Blackmagic 4K or Sony a7s with Atomos Shugon?

[oferlevy]

Hi all,

 

I am hoping to start working on a wildlife documentary about the Peregrine Falcon in a few weeks as this is the right time of year for this project in Australia.

 

I am hoping to use my Canon lenses - Canon EF 300, f2.8, L IS, Canon EF 800mm f5.6 L IS, Canon EF 70-200  f2.8 L IS and Canon EF 24-70 f2.8 L IS.

 

I will do all my work in very good light conditions so I am not worried about the poor low light performance of the BMCC 4K.

 

Will always use a tripod - no handheld work.

 

Not going to shoot long sequences and storage is not an issue.

 

The most important considerations for me are:

 

1. Image quality.

2. Compatibility with my lenses - autofucus and aperture control.

 

What should be my best choice?

 

Thanks in advance for any input.

 

Cheers,

Ofer

http://www.oferlevyphotography.com

[Guest Ebrahim Saadawi]

Do you need good in-camera audio? The A7s has a very neat XLR module that attaches to the hotshoe like the C100/300 ones the I love.

Are you certain you can live with 200 ISO? The A7s at 12800 ISO looks similar to 400 on the BM, just without the fixed pattern noise.

Can you live with firmware quirks? No deleting/formating, no histogram, audio meters, etc? The A7s has all of these.

Can you live with an external battery solution? It's a must for the production camera, the battery lasts about 15 minutes.

You choose to live with these pains for only one thing on the BM, which 12 bit raw color. When used in these situations the blackmagic will give you a much more gradable image in post, with better color transitions and compression.

You should choose the BM only if you "need" raw.

If the A7s image quality (8bit 4:2:2) is good enough for the project, I would go with it.

Both will work with EF lenses just fine.

[oferlevy]

Thanks Ebrahim for your excellent input! I was hoping to hear from you! ;)

 

As to your questions:

 

Since I am going to shoot in very good light conditions and shutter speed will always be either 1/50 or 1/60 - I don't need the low light performance of the Sony.

 

Is there fixed pattern noise in the image of the BMCC 4K even in 200 iso and in RAW ?

 

I can live without the histogram as Zebra should be fine for me when exposing to the right in shooting RAW.

 

No need for Audio as I will use external recorder.

 

I can live without deleting/formatting of clips as normally I will shoot 10 minutes maximum in 2-3 hours session a day.

 

Can live with external battery as I work with a tripod only with my long telephoto lenses.

 

I am also hoping to get wildlife material as stock footage so I do need the best image quality so yes to RAW.

 

Even with the Atomos Shugon when shooting RAW the Sony won't give me as good image quality as the BMCC 4K RAW?

 

Thanks!

[froess]

Hello Oferlevy,

 

The Sony A7S doesn't shoot raw with the shogun, it shoots prores 8 bit 4:2:2.

[blafarm]

Hello Oferlevy,

 

The Sony A7S doesn't shoot raw with the shogun, it shoots prores 8 bit 4:2:2.

 

 

The statement regarding the lack of raw output is absolutely correct.

 

However, it is not really a comprehensive answer.

 

In actuality, the Sony A7s outputs uncompressed 8 bit, 4:2:2 via its HDMI port to the Shogun, which in turn can be used to record ProRes, DNxHD or  Cinema DNG.  And, for the record, the reason the DNxHD codec is not included in the Ultra HD 4K category is because Avid has not yet released their Ultra codecs.

 

Codec / Format Support

 

Ultra HD 4K:
Apple ProRes HQ, 422, and LT (10-bit, 4:2:2)
Cinema DNG Raw

HD:
Apple ProRes HQ, 422, and LT (10-bit, 4:2:2)
Avid DNxHD (10-bit, 4:2:2)

[dhessel]

In actuality, the Sony A7s outputs uncompressed 8 bit, 4:2:2 via its HDMI port to the Shogun, which in turn can be used to record ProRes, DNxHD or  Cinema DNG...  

 

Just avoid confusion, while it appears that it is possible to export this uncompressed to Cinema DNG that doesn't make it raw and doesn't make it the same as a DNG from Magic Lantern or a Blackmagic Camera. It is still 8bit 4:2:2 just in a dng container which won't be very well supported since technically DNG should only hold raw bayer data, even though adobe seems to support this. I see a lot of posts around mentioning exporting to DNG and unless you are converting a different raw format to DNG there really is no point, otherwise there are far more efficient codecs/containers to go with.