A7s or GH4 - which for you?

[Clive McLaughlin]

Originally Posted by Gary Huff

I have not seen anything from the A7s which looks substantially better than the GH4. Low light capability? What are we talking about exactly? What ISO are you planning on shooting at primarily that the A7s will achieve better than the GH4? 6400?

To me, "low light" is primarily clean at 1600 with acceptable results at 3200. After that, I start cringing no matter which camera.

if its low noise its low noise, I'll push ISO as high as a cameras allows me.

According to the above video, ISO 50,000 is useable.

It all comes down to you specific needs.

For me, I do evening receptions at weddings which force me to shoot high and sometimes noisey whilst also shooting wide open with a very narrow DOF.

If the A7S allows me to bump up the ISO noise free, and open up my depth of field with an aperture of 2.8 or 4 - Then that is a massive massive boost for my product quality.

If you aren't shooting ultra low light, then I guess the A7S is maybe not worth it. But for me... it might well be.

[Gary Huff]

Originally Posted by Clive McLaughlin

If you aren't shooting ultra low light, then I guess the A7S is maybe not worth it. But for me... it might well be.

Yeah, 50,000 ISO is very "ultra", but I would never shoot that as a general rule. I get antsy once I get up to 6400, but I have shot at 10,000 ISO with decent results on a C100 and NR turned up in the picture profile.

[Nicholas de Kock]

You can't really tell noise levels from web videos, they are so compressed there isn't enough data to show how much noise there really is. Personally I easily shoot 8000 ISO on my C100 heck I even push it to 16000 with NR & sharpness turned on because the codec & web videos are so compressed my clients can't tell the difference, it's only us video fanatics that see it. Last time I checked non of you are buying my videos so why are we stressing if the general public only cares about content?

[Noa Put]

General rules don't apply for weddings, you either get the shot or you don't, I shoot between 3200 to 6400 iso all the time at dark venues during weddings with my gh3, I just don't have any other choice because if I would shoot at 1600 iso to get "acceptable" results I often wouldn't have anything to look at because it's way underexposed. Light is often also no option so I always work with available light, shooting at these ultra high iso makes a lot of difference when choosing either a better f-stop and wider dof or just be able to expose every imaginable situation in the way you can see it with your own eyes, even if they turn of the light.

[Clive McLaughlin]

Exactly Noa,
The low light is probably the first thing i want to know about any potential new purchase for me.

And for now, as a wedding videographer primarily, delivering on DVD and HD compressed mp4 online - I would far rather invest money in low light HD than 4k with no significant low light improvements.

You don't buy for the boast factor, you buy to meet your specific requirements. 4k is not a requirement to my business at present.

[Steve Burkett]

Originally Posted by Clive McLaughlin

.
You don't buy for the boast factor, you buy to meet your specific requirements. 4k is not a requirement to my business at present.

I quite agree. Each year there's a new gimmick for the video community to get excited about, last year it was RAW video, before that Black magic. I didn't jump on any of those bandwagons despite my interest and awareness of their advantages as I couldn't justify the cost in terms of business requirements. It would be a vanity purchase, nothing more.

As it happens I'm buying the GH4, not to be seen as uptodate, but as an owner of GH2s and a GH3, its a logical upgrade with several new useful features, one of which is 4k. I'm aware there are better cameras for lowlight, but in the end, I'm sticking with what I have. If I jumped to another camera manufacture every time someone said it was the best option for video, I'd be buying 4 or 5 cameras a year.

[Nigel Barker]

With a 5D3/C300/C100 you can shoot shoot noise free ISO6400 at F/2.8 & your footage will end up looking a lot brighter than the location ever was. I don't see why you really need low light capability better than this.

[Arthur Gannis]

Originally Posted by Nicholas de Kock

The GH4 actually does 4K, the A7s doesn't. Sony has a line of professional cameras to protect like the FS700, F5 & F55, they won't release a DSLR that competes with those. Panasonic is more flexible they don't have such a protected high-end line so no reason to cripple the GH4. If history (A99) is anything to go by Sony loses here.

I think the Sony A7s is capable of doing 4K. What is the Atomos Shogun used for ?? http://www.popphoto.com/gear/2014/04...order-sony-a7s
The A7s just doesn't capture 4K within the camera itself, but I am sure it will do a fine job with that FF sensor.

[Clive McLaughlin]

Originally Posted by Nigel Barker

With a 5D3/C300/C100 you can shoot shoot noise free ISO6400 at F/2.8 & your footage will end up looking a lot brighter than the location ever was. I don't see why you really need low light capability better than this.

Yea but at what aperture? Super shallow? Thats not enough. We shouldn't have to limit our 'look' and make focusing a difficulty.

Take this following pieces for example - The shallow DOF drives me mad in it, but no doubt the shooter didn't have much choice. i'd rather be at f4 or 5.6 for this.

https://www.youtube.com/watch?v=azMDBfmxwqA#t=80

I'm not sure ISO 6400 cuts its at those apertures. If ir doesnt, I need to test my 6D properly in case I'm not using its full potential. I've never even tried going past ISO 3200.

[Dave Partington]

Originally Posted by Clive McLaughlin

Yea but at what aperture? Super shallow? Thats not enough. We shouldn't have to limit our 'look' and make focusing a difficulty.

The quote in your post said f2.8. Let's use that as a starting point. f2.8 at 16mm gives a lot more DOF than f2.8 at (say) 200mm, so before discussing usable DOF we first need two things, aperture and focal length.

I've shot at ISO12800 on the 5D3 when no other shot was possible. A little kiss from neat video brought it to an acceptable result (good enough for the client).

[Noa Put]

Originally Posted by Arthur Gannis

I think the Sony A7s is capable of doing 4K

The a7s can do 4k, only not internally but only out to a ext recorder.

[Gary Huff]

Originally Posted by Noa Put

The a7s can do 4k, only not internally but only out to a ext recorder.

And only via HDMI of which the Atomos Shogun is the only option I am aware of, and it doesn't ship until August/September or later.

On the other hand, the GH4 will allow you to record 4K as soon as it's in your hands. AVCHD 4K variety, but 4K nonetheless.

[Dave Partington]

Why bother with 4K when 8K is just around the corner ;)

NAB 2014: 8K resolution coming in 2020 - News - Digital Arts

[Nicholas de Kock]

Originally Posted by Noa Put

The a7s can do 4k, only not internally but only out to a ext recorder.

AKA it doesn't do 4K! In my books a camera only does 4K if it does so in-camera, it's just a marketing gimmick. How many people will be running external recorders?

[Noa Put]

Eventhough it cant do it internally you would have an option to shoot in 4k, so it can output to 4k if you have the need for that. I also wouldn't call being able to shoot 4k 4:2:2 a marketing gimmick, there are many people that run external recorders, sometimes to bypass the 30 minute recording limit or to just get a higher output quality out of their camera, that's nothing new. It might be a technical limit that the a7s can't do 4k internally or maybe Sony just wants us to buy a external recorder as they are so into accessorizing.
The gh4 applies the same principle, but their brick is even worse, it also adds functionality that the camera itself doesn't have, you need to have powering solutions and a external recorder making this combo useless as a run and gun solution, but it can do 4k 4:2:0 internally, I only would see that useful for it's cropping abilities, outputting a 4k master is useless right now, it will eventually change but the chance is that when that happens you have probably replaced the camera with another model.