I truly enjoy that second image...nice play of foreground visibility vs. starry sky...
It'll be interesting to see where a favorable balance of ISO, aperture and shutter speed will work in extreme-low-light situations. Learning the camera's sensor behaviors at various ISO settings will clearly take some in-the-field testing.
I bring this up because of your settings for that second image...15 sec @ 12,800 ISO (you don't state f/stop). Bumping up the ISO in an attempt to freeze the wave action we get...
...and, clearly, one would be pushing ISO to quite the extreme to try and do so.
Comparing your shoreline image settings (I'm assuming f/4) with the similar shoreline framing at 1/25 sec, ISO 40,000, f/1,4, in this video it's clear that your scene was at least 3-to-4-stops stops darker. (See video at 3:36 mark for how shots were done). Low light video test of a7S from Philip Bloom... ...Show more →
Thanks Jimmy. I used a 15 second exposure because that's the shortest exposure which avoids stair trails @ 24mm. The aperture was f/5, which is necessary to get some extra corner sharpness on the 24-70 f/4 FE (24mm is its weakest focal length and it would actually sharpen up even more beyond f/5). The exposure was ETTR by about 1 1/2 stops, which the DR of the scene permitted and so it allowed me to use a higher ISO at the same absolute exposure (same f/stop and shutter) to get a further reduction in shadow noise in that scene.
One thing I noticed is that the A7s has pretty significant hot pixels even at the modest long exposures I used. This was first reported here. I didn't use long-exposure NR because it's not available for the fully-electronic shutter mode I used for the above images (since LENR would require closing the shutter to take the dark frame). I'm using the fully-electronic shutter to avoid the amp noise/glow that occurs on the A7s at ultra low exposures (I compared that here) - I haven't tested whether LENR would remove the amp glow as effectively as the electronic shutter does.
I've trained my dog to pose for treats. She knows after a certain number of shutter clicks she'll get one. The A7s's silent shutter leaves her confused and underpaid
snapsy wrote:
Thanks Jimmy. I used a 15 second exposure because that's the shortest exposure which avoids stair trails @ 24mm. The aperture was f/5, which is necessary to get some extra corner sharpness on the 24-70 f/4 FE (24mm is its weakest focal length and it would actually sharpen up even more beyond f/5). The exposure was ETTR by about 1 1/2 stops, which the DR of the scene permitted and so it allowed me to use a higher ISO at the same absolute exposure (same f/stop and shutter) to get a further reduction in shadow noise in that scene.
One thing I noticed is that the A7s has pretty significant hot pixels even at the modest long exposures I used. This was first reported here. I didn't use long-exposure NR because it's not available for the fully-electronic shutter mode I used for the above images (since LENR would require closing the shutter to take the dark frame). I'm using the fully-electronic shutter to avoid the amp noise/glow that occurs on the A7s at ultra low exposures (I compared that here) - I haven't tested whether LENR would remove the amp glow as effectively as the electronic shutter does....Show more →
Hi Snapsy,
Thanks for the followup info on your exposures, and for those links about some of the various noise issues. I had read that there was a difference in image noise between Single Shot Silent and Conitnuous modes on this camera...Continuous being about a stop worse...from here...
As for hot pixels during long exposures, none of my Canon's are free of that issue. (Sigh.)
Again, my interests with this camera are its low-light sensitivities...Sony has broken some new ground here...even amongst its own line up. My hope is that Canon will have an answer to this with their new low-light sensor which they announced last year...
...now THAT would be a shootout I'd like to see! I'll be holding off any purchasing decisions until I see what Canon does between now and springtime.
In the meantime, I'm looking forward to this camera getting into some more hands and seeing this thread populate with such images!
As for the camera's video low light performance, well, after viewing this video I can see I'll be having to do a bit more homework on their Picture Profile 7 SLog settings!...
Keep them coming. I personally am glad to not have to scan through the A7/R thread to see 7S pictures and read about people's experience with them. Cool stuff
