BMCC EF vs Sony A7s for a feature film with a lot of night shoots?

IronFilm

How does the A7s and the BMCC compare against each other?

Because I've just joined on as the DoP to shoot a feature on a BMCC, but given the nature of the film (shooting most of the time late at night), am wondering if a Sony A7s is better.

Am curious about some direct comparisons between an A7S and a BMCC at night, and how they'd be able to grade, and how they'd be used in practise with lighting set ups (as if we can use a smaller lighting kit, that might help mitigate some of the cost of an A7S), their look, etc.

As if so, I might then recommend to the director trying to find space in the tiny budget to switch to a Sony A7S instead.

What I really wish Sony would do is make something like an A7S version of the Sony A5100. So perhaps an APS-C version with merely a 5 megapixel sensor and the same amazing low light performance as the A7S but with the cheap price of the A5100!

As I don't need a "full frame" sensor, neither do I need more than 5 megapixels so as to have enough for 4K video. I'm content with 1080p.(after all, even with the A7s, most are not shooting 4K because it doesn't do internal 4K)

Unfortunately I don't think a 5 megapixel camera would go down well at all with the typical 2014 consumer, even though I've shot plenty with my old Nikon D50 which was only 6 megapixels. So I think 5 megapixels would do just fine for casual photography, especially as it would be a very very good 5 megapixels. (plus of course I wouldn't be getting it for photography, but video)

andyharris

I have both the BMCC 2.5 and 4K cameras. They are best at ISO400. Using Resolve you can mask a fair bit of the noise.

If your subjects are well lit and you want a black background then the BMCCs will do it. Otherwise I'd choose a camera that likes the dark a bit more. I'd use a 5D3 with a fast lens by choice. Mr Bloom has a blog post on a Sony in the dark.

IronFilm

I've got the Nikon D5200 which is basically as good as the 5DmkIII in low light.

But I strongly doubt the director would be wanting to shoot the feature with the D5200.

Ralph_B

Shooting with the A7s at night will bring a smile to your face. There really is no comparison. You can shoot at ISO 12,800 with very little noise. You can use the high ISO's not only for low light, but to stop your lenses down to get more depth of field as needed. The XAVC codec is excellent and grades superbly.

Also, I'm not sure the A7s is actually more expensive than the BMCC. The BMCC will end up costing more when you factor in the added cost of media and hard drives required to hold the much larger file sizes of prores or raw. And that difference in price could be considerable for a feature length project.

But I wouldn't base my decision on anything anybody says in a forum. Everybody's needs, priorities and aesthetics are different. If at all possible, try to check out the cameras yourself.

IronFilm

Won't base the decision just on what people say on forums :-) But it is a way to get a wide range of opinions on it, which I can then give various weightings to as part of the decision making process. And am trying hard to find somebody local to borrow the camera from, found one rental place with it, so it looks like that is what we'll be doing.

A7s is quite a bit more expensive when using the Atomos Shogun with it. And once you're recording 4K ProRes files on the Shogun I doubt you're making any space savings there.

kevin_kirchman

@ironfilm, If you don't need 4k, the A7s is a great 1080p camera, for a bit cheaper than a kitted out BMCC. I recently shot a short film on it and a lot took place at night, and wow, was I thankful to have the A7s as opposed to the Gh4 (which in its own right is an awesome camera). As mentioned above, the codec is solid, noise is really nice (not the old Canon style noise), a lot of detail, etc.

That being said, I haven't used a BMCC at night so I can't speak to it. I have used a BMPCC in minimally lit situations, leading to some mixed results, but if you can light the scene, these cameras really shine.

hempo22

I've used both cameras at night. I sold my BMCC package for the a7s, never looked back. If you want a stronger coded (XAVC-S is really good) the ninja star is a good companion.

DrDave

No comparison at night, A7S.

IronFilm

@kevin_kirchman I want/need a monitor & recorder, I'm right on the edge of buying a Atomos Ninja Blade. But if we use the A7s it starts to make sense to spend just $1k more than the Ninja Blade and instead get the Atomos Shogun I suppose.

