8mm Century Lens

[corrientearriba]

Im shooting at 2K and was about to try a PL Century 8mm lens, then I realized that at 1.85:1, I have a viñete on both sides of the frame. Is this because at 2K in a 1.85:1 format the 35mm Red sensor works with a smaller area, and therefore wide angles lenses like 8mm, 10mmm have this problem? Does 4K solve this problem? Is there any other suggestion when using these kind of wide angles lenses? Thanks!!

[Guidofilippi]

I think that´s a 16mm lens, it doesn´t cover the super 16 area. So it slightly vignettes at the corners at 2k. Apart from that... your reasoning is sort of upside down!
Cheers,
Guido

[corrientearriba]

Thanks guido! Can you please be more specific on why my reasoning is up side down? Perhaps it is a 16mm lens, thats exactly the reason I dont get why at 1.85:1 these kind of lenses have a viñete, and if at 4k this problem is solved.
Thanks again, cheers!!

[Jeff Kilgroe]

He was saying that your reasoning is upside down because at 4K this "problem" is not solved. If you shoot at 4K with that lens, you will not just see a vignette, you will most likely see most of the image circle, surrounded by black space. The RED One sensor is close to Super-35 size when you shoot 4K. When you shoot 2K, it uses a smaller area of that sensor, cropped out of the middle.

The problem is the lens you are using is most likely designed for 16mm formats. So it is not going to cover the entire 2K image area on the RED One, which is essentially Super-16 in size. Wide angle lenses have relatively smaller image circles or coverage areas, compared to lenses with longer focal lengths, so you start to see the vignette on the wide end.

[Peter Lyons Collister, ASC]

I believe that Century 8mm is a re-housed Nikkor 8mm for the stills market. On a still camera (24mmX36mm) is creates a circular image surrounded by a vignette of black.

This lense has been re-housed by various rental houses and also Panavision. It is often used for the POV from a security door peephole. Also it was used by Stanley Donen in the film "The Little Prince"(1974) to shoot an entire scene on an imaginary planet. Even on a 35mm cinema sized format it vignettes quite heavily.

More information than you wanted I imagine.

[corrientearriba]

Thanks for the explanation on the vignete issue.
If the red sensor size is Super 35mm at 4K and Super 16mm at 2K, what size could we compare it to if shooting at 3K?
Am I correct to assure that If the Century 8mm lens was built for a 35mm format, it would still have the vignete on both 2K and 4K?
Thanks again!

[corrientearriba]

Yes, I believe the lens is a re-housed Nikkor 8mm. Thats exactly why I was trying to learn the differences when using a variety of lenses, not only the ones built for 35mm cameras, also the ones built for stills photography.

[Jeff Kilgroe]

If this is indeed the century converted 8mm Nikkor fisheye, it does fall just short of covering the S35 area at 1.85:1. You'll see the vignette fall-off and black in the corners. I've shot with that lens a couple times. In my post above, I was under the impression you were using an 8mm rectilinear lens intended for 16mm.

3K on the RED One isn't really analogous to any standard size. It's just half-way between the 2K and 4K frame sizes. 3K 16:9 is 3072x1728 pixels and has a sensor image area of 16.59mm x 9.33mm.

[corrientearriba]

When you shoot 2K what is the size that is cropped out of the sensor, and the same question when shooting at 4K?

[Jeff Kilgroe]

Active sensor area on the RED One, which includes the "look-around" area is 4520x2540, which equates to 24.4mm x 13.72mm. The actual recordable modes are smaller than that, these are all stickied around the forums in various places, but here are the RED One mode sizes.

4.5K & 4K modes...
4.5K = 4480x1920 = 24.19mm x 10.37mm
16:9 = 4096x2304 = 22.12mm x 12.44mm
2:1 = 4096x2048 = 22.12mm x 11.06mm

3K mode sizes...
16:9 = 3072x1728 = 16.59mm x 9.33mm
2:1 = 3072x1536 = 16.59mm x 8.29mm

2K mode sizes...
16:9 = 2048x1152 = 11.06mm x 6.22mm
2:1 = 2048x1024 = 11.06mm x 5.53mm

[Ben Graham]

I have an Optex 8mm which is great for 2K on RED with no vignetting. Super sharp and fast.

Visual Products has one for sale:
http://www.visualproducts.com/storeProductDetail03.asp?productID=640&Cat=8&Cat2=15&Cat3=16