Frame rate vs. synchro scan shutter

[VeeMan]

Is there a recommended f/stop setting vs. frame rate adjustment. In film camera mode Barry Green mentions at faster frame rates, the user must open up the iris. In his example of shooting at 48 frames per second, he said that the user should open up the iris by 1 f/stop. What about 30 fps?, 60 fps, etc....

Pardon my ignorance, I'm hungry for knowledge and skills and good rules of thumb, etc...

I'm a safety consultant who wants to produce my own line of safety training videos.

Thanks in advance for any help!

Mike

[Barry_Green]

You only have to track the exposure if you're using the film cam mode, 720p mode, and syncro scan shutter all together.

If you are, the amount of exposure compensation you need to make is directly proportional to the frame rate change. 48fps is twice as many frames as 24fps, and needs twice as much exposure (so open up the iris by 1 stop). 30p is 25% more frames than 24p, and would need 25% more exposure (so open up by 1/4 stop), etc.

[VeeMan]

You only have to track the exposure if you're using the film cam mode, 720p mode, and syncro scan shutter all together.

If you are, the amount of exposure compensation you need to make is directly proportional to the frame rate change. 48fps is twice as many frames as 24fps, and needs twice as much exposure (so open up the iris by 1 stop). 30p is 25% more frames than 24p, and would need 25% more exposure (so open up by 1/4 stop), etc.
Thanks Barry.

Your HVX book and HVX Bootcamp series are excellent at any price$$$ I would like to see you put together a DVD that was a sort of a more detailed "how to" type: (1) for dealing with specific shooting situations and what switches, buttons and adjustments need to be made to get the shot. Along with some tips on scene planning. Sort of the 'rules of thumb' or pre-shot planning that comes second nature to you. P.S. I bought a DVD by Victor Milt titled "Director/Cameraman". It was OK. I like your style better. You're very organized and your tips are useful more than you could now.

[VeeMan]

Barry,

I didn't write my first question clearly. Let's try the question again:

If I'm shooting 720/30pN at 30 FPS do I need to open up iris 1/4 stop?

[Barry_Green]

Well, no, 30p @ 30fps = normal exposure. I mean, you'll be getting 1/60th exposure so that will require 1/4 stop more iris than 1/48th shutter would, so I guess you could say the answer was "yes" but only if the question was being asked relative to 24p @ 1/48th. Does that make sense? I fear it doesn't, and that's a bad time to put out a confusing answer, right after you posted a great post to say how useful my stuff is! :)

Interesting idea about another DVD. We're launching a new disc shortly to really explore instruction in an area where I think many of our members don't know quite how to get the best results; that should come out in March. Then we have another big, big disc that'll be coming out a month or two later. So an operations DVD is something we've considered before but didn't know how much interest there might be; something like that could be the next disc on the slate if people want it.

[Noel Evans]

Barry,

I didn't write my first question clearly. Let's try the question again:

If I'm shooting 720/30pN at 30 FPS do I need to open up iris 1/4 stop?

Barrys tired OK :P Ill translate.

1/ Is your project 24p? If so and then you want to add footage shot a 30pn @ 30fps you need to open up the iris by 1/4 stop.

2/ Is your project 30p @ 30fps? Then you wont need to make any adjustment. Just dial in your desired shutter speed and expose with your iris to accommodate correct exposure. Or a bit of both -

The point you are referring to only comes into play when you are over or undercranking for a specific timeline.

[VeeMan]

Your answer is clear!

Look forward to your new instructional DVD's!

P.S.

What specific kind of damage can be done to the HVX if zoom is in "servo" and it is "manually" turned. Will it be something noticeable like the zoom won't work or could it be a subtle thing that a novice wouldn't notice? When I first bought my HVX (and in my own ignorance), I did this once. As far as I can see my zoom works fine. Just wanted your input.

Thanks, Mike

[VeeMan]

Noel,

Thanks for the clarification.

Mike