GH2 Question About Low Light Shooting and Histogram

Noah Truth

Noah Truth

Active member
So I shot an event last week in a theater where there was minimal light other than stage lighting. My f-stop was wide open (1.7) the entire time and I was varying the iso between 160-400, shooting at 50fps. I noticed the Histogram would blink consistently when the iso was 320 or below. However, when I played back the footage in Premiere, the exposure seemed fine. There were few to no underexposed areas that I was aware of.

I was using Flow Motion, shooting in 24p mode at 50Mbps.

My question is, how conscientious are you guys of your histogram in low light? Do you find that you can usually get away with lower iso's or push an underexposed shot w/ little to no image loss as long as you're using higher bit rates?

Thanks.
 
Last edited:
I never use the histogram. Mostly because I feel the waveform is a far more useful tool for exposure, but the GH2 doesn't have one.

However, I have noticed that I can push the gamma up to 1.5 in PP without any objectionable noise introduced. I'm amazed at how well this footage holds up. (AN Cluster v7, DREWnet 12/15 Soft)
 
With the GH2, I'm always watching the histogram but since it's a DSLR I take it with a grain of salt and no, I don;t have any issues shooting with low ISO in low light. Here's a video gram from footage I shot using 400ISO and a 25mm 1.4 prime and an 88mb/s hack... Has virtually no noise!

Decoding_Screen17.jpg

Of course, with the new SmallHD DP7, you'll have a waveform and other great software tools built into the monitor which will totally change the game for exposing and shooting on DSLRs.
 
I think the histogram is a usable tool but the GH3 should have waveform of course. Also try shooting in 1/40, some say it looks better than 1/50.
 
Last edited:
Noah Truth said:
My question is, how conscientious are you guys of your histogram in low light?
Click to expand...

The histogram is NOT an exposure meter, nor even an exposure guide (unless one knows how to interpret it). The histogram simply shows the distribution of light and dark image tones (and their intensity) over about a 5 stop range. The histogram of a still (or video) image shot in low light will reflect the fact that the image tones will be mostly dark so the "spikes" will likely be "crowding" the left side of the "graph".

Snow covered mountains or scenery will have a histogram with most of the spikes crowding the right.

There is no "right" or "wrong" histogram, it is what it is for each situation. I leave it on so I have a running visual indication of where my image tones for each situation happen to "fall" and what the general distribution over the range of the "graph" is. But for exposure in low light, I depend more on what the image looks like in the viewfinder. The histogram will help me to understand what I'm seeing relative to exposure.
 
Jim Simon said:
You mean shutter speed?
Click to expand...

I should stay away from the mushrooms.... yes I meant shutter speed, 1/40s instead of 1/50s. It will give you 20% more exposure and some say it looks more like film than 1/50s. Honestly in emergency situations I've even been shooting with 1/25s and didn't look that bad at all.
 
Bruce Foreman said:
The histogram is NOT an exposure meter, nor even an exposure guide (unless one knows how to interpret it). The histogram simply shows the distribution of light and dark image tones (and their intensity) over about a 5 stop range. The histogram of a still (or video) image shot in low light will reflect the fact that the image tones will be mostly dark so the "spikes" will likely be "crowding" the left side of the "graph".
Click to expand...

When setting exposure so that you don't see clipping in the blacks or whites and also not showing gaps at the left or right side, at least the material won't be under- or overexposed and takes advantage of the full color space bandwidth and is easy to correct by grading. What is very hard to determine when using a histogram is exposure of an image in which you would let the whites clip in a certain area on purpose, for example a light source or a window, etc but that can be solved by first framing the image without showing the light source/window, setting exposure, and then frame the image properly. But normally a wrongly exposed image is not hard to recognize by looking at a histogram but I agree that it takes a lot of practicing. Of course a waveform is much, much better.
 
Bruce Foreman said:
There is no "right" or "wrong" histogram, it is what it is for each situation. I leave it on so I have a running visual indication of where my image tones for each situation happen to "fall" and what the general distribution over the range of the "graph" is. But for exposure in low light, I depend more on what the image looks like in the viewfinder. The histogram will help me to understand what I'm seeing relative to exposure.
Click to expand...

Yeah. I've pretty much defaulted to the viewfinder when assessing exposure and it seems to give a fairly accurate representation. Thanks for your suggestion.
 
RieniO said:
etc but that can be solved by first framing the image without showing the light source/window, setting exposure, and then frame the image properly. But normally a wrongly exposed image is not hard to recognize by looking at a histogram but I agree that it takes a lot of practicing. Of course a waveform is much, much better.
Click to expand...

Pardon my ignorance, but what exactly do you mean by framing?
 
You must log in or register to reply here.
Back
Top