A57. I mean come on you guys, damn near everwhere we look we see test results that say exactly the opposite of what you claim. IQ is not determined by pixel size, it's determined by sensor size. More pixels simply allows us to break it up into smaller pieces. It's very simple, why are we having this conversation?

Secondly, Sony has claimed better high ISO performance for this new camera (presumably compared to other same-sensor-size Sony cameras available for sale before May 2014), and it is unlikely that a zillion-dollar-brand company like Sony would say something so easily and soon proven to be a lie. Sony has lots of brand perception to lose, in both short and long run.

And panasonic claimed the GX7's sensor would offer 20% better noise performance yet it scored worse on DXO than the GH3. Fuji claimed their new XE2 AF was the worlds fastest, and again with the XT1, yet we all know better. Like i said in another post, did you really expect Sony to admit their new video camera is worse in stills? For 4k video im sure it will best everything else because it's pullilng pixel level with near full sized FF light. When you shoot stills from a full sensor read, it's no better unless there is a jump in sensor technology, and that doesn't mean simply reducing resolution.

Ontario: Noise performance is about total light gathered,

Well that is surely the most important factor, but it is a touch misleading to imply it's the only factor. For example you surely do not guess that all cameras with the same sensor size show the same total noise performance.

When you compare similar generation sensors made by the same company, yes, that is by far the biggest factor, so much so that other factors are negligible.

Having said all this, even cheap APS-C cameras don't do so bad in the noise department these days.Ontario why not show us some of your own work, that shows your experience with low light?

Some days it seems all i do is shoot in low light. My posting history is filled with all kinds of low light shots, most around ISO 3200 and as slow as 1/25 @F1.7. Even my older cameras were tested many times, in fact my last camera which was a K5-IIs was bought specifically for it's good noise performance and -3EV AF rating.

One of the reasons i own my current camera is because of my shooting habbits. Im often in low light, calm and quiet atmospheres, so i bought a silent camera that can focus well in low light, and fast lenses. Literally half of my keeper shots (maybe a couple hundred) on this computer are at ISO 3200.

-- hide signature --

"Run to the light, Carol Anne. Run as fast as you can!"

I would not call the GX7 a really great high ISO camera. It is ok (and one of the better M4/3 cameras.) I like mine for other reasons than high ISO.

it is also better than older APSC DSLRs but tech moves along for all types....the new A7s is the latest and is specifically designed for both stills and video.

That shot is not that low light and above ISO 3200 the GX7 ceases to be silent (that is as high as silent/electronic shutter mode will go).

The A7 is much better than the GX7 at high ISO and from what I have seen, the A7s is maybe  a fair bit better still.

If the A7s was put out at the same time as the A7 it would have been a difficult choice for me between them.....maybe still would have picked the A7 but it would have been close.

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