And so we begin the formal tests. This is the classic ISO ladder late in the evening by the very old and orange halogen lights I keep in this room, blasting their light onto the ceiling from 15 feet away. I tried to color correct the images, but yet one more time I find that the reds become violently ill with blue channel poisoning, so I’m just going to show it as the camera saw it. Which is not that bad, by the way.
Considering the difficulty I had at full zoom, this performance is a little better. I shot in manual mode with the aperture stopped down a single tick so as to hit what will be close to the sweet spot for sharpness. All the tone and sharpness controls are on low, as is the noise reduction. I’ve learned that lesson early.
Here is what the test image looks like straight out of the camera (SOOC) – 3200iso M4:3 DR400:
The image is really quite nice, when you consider the ISO. A bit washed out, but remember that I set DR400 and I turned all the tone stuff down. The point is that this is a good capture for processing. Minimal “bruising” of the pixels.
And here it is same image tweaked in ACR7 / CS6:
YMMV of course, but I much prefer that image. More punch and a stronger impression of detail. Very nice.
The crops are SOOC at all ISOs with the L4:3 image downsized to match the M4:3 image. This is how most people will use them anyway.
Click to expand image. Remember to click again to expand in browser.
You really need to expand that image to see anything
So what do we see in the crops? Well, at 100 ISO the contrast does help the L image a bit. There is more detail at the wide band, which helps the wool a bit. The feather has a bit more detail in the veins. So at 100 ISO I would vote for the L image.
This continues until about 400 ISO. Then, at 800 ISO, I think the M sized image starts to assert itself. The bin / blend algorithm is starting to improve details because there is more grain in the L4:3 image. From 800 to 3200 ISO there is increasing advantage to the M4:3 image. Edge integrity in the feather starts to suffer slightly as well.
Anyway … L4:3 looks pretty good at 400 and below, but above that I would shoot M4:3 exclusively. DR400 seems to work well.