Waveform and gain doubt at DVinfo.net

Marcus Martell · September 18th, 2014, 09:47 AM

Hola guys, i have a question for you:

how do the waveform work exactly to avoid overexposure? The white stuff shoukd stay between the 2 big rectangles (on a total of four rectangles) right?

Othe question:
the gain should not be less than 400 iso right?
Thank you so much

Kevin McRoberts · September 21st, 2014, 09:55 AM

que tal Marcus

The waveform will show exposure levels across the frame ranging from superb lack to superwhite. In the AF100's WFM, there are a series of dotted horizontal lines and solid horizontal lines... the solid lines represent, from top to bottom, 100%, 50%, and 0% IRE. Ideally white would be at 100% IRE, black at 0% (or usually 7.5%IRE).

Simply enough, just keep the levels from going above 100% to prevent overexposure. Conversely if you want a sold white background and want to be sure you have a solid white background, then adjust exposure and lighting on your background until you have a solid line at 100%. If you want your subject to fall in the ~50% IRE region, then watch for its signature in that range of the WFM.

Here's a video that explains WFMs in general pretty well:

Hope this helps

As to gain, on the AF100 I think 400 is ideal and 800 is still good. Depending on the scene file, 1600 and 2500 are still workable, 3200 is OK but starts to get messy.

Marcus Martell · September 22nd, 2014, 11:46 AM

Thank you kevin!
I really appreciate your post!

September 18th, 2014, 09:47 AM	#1
Marcus Martell Trustee Join Date: Nov 2008 Location: spain Posts: 1,202	Waveform and gain doubt Hola guys, i have a question for you: how do the waveform work exactly to avoid overexposure? The white stuff shoukd stay between the 2 big rectangles (on a total of four rectangles) right? Othe question: the gain should not be less than 400 iso right? Thank you so much

September 21st, 2014, 09:55 AM	#2
Kevin McRoberts Major Player Join Date: Jun 2008 Location: Charlottesville, VA Posts: 700	Re: Waveform and gain doubt que tal Marcus The waveform will show exposure levels across the frame ranging from superb lack to superwhite. In the AF100's WFM, there are a series of dotted horizontal lines and solid horizontal lines... the solid lines represent, from top to bottom, 100%, 50%, and 0% IRE. Ideally white would be at 100% IRE, black at 0% (or usually 7.5%IRE). Simply enough, just keep the levels from going above 100% to prevent overexposure. Conversely if you want a sold white background and want to be sure you have a solid white background, then adjust exposure and lighting on your background until you have a solid line at 100%. If you want your subject to fall in the ~50% IRE region, then watch for its signature in that range of the WFM. Here's a video that explains WFMs in general pretty well: How To Use Waveform On A Monitor - YouTube Hope this helps As to gain, on the AF100 I think 400 is ideal and 800 is still good. Depending on the scene file, 1600 and 2500 are still workable, 3200 is OK but starts to get messy. __________________ Freelance pudgy bearded lighting camera operator www.mcbob.tv

September 22nd, 2014, 11:46 AM	#3
Marcus Martell Trustee Join Date: Nov 2008 Location: spain Posts: 1,202	Re: Waveform and gain doubt Thank you kevin! I really appreciate your post!