Working at 2k Vs Field of view for 35mm lenses
Posted 08 September 2008 - 09:02 AM
I was going tru some tests with a RED ONE build 15. I was testing High Speed of camera to get to know how it looked.
So camera was set at 60 fps with the equivalent of a 45 deg shutter on. the lens that I had at hand was a 18mm ( 35mm prime lens ), but somewhat it "feeled and looked" a little bit Narrower field of view that would normally do on a 35mm camera, I was so into testing the high speed of the camera that I didnt paid too much attention to this, now Im still wondering if at 2k and in a 2:1 aspect ratio of the sensor ( choosed from the menu of the camera ) would it be the
same as using 35mm lenses on a super 16 camera? that was the way it looked on the RED monitor, is it this the way it works on the RED? so my question here is that 1. If set to 4k on proy preferences will the 35mm lenses have the same field of view as they should 2. If I work at 2k will the 35mm lenses loose their original field of view or have it transformed like if it was putting them on a sup 16 camera? so they become narrower?
Another funny issue is that I was doing a water pouring at 60fps on a glass coup against black velvet and over black velvet, when I set the camera to an equivalent shutter angle of 11 degrees, suddenly part of the image turned sort of gold / brownish. Lightning was a 1200 par HMI with magnetic ballast ( that's why I choose 60 fps ) Diffussion frame with 216 and a 6x6 Bounce board on the other side, so I cant really see why reflections on the cup turned out brownish / gold. quite strange. Cam exposure set to 320 ASA so whas my meter but always checked on the Illegal color setting on the onboard monitor, exposure was very much consistant with the light meter.
Cheers and many thanks for any clues on this subject.
Posted 08 September 2008 - 09:25 AM
If you close your shutter angle too far down, your exposure time narrows to a point where a unit such as a magnetic ballast HMI will show numerous artifacts including the color cast you describe.
Posted 08 September 2008 - 09:32 AM
When shooting high speed I was hoping/planning on using the full s16 frame at 2k. Am I wrong?
Please explain to me the ins and outs of shooting s16 on the RED. I would really appreciate it as I am confused.
Posted 08 September 2008 - 09:39 AM
Posted 08 September 2008 - 10:09 AM
I could shoot full frame 4k and crop down but I would rather shoot full frame s16 at 2k.
Posted 08 September 2008 - 01:38 PM
Posted 08 September 2008 - 07:18 PM
Posted 09 September 2008 - 03:26 AM
Can anyone tell me the actual FOV loss relative to s16 of shooting 2k on windowed RED?
I understand that a B4 video lense covers the RED windowed chip with slight magnification. A B4 lens just about covers a s16 gate. If your saying a B4 lens has slight magnification relative to video on a windowed RED, your saying that a windowed RED chip is SMALLER than 2/3rd inch. So will have CONSIDERABLE magnification relative to s16
Edited by thomas-english, 09 September 2008 - 03:27 AM.
Posted 09 September 2008 - 11:46 AM
A B4 lens projection is smaller than 16mm. It needs to be magnified to fit on either the RED One or the SI-2K.