" I sold my BMCC package for the a7s"

@hempo22 could you go into more detail why you sold your BMCC for the A7s and the kind of work you're doing with it? What about in well lit situations, surely you're worth keeping the BMCC for that?

hempo22

partly because I missed stills photography. Second because I rarely have enough budget for light when shooting at night.

I'm a one man band most of the time and BMCC with prime lenses and mattebox with filters and battery packs and converters and heavy duty tripod was just too much for me. I spent most of my time carrying and putting together or take it apart instead of shooting. I wanted a smaller form factor and a run and gun setup.

balazer

I have an a7S and a BMPCC. I pick the a7S every time. Day or night.

The BMPCC was an exercise in frustration. No histogram or exposure meter means you need an external monitor if you want to get the exposure consistently right. No sound level meters means you need an external meter and/or recording. Limited ISO settings (really just 800 and 1600) and limit shutter speed settings (45 degrees minimum) mean you need ND filters and lights. The log recording is useless - you need to shoot raw if you want any kind of quality. But Davinci Resolve doesn't decode DNG images correctly, making it difficult to get natural colors. Adobe Lightroom and dcraw decode DNGs well, but they are not geared towards video. The display is washed out and not good for much except framing. The buttons and menus are clunky.

The Sony a7S just feels like a professional, well-rounded product. It's not perfect, but it brings so many features that make it much easier and more enjoyable to use. It has a wide range of ISO settings: the thing can see in the dark - it's amazing. It has a wide range of shutter speed settings, exposure meter, continuous auto exposure, histogram, good internal audio recording with meters, sharp 1080/60p with low jello in the APS-C crop mode, and great stills shooting.

The workflow is different. You have a few choices

standard gamma & color: best if you like to get your exposure and white balance set in the camera and do minimal correction in post
S-Log2 gamma & rec.709 color: good if you know how to deal with log footage and you want to manually map S-Log2 levels to rec.709. The exposure must be set carefully because the S-Log2 curve is not truly logarithmic, and you'll get different results depending on which part of the curve you're pulling from.
S-Log2 gamma & S-Gamut color: perfect for an ACES workflow. I use an ACES workflow in Sony Vegas Pro. Not sure if Vegas is the best choice for creative color grading, but it's very good for doing exposure compensation and color balance. I now use ACES exclusively, and I get more consistently good looking footage with less effort than I ever did before.

racer5

@balazer Might want to update your Pocket's firmware one of these days:p

But yeah, for low light there's no contest with the A7s.

balazer

@racer5, thanks, but I'm not looking back. Audio meters and a histogram aren't enough to make that camera good. These days I mostly use the exposure meter on the a7S, which is far easier.

nomad

One comment on shutter speed: normally you want to shoot 180 degrees shutter for motion and use NDs on any camera if there's too much light – or fast motion will stutter.

balazer

Ideally, sure, you want a shutter speed around 1/50 or 1/60. But if I don't have an ND filter handy or I'm moving in and out of bright areas, on the a7S at least I have the option of using a fast shutter speed. That versatility is tremendous for the run-and-gun style of shooting that I'm usually doing. And depending on how fast the motion is, sometimes the temporal aliasing of a fast shutter speed is less bad than the color shift of a high density ND filter. Temporal aliasing isn't as noticeable at 60p, and it's hard to find a high density filter that's really close to neutral.

BTW I know the OP asked about the BMCC, but the BMPCC is very similar in terms of features and image. They have the same type of sensor, just with different sizes and resolutions. The cameras have different sizes and recording media, of course.

DrDave

When you pick up the Sony, you just get the buzz. I'm not a Sony fan, but that's a great cam.

tinyrobot

Careful of the purple fringing on the A7s. There is a workaround by setting the white balance, but if you are not thinking, it will bite your ass.

AlbertZ

@balazer thank you for your suggestion about ACES workflow, could you please share some footage? I think it would be really interesting for users with little grading experience :)

balazer

I'm working on a tutorial & demo.

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