Tuesday, June 5, 2012

HS25 Review – Part 17 — EXR DR versus EXR SN versus P Mode – which is the low light champion at 3200ISO?

On the eve of the return of the HS25 to Fuji, I sneak in a formal test of EXR modes against P mode. There are some results out there that suggest that SN mode is significantly less noisy than EXR DR or P mode. I have tested this before and not found that to be the case. Results are invariably equivocal.

So here is the definitive 3200 ISO test of these three modes. Tripod mount, timer release. Light so low that the subjects are exposed at 1/6s at 3200ISO … now that’s low light!

Let’s first look at their web sized presentations (remember that I now use 1000px instead of 800px so there is a lot of benefit for you to click through to the larger one for each.) These are slightly processed to equalize contrast and to set white balance and a bit of extra saturation. A bit of sharpening and NR work too.

EXR DR at DR400

This looks really good when you consider the very low light. The printer in the background has some noise, but it’s very minor. The wool and feather both look great.

EXR SN at DR100

This one was shot at DR100 and the change is obvious. The microcontrast is a bit better, giving an impression of a slightly sharper image. But the reflection of the window on the glass container is blown out completely. The DR400 image held it from doing that and preserved more of the shape. This is why I never shoot SN mode.

The shadows are, for some reason, more open. But they are also more noisy. Very subtle though. You could almost call this a tie, but I don’t like the blown reflection, so the DR400 shot wins.

P Mode at dr400

This looks similar to the two of them, retaining the same level of detail as the EXR DR image did. This is no surprise since the sensor operates just about identically in EXR DR DR400 and P Mode DR400 at M size.

So … the two DR400 modes look fine and they hold highlights better. An easy decision for me, but YMMV.

For my pixel peeping friends … the following crops are straight from the camera with no adjustments at all.

Click image to see the full sized crops in a new window!

What I see is that SN retains a tiny fraction more detail, but has noise and edge integrity issues. Possibly due to the extra contrast from DR100. The white crayon is blown out, losing its dimensionality while it looks best on the P mode and almost as good on EXR DR. Again, I’ve tested this all many times since getting the F70EXR and I always end up in the same place:

P Mode, DR400, M4:3, auto iso 800, 1600 or 3200

Easy peasy.