crop factor question

[Kajito Nagib]

Is the crop factor on a Super 35 like the FS100 or 700 the same as a Canon ASP-C?
For some reason I thought it was closer to a full frame like the 5D
From what I read online the CMOS sensor is "roughly" the same size as an APS-C sensor.

[Alister Chapman]

The FS100 and FS700 sensors are very slightly larger than the Canon APS C sensors, but still quite a bit smaller than full frame 35mm.

[Steve Game]

In addition, the full frame sensors on current SLRs are 3:2 aspect ratio so 16:9 video uses less than 85% of sensor area. So the used sensor areas are about 730sq mm on the 5D and about 315sq mm on the F3/FS100. The APS-C sensors only give 280sq mm for a 16:9 image. So it is better to use a true 16:9 sensor if video is the predominant use of the camera. There will also be better masking and internal reflection control in a sensor mount designed for video.
In addition, a purpose designed sensor will not compromise on resolution, OLPF, (poor moire and artifacts) and pixel skipping, (poor sensitivity for sensor size).

[Sareesh Sudhakaran]

Originally Posted by Kajito Nagib

Is the crop factor on a Super 35 like the FS100 or 700 the same as a Canon ASP-C?
For some reason I thought it was closer to a full frame like the 5D
From what I read online the CMOS sensor is "roughly" the same size as an APS-C sensor.

APS-C was designed to approximate the actual width (24mm) of a 35mm motion picture image. The Epic, C300, FS700/F3/F65 and even the Alexa are all approximately APS-C - to make it sound good they call it Super 35, except that -

Super 35 actually has a 1.33 aspect ratio on 35mm film, but is used to shoot 2.39:1. In that mode, it's vertical size is about 10.4mm - which is less than micro 4/3rd and slightly more than the Blackmagic Camera.

The advantage of using this format is that you get similar DOF characteristics when compared to film.

[Kajito Nagib]

so on the FS700 the focal length of my 50mm lens would be the same as a APS-C sensor 80mm.
The word "Super" before 35 made me think it was full frame or close to it. Thanks everyone:-)

[Kajito Nagib]

BTW very informative blog you have Sareesh.

[Alister Chapman]

Canon use 22.3 x12.5 mm for video on the 7D. The F3/FS100/FS700 are 23.6 x 13.3mm. There's not much in it and your going to find small variations in the FOV between different lenses of supposedly the same focal length anyway. So compared to full frame 35mm (Canon 5D 36 x 20.3mm) the FOV of the FS700 is reduced by 0.7x (so called crop factor of 1.5x).

Just be careful using the term crop factor as if your talking to a cinematographer he/she won't understand you because a 20mm lens is a 20mm lens and from the cinematographers point of view Super 35mm is the norm, not 35mm stills.

[Sareesh Sudhakaran]

Originally Posted by Kajito Nagib

BTW very informative blog you have Sareesh.

Thank you, Kajito!

[Alan Melville]

Guys,

Thanks, you have answered a question I asked some time ago but didn't get a very clear answer to.

I must confess, I found Alisters the clearest as I come from a predominantly stills background.

None the less, I found the other answers interesting.

Al

[Kajito Nagib]

a friend of mine sent me this link which was helpful in me understanding FOV.
AbelCine - Field of View Calculator