Saturday, January 7, 2012

Fuji X10 – Review part 20 – Pro Lowlight Mode for high ISO …

Since the F70EXR, Fuji’s EXR cameras have been able to create low noise images by shooting 4 images in quick succession and blending them to average out the noise. The F70 through F300 shot 4 images at the metered shutter speed, which meant that it was not optimal for hand held photography. On the other hand, the results were pretty magnificent, as you had 4x the exposure, which means about 2 stops better noise.

Of course, this feature is called Pro Lowlight, and I’ll use PLL through the rest of the article. Obviously, all the comparisons here are jpeg mode, since PLL does not shoot RAW anyway.

The F550 and later cameras speed the shutter up dramatically. The cameras are much better for hand held photography, but the results are not quite as dramatic as you might expect. However, you still get enough improvement to choose pro low light when inside a museum etc. Shadows are smoother and noise is finer grained, especially chroma noise where it really counts.

My initial experiment at 3200iso was rather inconclusive. Very dark corner of my desk, shooting the base of the Wacom pen in its holder. Noise is different and PLL looks like it comes out ahead by a bit. But both suck, frankly.

I reset the experiment today and started with a pair of hand held shots at 3200 ISO of some lenses sitting on my printer (for no good reason.)

The P mode shot at 3200 ISO looks like:

And the PLL shot looks like:

Here, the main difference is that the top shot at DR400 actually has a slightly stronger tone curve than the PLL shot. Also, the PLL shot was exposed 1 stop lower. I think Fuji have this really screwed up in the X10, as the F550 does not do this. The shutter is very fast in PLL mode and it’s like the engineers forgot to compensate in the blending algorithm.

Anyway, after equalization, both look nice enough for 3200 ISO on a small sensor. The crops show that there actually is a small advantage, especially in the out of focus areas, where there is clearly a smoother tonality. But it’s close … click through on this one for sure …


I remembered my original tests of PLL mode showing much more dramatic differences … so just for fun, I tested the F70EXR. And the result is staggering … 1600 ISO here as PLL won’t do 3200 on that camera.

Here’s what the PLL image looks like. There is noise (especially prevalent on poor monitors, but some is visible on my calibrated IPS panel too.) But this image is pretty much usable … and this is seriously low light … f/5.6 at 1/4s and 1600iso …

The crops show a spectacular difference!

You can see the difference clearly even at blog size … which is amazing. Remember again, though, that the PLL mode on the earlier EXR cameras shot the metered shutter speed, not a faster shutter speed. So they got a great deal of light into the image.

I like this image for showing the differences quite clearly … so I shot the same subject with the X10 and I finally see a real difference in PLL mode.

It’s not a massive difference, but there is a definite improvement in edge integrity and 3-dimensionality. Look at the lid definition for the nail container to see what I mean. At web sizes, you probably would not see much difference … but of course you should be shooting for the best capture anyway, so PLL mode does make some sense. And the fast shutter speeds improves your odds of a clear shot.

Note, though, that I had to meter 1 stop higher (-1EV on the P mode image and 0EV on the PLL mode image) in order to achieve the same exposure. That is an irritating quirk. The shutter does go 4x as fast it appears, so this is not a big deal. It’s just another issue you need to be aware of to get good exposures with this camera.

One final note. I tried to shoot the F550EXR as well for comparison purposes. The F550 could not get a decent exposure in jpeg and when I added 1 stop and corrected white balance, the whole image turned blue in both cases. Banding was also apparent on the PLL image. The F550 is not a great jpeg camera at really high ISO … the X10 is in another league entirely, as both total sensor area and pixel density are much better.