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How to test the dynamic range of a camera...


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#1 Evan Richards

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Posted 12 June 2017 - 12:41 PM

So lets say I'm an individual who doesn't have much of a budget (I am and I don't) for expensive testing equiptment etc.

 

Is there a fairly accurate way to measure the dynamic range of a camera? I did a little googling and wasn't too satisfied with the answers.

I feel like there might be some way to do it by exposing a gray card properly and then exposing up and down to see when it blows out or loses detail...but I'm no expert at all.

It SEEMS like there might be some kind of low tech solution like that and I just want to make sure I'm not missing it.

 

 

 

Any suggestions?


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#2 Michael Rodin

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Posted 12 June 2017 - 01:39 PM

You got it right - you do an over/under exposure test on a neutral gray object. Better use a grayscale chip chart though.


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#3 David Mullen ASC

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Posted 12 June 2017 - 02:01 PM

Put a white card and a black card on each side of an 18% gray card -- under and overexpose in whatever increments you want until you can't see a difference between the white and gray card at the overexposed end and between the gray and black card at the underexposed end. Make sure you shoot at whatever is the widest dynamic range recording format the camera offers (raw, log, cine gamma, hypergamma, etc.) but also test it in the narrower Rec.709 display gamma range just for comparison.
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#4 Evan Richards

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Posted 12 June 2017 - 02:07 PM

Put a white card and a black card on each side of an 18% gray card -- under and overexpose in whatever increments you want until you can't see a difference between the white and gray card at the overexposed end and between the gray and black card at the underexposed end. Make sure you shoot at whatever is the widest dynamic range recording format the camera offers (raw, log, cine gamma, hypergamma, etc.) but also test it in the narrower Rec.709 display gamma range just for comparison.

Awesome! Thanks for you expertise David!

Will give it a shot.

 

Cheers


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#5 Evan Richards

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Posted 12 June 2017 - 02:18 PM

You got it right - you do an over/under exposure test on a neutral gray object. Better use a grayscale chip chart though.

That's a good thought.

Will give it a shot! 

Thanks!


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#6 Evan Richards

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Posted 12 June 2017 - 04:28 PM

Put a white card and a black card on each side of an 18% gray card -- under and overexpose in whatever increments you want until you can't see a difference between the white and gray card at the overexposed end and between the gray and black card at the underexposed end. Make sure you shoot at whatever is the widest dynamic range recording format the camera offers (raw, log, cine gamma, hypergamma, etc.) but also test it in the narrower Rec.709 display gamma range just for comparison.

And I suppose the more flatly and evenly your cards are lit the more accurate your test will be.


Edited by Evan Richards, 12 June 2017 - 04:28 PM.

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#7 David Mullen ASC

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Posted 12 June 2017 - 05:33 PM

The black card should be as black as possible, some people create a recessed box lined in black velvet.
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#8 John E Clark

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Posted 13 June 2017 - 11:30 AM

I use a combination of 18% grey card, Black 'velvety' cloth, white lacy cloth, and a color chart.

 

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