View Full Version : Nikon Lens Tests?...Anyone
b e n t o n
09-28-2007, 08:36 PM
I have combed most of the footage, incl. Evan's and
While I marvel at the Red lenses, I wonder about Nikon lens tests.
Am I missing them?
And how is the Magnification ? x1.5%
I work with a Letus 35mm adapter on the Canon XL-H1 which magnifies similarly and I have trouble with getting a good Wide (18mm - 24mm) shot.
David Mullen ASC
09-28-2007, 10:56 PM
I'm guessing that you already understand this... but an 18mm Nikon would have the same image coverage as an 18mm Zeiss or 18mm Cooke or any other 18mm lens... but since the RED camera in 4K mode has a sensor the size of the 35mm movie frame, not the 8-perf 35mm horizontal still camera frame, an 18mm will not be as wide-angle on the RED or a 35mm movie camera (or most DSLR's) as it behaves on a 35mm still camera.
You just have to use shorter focal lengths on average to match what you like to use in 35mm still photography. It's not as bad as the difference in field of view with lenses on a 1/3" DV camera versus a 35mm still camera, just that you'd use an 18mm on the RED camera if you like the look of a 27mm on a 35mm still camera.
Obviously if you plan on using 35mm still camera lenses, you will find it harder to get those shorter focal lengths (below 24mm), as opposed to 35mm cine lenses which naturally come in the common range of focal lengths needed. You may have to look at the cheaper cine lenses on the market to get those shorter focal lengths you need.
09-28-2007, 11:52 PM
I wonder about Nikon lens tests.
Am I missing them?
I don't think there have been any lens tests made (outside of Red) with non-PL mount lenses because no non-PL mount has yet been shipped. "coming soon" was the last I heard.
b e n t o n
09-29-2007, 12:01 AM
Excellent explanation David.
I thought the Nikon mount was being beta tested,
but it's lesser urgency
11-14-2007, 10:06 AM
Having enjoyed the 7.2x magnification factor/FOV crop of a 35mm 300mm Nikon lens on an 1/3" CCD HDV camera for wildlife footage, I realize I will be losing that going to a larger sensor. I realize using the 4k sensor will yield a 1:1.62 FOV using my Nikon lens, but I was wondering if Jim or someone else could offer their input as to what I could expect for a mag. factor if I were to shoot with 2K cropped and the possibility of 2K scaled (if that becomes available at some point). It would be nice to have a higher mag. factor for certain shots of wildlife that is a bit out of reach. Thanks for the valued input.
11-14-2007, 10:41 AM
so with the magnification on the Nikons, how do you calculate for vfx work? If say I shoot with an 18mm Nikon lens that is technically the equivalent to a 27mm lens in a 4K frame, which focal length do I calculate for when I try to matchmove the plate? Also, does anyone know if RED records lens metadata in the r3d files and if so what or how it will calculate for the Nikons?
David Mullen ASC
11-14-2007, 11:57 AM
Again, I think you are just confusing yourself -- and 18mm Nikon on a RED (shooting full sensor) is an 18mm lens and you should make your calculations around that rather than convert everything in your mind to 35mm still camera equivalents.
Saying that an "18mm is a 27mm" is just confusing. An 18mm in 2K windowed mode is still an 18mm, and it's still an 18mm on a Super-8 camera. It stays an 18mm. It just has a narrower view on smaller formats compared to on larger formats.
What sort of calculations are you trying to make?
A 2K crop would have half the horizontal view of 4K full sensor or 2K scaled from 4K.
11-14-2007, 02:39 PM
Okay, I get it now! Obviously i haven't tried it yet but i will be using my RED for making "clean plates" for visual effects purposes. Having all the correct camera data especially Lens information, focal Length, film back, etc is a vital part of 3D matchmoving.
If it is still considered an 18mm on RED (for expample) but has the equivelant of a 27mm in the Full Sensor than you still count it as an 18mm, however, with less coverage on the 4K RED frame than on the DSLR. I get that now.
However, I would be very interested to let a software like Boujou or PFTrack guess what focal length the lens was in a scenario like this and see if it would guesstimate closer to the 18mm or the 27mm focal length because of the "cropped" field of veiw on the RED 4K Full Sensor Frame. Kind of a mute point since you don't want the computer to guess anyhow if you have all the relevant camera data, but nevertheless, i would be curious to find out.
I'm sorry for making you run in circles on this topic, David. Just trying to wrap my brain around it as best as possible.
11-14-2007, 02:44 PM
11-14-2007, 03:01 PM
Boujou or PFTrack need to know the "film back" in order to calculate the Field Of View for any lens. As David has explained, lens mm is a constant, and only the FOV changes depending on the format. Soooo If you have pftrack set to a 35mm Academy film back size it will say 18mm, then if you switch that to say a 35mm still frame size (also called Vistavision or 8perf) it will say it's a 27mm lens.
11-14-2007, 05:54 PM
Thanks Guys for the handy links. This really helps to clear that up for me!