General RED advice for new user doing slow motion shoot tomorrow!

[James Bayliss-Smith]

Hi all. So I'm new to red cameras but I'm using 4 of them (epic's) to film something quite specific on Friday. Basically I am filming a model skyscraper undergoing earthquake testing. The model is 7m high and I have been tasked by the client to film it in slow-motion for a technical analysis from each side. I will aim to be shooting at 120 fps to be played back at 24p (I think). I have hired a lighting guy to light it very well with big lights (that's all I know I'm a bit out of my depth here) so I can shoot at a high shutter speed as required by these high frame rates. I've been told the lights are switchable between 60hz and 50hz so I'm planning to go with 60hz to eliminate any strobing in the final image, I'm going to test it all tonight. To maintain a 180 degree shutter I will shoot at 1/240th of a second shutter assuming I have enough light.


I'm looking for general advice but I have a couple of specific questions

Will strobing (if there is any) show up on the standard Red monitor or will I have to ingest and play back on a computer to check this?

Do my assumptions above make sense?

What Red codec do I need to use or should use?

What will happen if I shoot 120th shutter, that is 360 degrees? Will I get loads go motion blur?

Any other general comments and advice?

 

[Hal Long]

Hi all. So I'm new to red cameras but I'm using 4 of them (epic's) to film something quite specific on Friday. Basically I am filming a model skyscraper undergoing earthquake testing. The model is 7m high and I have been tasked by the client to film it in slow-motion for a technical analysis from each side. I will aim to be shooting at 120 fps to be played back at 24p (I think). I have hired a lighting guy to light it very well with big lights (that's all I know I'm a bit out of my depth here) so I can shoot at a high shutter speed as required by these high frame rates. I've been told the lights are switchable between 60hz and 50hz so I'm planning to go with 60hz to eliminate any strobing in the final image, I'm going to test it all tonight. To maintain a 180 degree shutter I will shoot at 1/240th of a second shutter assuming I have enough light.

Hi, If you have an LCD monitor there you should be able to see strobing okay, but your gaffer should be able to help you out here. Fluorescent and HMI's can strobe at various frame rates, tungsten lights should not. At 120fps you should be fine. Red actually has a cool calculator on their website to help you with this. It will tell you safe frame rates and shutter angles.

http://www.red.com/tools/flicker-free-video

See below for other answers.

I'm looking for general advice but I have a couple of specific questions

Will strobing (if there is any) show up on the standard Red monitor or will I have to ingest and play back on a computer to check this?

Do my assumptions above make sense?

Yes.

What Red codec do I need to use or should use?

The highest you can, the camera will adjust record quality as frame rate goes up.

What will happen if I shoot 120th shutter, that is 360 degrees? Will I get loads go motion blur?

No. You're still @ 120th/sec. You could skinny the shutter a bit if you want it crisper.

Any other general comments and advice?

See my comments in the body of your text above.

Do a test of something else falling and replay to make sure it's as expected. 120 fps is pretty fast but if it's a small object collapsing you may want a higher rate to have it play out longer.

Good luck!

 

[Paul Russell]

If you're going to light with tungsten, put an 80C filter over the lens so that your blues aren't noisy.

DC light sources or HMIs are best. Mains powered flourescents will flicker a lot above 100fps. At 120fps you will need four stops more light than at 29.97 fps.

 

[Marc Wielage]

Shoot tests first!

 

[James Bayliss-Smith]

​Thanks for all your help and advice. A few more questions (I start shooting in 8 hours!)

Is it wise to reset the camera settings in the morning to factory defaults, could this cause me any problems?


Do I need to do black shading specifically at the 120fps 1/240th settings I plan to use? (I understand this has something to do with temperature) it will be very cold ( 3 degrees ) in the morning when I do this but throughout the day will get warmer will this effect the black shading. I don't really understand this


As this is for a technical analysis of a earthquake test of a skyscraper I've decided to place the cameras on their sides to make full use of the resolution otherwise the skyscrapers just take up the middle of the landscape orientation. I will then rotate them in post.


I can shoot 10:1 down to 18:1 red codec. Transferring times will be an issue as I have 4 cameras shooting 120fps 1/240th shutter and only one laptop so I'd rather shoot at nearer to 18:1 will this noticeably effect image quality?


I went to the site earlier and the Gaffers done a great job, shed loads of light and no flicker at 120fps with 25p time base. I don't even need to have the aperture wide open. Should I expose for the lowest ISO possible? I know I can change this afterwards but if I'm compromising on data rate using 18:1 then it'd be good to have minimal noise?


Given that there is loads of light, is it worth trying to shoot at a quicker shutter than 1/240th which I believe is 180degrees (at 120fps). I'd like to minimise motion blur as this is for technical analysis for an engineering company but do I need to go further than 1/240th?


Thanks

 

[Hal Long]

James, If you've prepped the camera before the shoot, you shouldn't need to reset to defaults. If you've never touched the camera until now, you should go through the menus. I'm not a fan of full resets right before you plan to shoot. You're stuck if a problem comes up.

I don't believe ambient temperature affects black shading. You might be thinking of color temp. Yes, you should black balance. Put the body cap on the camera and do the balance. Red has instructions.

Shoot the highest quality you can. You can't get the detail back later.

Yes, go for a narrower shutter and you'll get a cleaner image. You can always add motion blur in post.

Have fun!

H