-
OT: Problem WIth a Fisheye Lens
I posted this in the Cinematography forum but would like to hear feedback from those in the FCP forum which I frequent.
A company I’m working for produced a special video project for a client. The client owns some specialized projection system that has fisheye lens and a dome-type convex projection screen. It’s like a mini planetarium or IMAX. It’s meant for trade shows.
So to shoot footage for it, it requires a fisheye lens on the camera as well. They shot footage using a Panasonic Varicam with a fisheye lens. The lens was meant for a film camera, so they used some adapter for it.
When I first looked at footage, I saw this horrific textured layer covering the whole image. Below is a still of it and you can clearly see the problem in the sky
You may want to download the image to see it full size.
The worst part is that the layer is not static. It continuously rotates in a circle.
The vidoeographer did not catch the problem I guess because it rotates so fast it shows up as a a mild flicker on his monitor. But the overall result is devastating. The detail is non-existent – it looks like it was shot on a cellphone camera.
We think the lens adapter may have been defective but don’t really know. I’ve been an editor for over a decade and have never seen anything like this.
Can anyone who understands optics and cameras explain how this could have happened? Thanks! -
4 Replies
-
I’ve seen this before – its a problem with the adapter.
I’m not a cameraman, but this is how I understand it – 35mm adapters have a spinning ground glass component to them. The lens that attaches directly to the video camera must be properly focused so that the ground glass becomes invisible.
If not, it totally ruins the shot. I played around with blurring and resharpening, different color channels, with color correction, nothing works. You’ll have to live with it, or reshoot it.
-
[Bill Dewald] “35mm adapters have a spinning ground glass component to them.”
You’re exactly right. Most of them you can turn the spinning on or off to save batteries. It looks like they forgot to spin the glass before the shot.
Jeremy
-
Thanks guys. This is a huge help.
Sean
-
No worries. I hope you can get it sorted out.
Jeremy
Reply to this Discussion! Login or Sign Up