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Phil vG
09-24-2015, 03:59 AM
I constantly read "this camera is good in low light", "that camera is bad", and so on.
Can someone show me what this is all decided on?
I want to see a bit of video that says, "this camera is 10/10, this camera is 1/10, So I can see what is the best I can hope for if I'm trying to decide for myself. :undecided

The new DVX200 isn't as good in low light as others in the $0 to $8000 price range, so how good could it be (I know that camera isn't out yet, I was just using it for an example)?

arco1
10-25-2015, 06:04 AM
To my knowledge, there is no useful spec for "good in low-light," especially since "good" is an opinion. Some camera manufacturers publish a minimum light spec, but don't tell you how they measure it. Imagers get noisy as the light goes down, but some also exhibit lag or smear, reduced dynamic range, or vertical stripes that can degrade the image. My Sony FX1000 shoots a much better image in low-light than did my old VHS camera with a saticon tube. But the FX1000 is 8-year old technology and is no match for some of the newer Canon or Sony cameras I use, particularly in low-light. Camera technology has advanced so much in recent years that I'd suspect that any camera in your price range should work well in most lighting. Some recently-released cameras are hyped as able to take video in near total darkness.

You may need to better define your intended use for the camera - there's a big difference between a camera used for the low-light of a wedding ceremony lit by candles versus the one that just doesn't require a light truck on your next low-budget feature. Then rent or borrow cameras to test them, or talk to folks using cameras similar to your purposes.

Jim
Colorburst Video


Jim

Ebrahim Saadawi
11-22-2015, 10:48 PM
sing a camera, there's a setting called ''ISO'' or ''Gain'', this setting adjusts the amplification of the imaging sensor to the light (effectively chages the sensitivity if the camera to light). This setting is usually adjustable in values such as 100, 200, 400, 1600, 3200, 12800, 25600, and so on. Going higher being higher exposure and brighter image. 

The problem is, all cameras perform best (have the highest image quality) without light amplification (being left at their standard base ISO), and pushing the amplification higher results in signal ''noise'' appearing in the image. The higher you go, the more noise and worse colours get.

When we judge good/bad in lowlight, it's based upon how the camera's image responds to amplifying the signal and keeping a good image,

Example, two cameras with 100 base ISO, 
-One is set to 400, with complete destruction of the image, having unusable amount of noise and colour deterioration

-The other is set to 400, yet there doesn't seem to appear any noticeable change in image quality. It's still clean and a good image. 

Therefore, camera 2 is better in lowlight. It can see in the dark, push sensitivity of the sensor and still get a good clean image. 

What is this technically determined by? Many factors really.

Starting initially and most importantly with the sensor quality. There are sensor that have a low noise floor and can be pushed, and others with a high noise signal and cannot be pushed much. Second step is how the signal is treated afterwards. Many cameras use Noise Reduction software when you push ISO before giving you the image so that it appears to have similar noise to lower ISO (though NR software can't go too far, but is a factor), 
then there's the compression of the raw data to an video file. Many compression formats have a noise reducing effect by smudging over the raw fine noise and giving a cleaner image. 

Each company has its secrets in how they achieve clean images at high ISOs. 

(Then there's noise reduction software that you can use in post production which helps enormously (Neat Video). But this separate from the camera's lowlight performance, just a tip.)

The best lowlight performing cameras that give excellent images at very high amplification levels are first the Sony A7s, a camera that can litterally see in the dark and can be pushed from 100 ISO to 50.000 ISO and keep a usable image. It's the world'a best lowlight camera but if course is a consumer camera with many downsides. Other lowlight cameras that are close, Canon C100, C300 series, Canon 1Dc, Sony FS7, F5, F55 Varicam35. 

Some cameras that are not very good at being pushed at all: Red Cinema cameras, Arri cameras, Panasonic GH4 falls after 800 ISO (and most micro four thirds cameras), Samsung NX1 falls at 800 ISO also, Blackmagic Cinema cameras (especially the 4K versions) fall apart after 200 ISO, you get the point. 


It's subjective because some people might have lower standards and accept higher image deterioration and vice versa. And some people have higher ISO needs than others where clean 1600 ISO is much more than they want, and other 1600 is not enough, they need clean 3200, 10.000 etc, 

Regarding the dvx200, we hear very good on the lowlight performance area. Supposedly better than the GH4 and gives good images at high ISOs like 3200/5000. But see samples or try before you buy.