December 29, 2016 at 4:33AM

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A7 for filmmaking

Hi,

I am considering selling my Nikon D5200, to buy a Sony A7 (first generation, 24MP sensor). Here's my question - will A7 be better for narrative filmmaking? Despite of full-frame, I've heard that it has problems with moire and aliasing. Also, if I fiugred out correctly from Sony tech specs, it has a bitrate on 24FPS FHD of 24Mb/s - D5200 is a bit over 30Mb/s.

5 Comments

Alias/moire has little to do with frame size. Still cameras are optimized for still images, not video, especially in cheap consumer cameras (like the A7) which tend to not have anti-aliasing filters (OLPFs). For instance, a high quality full-frame still camera will have an OLPF optimized for 6K images (approximately) but the optical resolution needs to be less than 2K in order to avoid alaising in video. If it's a problem that bothers you as much as it bothers me, it would be better to look into a camera with an OLPF optimized for video, which likely means a video camera instead of a still camera. You also usually get less rolling shutter effect in video cameras. The thing is, a 1" OLPF costs about $200, and a full-frame OLPF costs about $1,300 by itself, which is more than the total cost of the A7!

I can say from experience that you'll get a more film-like image out of a proper 2/3" or 1" video camera than a full-frame still cam. Many major theatrical features have been shot in 2/3" format and nobody in the audience cared. Your D5200 has an S35-sized sensor, which is currently the most common format for cinema. It has less alias distortion than the A7 because the lens limits the resolution somewhat, especially if you have a zoom lens. The smaller the sensor, the harder it is to yield super high optical resolutions, which equates to less aliasing. In fact, 1/2" 3-chip cameras can almost get away with not having OLPFs because of limitations in optics.

December 29, 2016 at 8:27AM, Edited December 29, 8:56AM

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The moire and aliasing of the A7 is accepatble (although you should never accept anything like that). But for that what it is (it's a photography camera in the first place) it's a good film camera.
If moire and aliasing is that a big deal you could spend some extra few hundret dollars to buy the A7 II which has no aliasing and moire (or at least I have never found any).

The codec of the A7 is XAVC S which is 50 Mbit/s in 1080p at 24, 25 an 30 fps as well as at 50 and 60 fps.

December 29, 2016 at 12:26PM

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Eric Halbherr
Director, DP, Editor, Creative Storyteller
1689

Im not much for Sony because of its Bulky menus and their color but i have used said camera and the iterations of it and you can use that camera to shoot anything!!! But as i say time and time again look at youtube demo's of what the camera can do and check out the footage as well.

December 31, 2016 at 9:53PM

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Wentworth Kelly
DP/Colorist/Drone Op
2800

If you are not getting the A7 for full frame reason, I don't see any reason for you to not get a a6300. Probably same price between used A7 and new a6300.
S-log and 4k no moire or aliasing from my knowledge.

January 3, 2017 at 12:14PM

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Keith Kim
Photographer
1510

Go for it!
And forget about the problems. For the price you pay you get a decent camera that for me can achieve great professional results. As long as you know how to shoot and how to direct something how to colour grade etc then a7 can do the trick.

:)

January 3, 2017 at 1:41PM, Edited January 3, 1:40PM

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anthony frank
Director/Editor/Screenwriter
185

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