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A more realistic impression of the Sony A7S low light performance at ISO 12,800


Andrew Reid
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It's funny how some people they're trying to reduce A7s qualities in favor of GH4... It feels urgent to prove GH4 is finally up there with the big boys...

Right now 1080p is the reality and in 1080p world GH4 is nothing really special. Even a seriously compromised camera like 5DmkIII from 2+ years ago still holds its own against GH4. As for GH4's low light capability it's still stuck in 800 iso from back in the day... However, I really believe that GH4 is a great camera but a bit overhyped. On the other hand A7s is not out yet so we can only speculate. Enough is enough with biased conclusions, it is just a matter of time before we know what is all about.

Be patient 4K is not there yet and by the time it will be there will be much better cameras than GH4, A7s etc. 

 

 

Agree 100%.... 

Really funny indeed

 

Indeed Mr Andrew, we now have a more realistic impression of the A7S low light performance.... : 

 

"High ISO output: What can I say? Dumbfounded. I expected high ISO to be good, just not this good. All the JPEGs you have seen give no real idea how usable the ISO is on this thing! I will let you play with the RAW and JPEGs yourselves to determine what your own 'usable limits' are as everyone is different, but to me ISO 51,200 is about where 6400-12,800 is on my A7."

http://***URL removed***/forums/thread/3685321#forum-post-53852362

 

And as far as video... Why look at jpegs ? We had some real video exemples which all look AMAZING, so whatever the jpg, the video is different ... And sorry but if it looks THAT good on youtube, can only be even better uncompressed..

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yes, the camera is amazing. at iso 25600, 32000, 40000 or 51200 it will be possible to use f5.6 at night in streets or in day dark interior. this will make all lenses useful in all situations. lenses like the sigma 12-24mm f4.5-5.6, tokina 17mm f3.5, sigma 8-16mm 4.5-5.6 (with aps-c cop) sigma 10-20mm f4-5.6 (also with aps-c crop), cheap old vintage full frame zoom lenses and many other slow lenses will be useful with this camera.

 

about DR, I do not expect more than 11 fstops. it is the same technology present in a6000 sensor, just the size and megapixels change, so with dro5 and highlight recovery in post I believe 11 fstops dr will be the maximum, but 11 fstops are pretty good.

 

new sensor technology will come to give us more dr in near future... to make possible to do what magic lantern hdr does without the need of different iso in adjacent frames...

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Guest Ebrahim Saadawi

"High ISO output: What can I say? Dumbfounded. I expected high ISO to be good, just not this good. All the JPEGs you have seen give no real idea how usable the ISO is on this thing! I will let you play with the RAW and JPEGs yourselves to determine what your own 'usable limits' are as everyone is different, but to me ISO 51,200 is about where 6400-12,800 is on my A7."
http://***URL removed***/forums/thread/3685321#forum-post-53852362

.



The 102.400 ISO samples in that Dpreview post look better than the 12.800 in the OP. Mind. blown.
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There is an interesting difference between the "total" dynamic range and the "usable" dynamic range. If the picture style is rated to give more than 11 fstops, maybe this is subtle differences that does not make significant perceiving in the real world, maybe due to this the T3i just shows 9 fstops difference when pointed from the black to the white image in the computer monitor even using a flat picture style.

 

It would be interesting to see what would be the "usable" DR in the A7S. Good thing to do would be to compare the same contrasty scene with different cameras.

 

Interesting article about usable DR:

(it says that BMCC usable dynamic range is less than 10 fstops, if this is true, 9 fstops usable in T3i is ok)

 

http://www.cinemadigital.pt/index.php/videos/item/111-arri-alexa-blackmagic-red-epic-comparacao-sobrexposicao

 

http://www.ryanewalters.com/Blog/blog.php?id=8375868975844575706

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And as far as video... Why look at jpegs ? We had some real video exemples which all look AMAZING, so whatever the jpg, the video is different ... And sorry but if it looks THAT good on youtube, can only be even better uncompressed..

