Rack aperture?

[john jeffreys]

Currently planning a long tracking shot in which the main character parks his car, gets out and walks all the way across the lot, into a hotel, through the first floor and into an elevator at the end of the hall. We are going to have to somehow compensate for the huge light difference from the parking lot (night, 3am) to the lobby. Someone told me that in the opening shot of Boogie Nights, they did the indoor/outdoor transition by racking aperture; how would I go about this? Just have a second follow focus attached to the aperture ring, right? Is there an easier way that I am not aware of?

 

[Mikael Lubtchansky]

If you have an Epic, you can try this :

set your aperture for the darkest part of the sequence (ext night), then calculate the aperture closure needed for indoor (brighter) segment and dial that in the HDRx.

You'll have a fully open A track and a darker X track that you can transition to in the edit room... I tried it and it works quite well (was going dark indoor to bright outdoor in my case). you'll just end up with sharper images (shorter exposure) on the X track but it shouldn't be a problem unless you have heavy motion blur in the first part...

If you have a scarlet or prefer the old way then yes a rack aperture is often done on camera to compensate for exposure differences within a shot

 

[Patrick Tresch]

I would nt do it with the HDRX trick because of motion blur. Changing the aperture is the cleanest way of doing it.
Even the operator can do the change on the lens. It s much lighter for handheld Work.

Pat.

 

[Brad Webb]

If you have the side handle and a motorized lens you can do iris racks by simply selecting the aperture and moving the click wheel. If you have a dumb lens then just change the aperture by hand on the lens. The AC or camera operator can usually do this.

Another solution is to light the actor to an acceptable range outside and have the light follow him until you get to the interior. Easiest way to do this is hang a china ball from a poll and walk in front of the actor.

EDIT: you can also use the REDMOTE to change the aperture. Although I'm not 100% you can change the aperture while rolling with the REDMOTE.

 

[Phil Holland]

If you are looking for a smooth transition between aperture values it's pretty easy to do with a dumb lens and an additional follow focus or motorized electric focus device. Some PL lenses have gears on the aperture. If not you can rig one using a plastic focus gear. Just make marks just like you're pulling focus.

*I can confirm you can change electronic aperture values while rolling on Epic and Scarlet.

 

[Matthew Bennett]

I really like old school manual aperture racks, I find them pretty charming.

There's a great shot (I think the very first shot) of Jackie Brown, where Pam Grier is walking through an airport, and they rack aperture down and up again every time she passes by a window. Great shot...

 

[Johnny Friday]

....and then there is selecting a mid range aperture and keyframing in post.

 

[john jeffreys]

Ok, cool. Thank you all for the wonderful advice. I think we are just going to change the aperture by hand once we enter the building. We might also try a take with the china ball idea that Brad suggested.