Sony Nex7 low light at iso3200 from a Cinestar 6 hexakopter

J

jeffscholl

Member

Trying out twilight aerials with the Sony Nex7, 18-55, and Cinestar 6 hexakopter. The Nex7 was set at 1080 24P, 1/25th, lens wide open and ISO3200.

Cheers,
Jeff
 
that looks great!
not really sharp (probably because it's downscaled to 720p), but much cleaner than I expected for the NEX-7
did you use any noise reduction software?
 
I've read that the 7N is actually a noticeable step down in low light ability compared to the 5N due to MP increase, I believe. Those shots still look great though with the 7N. What is the aperture when wide open?
 
skital said:
I've read that the 7N is actually a noticeable step down in low light ability compared to the 5N due to MP increase, I believe.
Click to expand...

that's a bit misleading: on a per-pixel basis, yes, there's a lot more noise
but after resampling both images to the same resolution (e.g. 16mpix), noise is basically the same

dxomark make their noise comparisons on an actual print, always of the same size, and say noise is basically the same (after adjusting by ISO differences: ISO 200 should mean the same on all cameras, but it's actually slightly different even in these nearly-identical two)
http://www.dxomark.com/index.php/en../Cameras/Compare-Camera-Sensors/Compare-cameras-side-by-side/(appareil1)/736|0/(brand)/Sony/(appareil2)/737|0/(brand2)/Sony

but I must say all that is in stills mode: in video mode, any shortcuts when subsampling to 1080p will create big noise differences from big mpix to low mpix sensors (they certainly would with canon's line-skipping method, they probably wouldn't with GH2's more advanced method)
 
Your first order of business is to get a F/3.5 maximum aperture off that camera! :cheesy:

Very cool flying video... Just saying if you need more light, seems the answer is in the glass.

BTW, your house is amazing.
 
That was at f3.5. I do have a 16 f2.8 that would have given me another stop of light.
The answer is to use my FS100. Looks pretty clean at 18db :-)

Cheers,
Jeff
 
NormanBates said:
that's a bit misleading: on a per-pixel basis, yes, there's a lot more noise
but after resampling both images to the same resolution (e.g. 16mpix), noise is basically the same
Click to expand...

Not quite. DPreview shows that the 5n is slightly cleaner when the 7 is sampled to same size. The higher the ISO the more pronounced it is.
 
They did it the wrong way around. They resampled 5n to 24megapixels. That's kinda odd. And EVEN there you can clearly see the 7d has way more noise in the blue channel. Look at the first blowup. The 7 has huge amounts of noise, the 5n has noise but not as much. Still they type that "they are the same" eventhough in the images they are not.

Actually meant this page anyway, not dpreview:

http://www.stevehuffphoto.com/2011/10/26/iso-wars-sony-nex-7-vs-sony-nex-5n-full-test-with-crops/

The 3200 & 6400 ISO's show pretty well what I mean. You can see the same issue in the Dpreview shots. 5n is better even after the 7 has been resized to same size.
 
ok, I also thought upsampling the 5n image was odd, and that test clearly shows the downsampled nex-7 displaying more moise than the 5N

usually I'd take dxomark's opinion on these matters as the better test, and their measurements say they're the same
http://www.dxomark.com/index.php/en../Cameras/Compare-Camera-Sensors/Compare-cameras-side-by-side/(appareil1)/736|0/(brand)/Sony/(appareil2)/737|0/(brand2)/Sony
(after adjusting for the fact that ISO values don't mean the same thing in both cameras)

but maybe their "18% SNR" thing is measuring a different thing than what we perceive as "noise": in the high-ISO crops from your link, the nex-7 seems to show better detail in some parts of the bright areas (the / after multivitamin, the T in supplement), but a hell of a lot more chroma noise in the shadows

supposing that test you linked didn't screw anything up with the parameters in each camera, let's leave it at this: the nex-7 seems to have much nastier noise than the nex-5n: maybe it's not more by some standard definition (which is what I guess dxomark uses), but you may notice it way more

thanks for the new knowledge provided
 
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No much info of the Nex 7 for video use but; must be similar to the the nex5n (useles for external recording) even the A77 has no clean output.
 
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