 

Completely agree. The processing that takes place for videos is way different than for stills, and with that in mind ISO 12,800 looks this awesome! That is from a VLC snapshot of the downloaded footage from Youtube. If it looks that good in Youtube, for sure it looks even better uncompressed.

 

vlcsnap-2014-06-16-06h43m38s80_zpsdbde48

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Completely agree. The processing that takes place for videos is way different than for stills, and with that in mind ISO 12,800 looks this awesome! That is from a VLC snapshot of the downloaded footage from Youtube. If it looks that good in Youtube, for sure it looks even better uncompressed.

 

vlcsnap-2014-06-16-06h43m38s80_zpsdbde48

 

Mega crushed blacks and lots of compression hides noise.

 

ISO 12,800 does not look that clean on the A7S. I guarantee it.

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Den Lennie : "looks like f5 footage with 15+ stops of DR and great resolution and detail"

 

 

Nothing against Den as a person but I'm calling BS on that one.

 

Dan has the official promo material for the A7S. In this instance his job has been as a product evangelist, not an impartial technical guy with a critical eye and deep technical understanding of the technology.

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What this jpeg fails to show you is just how dark it is in the shooting environment is.  f/1.8, 1/100s, ISO12800 for that level of exposure....it is very dark.  Of course there will be noise for stills.  I'm sure video will go through many tricks of noise reduction.  

 

What's surprising is noise filtering on stills work extremely well.  Virtually remove all the noise without visible loss of detail, without sharpening and still maintain that sharp look.  I've never seen noise filtering work so well in such a noisy image.

 

False alarm.  This camera is still amazing.

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Mega crushed blacks and lots of compression hides noise.

 

ISO 12,800 does not look that clean on the A7S. I guarantee it.

 

Here's an ISO 12,800 from an A7s raw with the same dimensions as that screen shot. This one doesn't have crushed blacks, luminance NR or lots of compression and looks very clean to my eyes:

 

i-JwsJ9ts.jpg

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Mega crushed blacks and lots of compression hides noise.

 

ISO 12,800 does not look that clean on the A7S. I guarantee it.

 

Well, what about the "darkness" movie shoot between 8000 and 40000 ISO ? was super clean. 

 

By the way ... first test of the A7S by luminous landscape: 

http://www.luminous-landscape.com/reviews/cameras/sony_a7s_first_impressions.shtml

 

"- I have to say that the Sony A7s produces some of the cleanest, most pleasant images I’ve seen this side of a medium format system.
– On the basis of these tests I would judge the A7s to have almost a three stop advantage over the A7r between ISO 6,400 (which is as high as I would use on the A7r)  and ISO 51,200 where the A7s reaches its useful limit (for my type of shooting)."

 

3 stops advantage ....... 

I think you have been too fast and hard about the A7S on this article Andrew ;)

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I have A7S sample images that I personally took. While I forget to set some settings (notably AF), my impression from the JPEGs is that I'm going to side with Andrew here. It's simply not that clean. I might try some video another day.

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DxO results are in! ISO score takes the top spot as expected. What is unexpected is DR at low ISO. Perhaps the other cameras enjoy a bigger DR boost (as well as color depth boost) from downsizing to 8MP?

 

Versus2.jpg

 

But it's the usual story at DxO, using only DR at the lowest ISO in their scoring. This is of more relevance to me:

 

34t4bvp.jpg

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So it looks like A7S is not (all)low ISO king.

It is high ISO king (where the difference from competition is getting big).

 

Can someone explain to me Tonal Range and Color Sensitivity measurements and their impact on video?

 

For example at ISO200 tonal range:

A7s - 9bit

GH4 - 8bit

 

But with external recorder you have GH4 10bit compression and A7s 8bit compression. So they will have the same tonal range in the end (GH4 8bit packed in 10bit, A7s 9bit shrinked to 8bit)?

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