Exposing with the NEX 5N: don't trust the LCD

Samuel H

Samuel H

Major Contributor
The NEX-5N records to 6-109% IRE, but the LCD screen only shows up to 100% IRE. So, even if you don't see any detail in your highlights, there may be information there: look at the histogram, and use that to set your exposure.

If, instead of doing that, you use your LCD to set your exposure, you'll be wasting approximately one stop of dynamic range.

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After shooting a clip with information in that 100-109% IRE area, two things can happen when you load the footage to your PC:

* If you play back or edit the files in a program that has proper color space management options (like AE), your footage will probably look fine right out of the card

* If your player or editor doesn't have proper color space management options (like Premiere), or if they are not correctly applied by default, then you may see the same kind of false clipping that you saw on the camera's LCD. But a simple levels adjustment will bring that detail back to life: adjust the black input to 16 and the white output to 234, and you'll get truly black shadows and more detail on your highlights.


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Test here:
https://vimeo.com/50077225
 
So Premiere automatically lifts the shadows and crushes (is that the right word?) the highlights because it centers the waveform in the wrong place? Interesting. Does it make a difference if you change the Color Space option on the camera to AdobeRGB instead of sRGB?

Either way, thanks a lot for pointing this out. This simple adjustment of levels really makes a huge improvement in image quality, an improvement which I had been spending forever on the three-way color corrector trying to approximate.
 
Not only that, but the LCD does the same thing: it shows clipping in areas where there's no actual clipping. But I haven't tried a switch between AdobeRGB and sRGB, maybe that will solve it, I'll give it a try.
 
Well, the LCD should also be showing what the camera records, so... I'll give it a try if I get some time this weekend, it should just take me 5 minutes
 
It's annoying sometimes but I like the added buffer the fault gives you. Shoot so it looks almost overexposed on the screen and you know you got nothing blown out. Wondered why I was always able to pull more info from what I thought I had blown out during shooting. Cheers for the info
 
Man, the only LCDs I've ever been able to trust: my T2i; my D7000... and my Marshall!

I don't know why the DSLR LCDs are always so much better than a pro video camera. Yeah, I'll stick a Marshall on a DSLR and eyeball that the LCD is looking good - I think my T2i brightness is down one notch after that. I maybe do that twice a year. My HMC150's LCD is so ugly I can't bear to use it. Horrible thing.
 
did a quick test, really not enough to be sure, but I found no difference with sRGB or aRGB
 
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