Using Focal Reducer on VV Sensor - get more of an IMAX look

[Nick Vera]

So this is going to be quite an explanation. I recently had a bit of an epiphany in regards to using focal reducers on a Full Frame Sensor.

One night, I was randomly watching a bunch of videos on RED Komodos using focal reducers. (I guess the videos were recommended) I noticed that some FF lenses were vignetting a bit with the reducer on the komodo due to a slight wider field of view coming from the reducer. The reducer was exposing the image circle a bit. So I thought, "if that's the case with the Komodo, maybe with FF sensors I can see more of the vertical field of view within the image circle if I add a focal reducer."

You see one of my requests/wants for RED's next VV sensor is to make it taller so that you can use more of the field of view of FF lenses for tall aspect ratio content. Whether it be 4:3 or the horrific 9:16 content. I would like the sensor to be at least 26mm tall.

So thinking that, I bought Canon's Focal Reducer and slapped it on my VV V-Raptor. (Was going to buy the focal reducer anyway for slow mo content, since 600fps slow motion fps runs at 16mm mode)

Welp there it was, I was seeing more of the image circle at 8K 17:9. I mean I was getting a ton of vignetting as you will see in the images. But, I was getting that vertical field of view. So in all, you can get a larger field of view horizontally and vertically with FF EF glass using the focal reducer. It's also bigger than the Mini LF or Venice area.

The only thing is you would have to crop which would cost a small loss of resolution. But nothing at all to freak about.

If you are framing for an IMAX project (1.43:1) this is a really good digital alternative. Effectively a F1.2 lens becomes a F.9. I'm not counting transmission of light, I'm counting equivalent aperture aesthetic. I believe transmission of light increases to T.8. If you shoot on 15-perf IMAX the fastest IMAX lens which is a T2 gives the same aesthetics of a T.9 on FF.

So this is a benefit of shooting with the regular V-Raptor. You can use a Focal Reducer and effectively increase your field of view, and also get an even more "medium format look" at faster apertures.

P.S. Apologies for the flare right in the middle of the focal reducer shot. That is one minor con to using the focal reducer. You are more susceptible to flaring. I can live with it though and next time I need to lower the eyebrow more.

Cheers!

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[Phil Holland]

Semi-sort of with the Canon Focal Reducer/Speedbooster. It lands at .71X and gets you actually closer to 65mm 5-perf in width, but not quite IMAX 70mm 15-perf.

Here's the experiment I did back in 2017:
https://www.reduser.net/forum/red-cameras/monstro-8k/162309-red-monstro-645-speed-booster-experiment

Long story short, the key thing to do is use larger format glass to avoid any of those coverage issues. In my case that was manly Mamiya, Pentax, or Hasselblad lenses for the 645 format.

I've done weird things since to get to the .58X you need to actually get to the virtual width of 70mm 15-perf, but I would the juice might not be totally worth the squeeze now.

Most interesting, we've been seeing recently 645 glass rehoused in PL mount with integrated focal reducers to gain that stop of light and also increase the FOV. I generally enjoy the lenses as is, but it's certainly a valid way to get a unique look.

 

[Nick Vera]

Definitely remember the test! Always wanted to do that back when I spotted the Monstro sensor in 2015.

I definitely don't mean that the sensor area is close to IMAX with the reducer. Not at all.

I guess my headline was to grab some attention haha

I meant if you wanted to create a similar aesthetic of IMAX at F2, for FF you would need a F0.9 lens. A F1.2 lens with this focal reducer gives you a similar aesthetic. You end up getting a field of view close to the GFX100. At least from what I can see. And the F1.2 lens gives the look of F.9 on the GFX100

The biggest problem is vignetting and corner distortion.

Would love to see a .58x focal reducer to user 6x7 glass. But like you said it might not be worth it

Hope all is well

 

[Phil Holland]

Would love to see a .58x focal reducer to user 6x7 glass. But like you said it might not be worth it

Yep, you can get some of the depth of field characteristics for sure.

I made a .6X a bit ago, but distortion and aberrations were a bit too much for my liking. It's a weird balancing act because a good T1.5 prime wide open gets you very close to much of that without the headache, but what I'd really want is more resolution at that point too. We'll get there. VV is already a huge industry accomplishment for a long while now. Not exactly a lot of 40.96mm and up sensors that roll 8K 120. The readout on the 44mm wide sensos isn't exactly there for professional motion use either, but it will all get sorted as time goes on. For a nimble digital system for reasonably fast glass, likely 65mm 5-perf-ish/645 is going to be the top end of "practical" when that is deemed as such.

 

[Karim D. Ghantous]

I have never seen an IMAX production shot anywhere near wide-open. But of course I do understand what you're trying to achieve.