View Full Version : crop factor nikon lens
gerald stahlmann
09-07-2008, 08:20 PM
Hey guys... just wanted to know wat is the crop factor of the nikon lens on the red. I noticed that say a 24mm lens looks more like a 35mm. Why is that? I snt the red suppose to be a full frame camera?
Matt Uhry
09-07-2008, 08:40 PM
Hi Gerald,
Welcome to Red User.
It will ultimately be easier if you don't think in terms of focal length multipliers and instead think in terms of angle of view for different capture formats.
The Red in 4k mode has a capture area roughly like a APS-C digital SLR. It's also pretty close to Academy 1.85 if you are used to 35mm motion picture formats.
A 50mm lens is always a 50mm lens and the physics of what it will do in a given situation remain the same regardless of the format you use it on.
This is why focal length multipliers lead to confusion and ultimately a sad, painful and miserable death.
It's 1.6x
Matt Uhry
www.mattuhry.com
Mark Crabtree
09-07-2008, 08:49 PM
The full frame motion picture standard super 35mm sized sensor is a little smaller than a full frame digital 35mm SLR sensor. Super 35 motion picture frame is closer in size to a digital still APS sensor which has a crop factor of 1.6. So you can more closely relate the Red's image magnification with an APS camera like the Canon 40D.
gerald stahlmann
09-08-2008, 03:53 PM
Thanks guys for your response...so which means if i were to use dx lenses wit doug's dx mount for the red, i wont be getting a 1.6x crop on the red?
Paris Remillard
09-08-2008, 04:13 PM
Thanks guys for your response...so which means if i were to use dx lenses wit doug's dx mount for the red, i wont be getting a 1.6x crop on the red?
It depends on what you are basing the crop on. If a 24x36mm full frame dSLR sensor is the base, then the 22/24(ish)mm x 13/18(ish)mm sensor of the Red or an APS-C sized dSLR will have a 1.6x crop in field of view in comparison to the full frame dSLR.
Remember that 35mm film moves through a motion picture camera vertically, whereas it moves through a still camera horizontally. So, the motion picture 35mm frame is only half (or I suppose about 1.4/1.6x smaller measured diagonally)the size (24x18mm approx.) of stills 35mm (24x36mm). So the Red sensor is full frame for motion picture 35mm. If the motion picture standard is your basis for formulating a crop factor, then there is no crop. The FOV is the same on the Red as it would be on Motion picture 35mm
Look at the diagram on the right hand side of this page :
http://www.red.com/cameras/technology
Think of a particular focal length being a circle that is just larger than the green Full frame dSLR image at the top. Now if you move to a smaller sensor like the APS sized dSLRs or the Red, which are represented below, the circle that covered the full frame above is still exactly the same, as it is the same lens and same focal length, but since the sensor is smaller, you are just seeing a smaller portion cropped out of the full image circle.
If the original question was just whether you would be getting essentially the same FOV on the Red with a Nikon DX lens as you would on a smaller sensored DX camera, then the answer is yes, and I just explained more than I needed to : )
Sanjin Jukic
09-08-2008, 04:39 PM
Ken Rockwell-Crop factor-Canon 1.6x Cameras>>> (http://www.kenrockwell.com/canon/1-6x.htm)
gerald stahlmann
09-08-2008, 11:16 PM
Thanks a lot for the info guys.
Cheers
Gerald
Ariel Weiss
09-09-2008, 03:55 AM
dx and full frame lenses will give you the exactly same image if it has the same focal lenth and used on the same camera (like red here). just in cases of very long zoom and short prime (the phisycal lengh of the lens itself) there could be a defference between identycal focal lenths.