physical dimensions for the 4K Exmor Super 35

[Alex Anderson]

I cannot find the physical dimensions for the 4K Exmor Super 35 CMOS in this FS 700 camera. Does anyone know the dimensions? Every camera on the market publishes this information for their sensor.

[Matt Sharp]

It's in the brochure, 23.6 x 13.3mm. http://pro.sony.com/bbsc/assetDownlo...nsion=original

[Alex Anderson]

seems small compared to the Canon full frame 5dmk3 at 36 mm x 24mm

[David Heath]

Originally Posted by Alex Anderson

seems small compared to the Canon full frame 5dmk3 at 36 mm x 24mm

If you use the Canon 5D in 16:9 mode (not 3:2 stills) the usable area is 36x20.25mm - not 36x24mm.

The s35 sensor is nearly 24mm width, which is the distance within 35mm sprocket holes (and the height of full frame for that reason) - the 13.3 mm height follows to give 16:9 aspect ratio. Very similar to 3 perf 35mm film.

[Alex Anderson]

so how do the two realistically compare to each other for shooting in extremely low light conditions? That is what I am mostly concerned about. I was thinking the 5dmk3 with a 50mm f1.2 for some doc work in low light. The slo mo is cool, but not all the time. If I know how the FS 700 does in low light, I might then go for it.

[David Heath]

You'd really have to directly measure them to say.

Simplistically, and all else equal, the bigger the sensor, the more sensitive due to correspondingly bigger photosites. Again, all else equal, if you double sensor size (area) then expect a stop better sensitivity. From that you'd expect the 5D to outperform the FS700 by well over a stop.

Trouble is, all else is not equal.

In the case of the FS700, it's got dimensions designed for video. It's got the right number of photosites if you like. Enough for good video resolution - but no more than necessary.

The 5D has far more, it's primarily designed for stills. Unfortunately, it becomes difficult to then read them all at video frame rates and it's typical for such sensors to ignore a proportion of the sensor total when outputting video. This means that for most DSLR video, the sensitivity is much lower than the simple statement above will predict.

My suspicion is the FS700 will likely have the edge - but you'd have to test to make sure.

[Alex Anderson]

Thanx David. I appreciate your input and taking the time to reply.

Alex

[Bruce Watson]

Originally Posted by Alex Anderson

seems small compared to the Canon full frame 5dmk3 at 36 mm x 24mm

Cinema cameras record on 135 film vertically, while stills cameras use the film horizontally. So a stills camera frame is 36 x 24 mm, and a cinema S35 camera's three perf academy ratio (1.85 : 1) yields a frame that measures 24 x 12.97 mm. Note that they share the 24mm dimension.

Compared to S35 the Sony sensor is a tiny bit shorter horizontally, and a tiny bit taller vertically at 23.6 x 13.3 mm. Close enough to be called S35 for sure.

OTOH, if your question is really about sensitivity, starving sensors of light is a sure path to noisy and washed out images. This was true of film, both cinema and stills cameras. And it's still true in digital sensors. All sensors will be noisy if you starve them of light. Even an Arri Alexa. If you starve them of light, you'll also loose color; hue and saturation will drop resulting in that "washed out" look and you may get some color shifting when you reach the knee of the sensor's sensitivity curve because R, G, and B may not fail at exactly the same place.

Bottom line: low light = low image quality. The only question is, how low will the quality be? And to find that out, you have to do some testing.

[Kieran Steele]

Don't forget your other option with this s35mm camera for low light is to use a metabones speed booster.
Choose your full frame lens a little carefully to go with it, but that will retain the cameras video features (batteries, easy audio, slomo etc) but give you more light.
You will also get a more 5d fov with the sb, and you can even tweak the cinegammas to look 5d if required