FZ200 at 1600 ISO



I set out to master the FZ200 at 1600 ISO, since they say it can't be done. I haven't quite achieved my goal, but I've mede some observations en-route that I'd like to share.

My first images were shot with the camera right out of the box. I set the dial to "P", selected 1600ISO, and started shooting. The first thing that I noticed was that at normal sizes (ie filling my 60cm diagonal monitor) there was very little noise and the pictures looked crisp and sharp.

So what was the problem? Enlarging a normal 1600ISO image to poster size, putting it on the wall, and viewing it from the recliner will not show any noise. Period.

But, pixel peeping at 1:1 magnification revealed that there was plenty of noise and image degradation because of various processing artifacts. So I decided to investigate.

It soon became obvious that the image quality (IQ) of my shots depended on the subject. Dark, even areas looked noisier than more complex scenes, and fir trees didn't look good at all. Rather like they were shot on 400ASA B&W film back in the good old days.

As I mentioned, I started shooting with the camera on its default settings. When magnified I saw that the noise was quite aggressive in nature, i.e. it was not "pure" white pixel noise, but made a complex random pattern involving large groups of pixels. This type of noise is more visible than pure noise and fools many noise reduction algorithms into thinking that it's fine detail that shouldn't be touched.

So how to minimize and eliminate it?

I started to experiment. I found some dependencies between the various settings. My findings can be summarized like this:

The higher the contrast, sharpness, and saturation and the darker the subject, the more objectionable the noise intrudes into the picture, and the harder it is to get rid of in PP.

The first practical application of my findings was to expose the picture so that the areas of interest were well exposed. To my surprise, metering with a 18% gray card showed that the FZ200 often chooses to expose for a darker scene than the 18% standard dictates. So, goodbye my 100ISO habit of using -1/3 stop exposure compensation as a starting point, and of using spot or centre weighted metering. Instead, I had to develop a habit of exposing using the histogram.

First you have to enable the on-screen histogram. Then the trick is to juggle the exposure compensation dial so that the histogram is just touching the right hand edge. Low lit scenes are often of high contrast, and this technique will result in car headlights, street lighting and other bright objects being off the scale. But they usually don't contain any detail worth preserving anyway, so it's usually OK. This will also result in a lighter looking image than usual, but it will maximize the noise performance of the image sensor. The mood of the picture will suffer, night shots looking like they were shot in the afternoon, but that is easily corrected by darkening the scene during PP.

Secondly, I found that the standard camera settings could be improved upon to get that last drop of performance from the sensor. Selecting the "Natural" scene mode reduces contrast and saturation somewhat, and tweaking this mode further by setting both sharpness and noise reduction to -2 produced pictures that lent themselves the best to sharpening and noise removal during PP. To my surprise, setting both to +2 came in second, whereas unbalanced settings were the worst, so that setting NR to -2 and Sharpening to +2 or the other way around, produced the most noise.

If you don't want to do any PP, the best resolution and noise performance is had by setting both Sharpness and Noise Reduction to their +2 setting. But be warned, even though this setting produces clean images at all normal enlargements, this setting also changes the noise in a way that's almost impossible to remove in PP without artifacts – at least if you view the image at 200%.

A final word on shooting RAW at high ISOs. The dynamic range of the sensor is only just 8 bit at these ISO settings, so there is precious little extra highlight or shadow detail to be had from a RAW file. Secondly, the noise performance is likely to be worse without some serious tweaking in something other than Silky Pix.