Part 1 - Introduction
Part 2 - High ISO Noise
Part 3 - Dynamic Range

Many readers of this site are aware that, beginning with the F10 and culminating with the F30, Fuji has offered arguably the best high ISO performance yet seen in a compact camera. Professional reviewers and photographers alike attributed this ability to a combination of Fuji's proprietary sensor technology, the decision to stick with only 6MP, and expert application of relatively heavy noise reduction. Whatever the contributing reasons, the results were compelling. Here is an example of a resized ISO 1600 shot I took of my son in relatively low light (f/5, 1/38s):



With the F50fd and now the F100fd, a number of reviewers, photography blogs, and Fuji fans have complained about Fuji's decision to follow suit in the megapixel hike. Surely they cannot deliver F30-class high ISO performance with the F100fd, which crams 12 million sensels into a small (1/1.6") sensor, right? Yet Fuji claims that with the F100fd, "ultrahigh sensitivity combined with the next-generation of noise reduction captures the moment in beautiful photos like no other compact digital camera." The truth, known to many readers of this site (though not all or I wouldn't be writing this), is that high megapixel counts don't really impact noise performance the way they are commonly believed to do so.

Everyone knows that noise which is apparent when an image is viewed at high magnification is far less apparent when the image is viewed small. Put another way, downsampling an image improves the apparent level of detail relative to noise. Judicious and skilled application of software noise reduction and sharpening during the downsampling process can further enhance this perception of detail/noise. The opposite is also true. When we upsize images, the apparent detail relative to noise decreases. Comparing a 12MP ISO 1600 image from the F100fd to a 6MP ISO 1600 image from the F30, there is no doubt that the one with smaller pixels (F100fd) will have far more noise when both images are viewed at 100% (pixel level); however, the 100% view is misleading. One should take into account that in producing output of equal size whether onscreen or in print, the high MP image will require more downsampling or less upscaling, either of which will improve the apparent detail/noise in the F100fd image relative to the F30 image. A number of individuals, clued in to this concept, have demonstrated similar high ISO results with high MP compacts relative to the "F30/F31 standard." For example, look here for Prognathous' demonstration of a resized, noise-reduced crop from the 10MP Ricoh GX100 compared to the in-camera JPEG output of the F31.

In theory, for two sensors of equal size and technology (same high ISO read noise and light capturing ability), the pixel (more accurately sensel) pitch should not impact high ISO detail relative to noise performance whatsoever at a given output size. For technical discussion, refer to the many posts by John Sheehy as well as those of Emil Martinec on these matters. While the theory makes intuitive sense to me, I have to admit that in practice it doesn't quite work out. Consider the following small pixel pitch vs large pixel pitch comparisons: 1Ds Mk II vs 5D, G7 vs F30, 1Ds Mk III vs D3. In each case the generation of sensor technology is assumed to be reasonably close, and the sensors are of similar size; hence light gathering ability should be nearly matched. As expected, the small-pixelled cameras show far more "per pixel" noise at high ISOs than do the large-pixelled cameras. Resizing both images to the same size output, these differences are greatly mitigated. Yet from the examples I have seen, the large-pixelled cameras continue to hold a slight high ISO edge even after resizing. Some maintain that such differences come down to software processing (NR, sharpening, etc). I'll leave it to folks like John and Emil to clarify those particulars. The main point here is that the pixel-level view is highly misleading and that the commonly held belief that more megapixels means poor high ISO performance is, at least for the most part, unfounded.

Fuji has undoubtedly been working to improve their sensor technology, but even so it is highly unlikely that the 12MP files from the F100fd will be able to match the 6MP images from the old F30 when compared at 100%. Knowing well that the pixel-level view makes quite an impression and that most people want to have their downsampling and noise reduction done for them, they have enabled the F100fd to offer the ability to process in-camera JPEGs as 6MP files (similar to the F30). Unfortunately I do not have the F100fd in hand for testing. However, a Chinese blog at http://f100fd.seesaa.net/ (English translation by Google here) has quite a few 6MP high ISO F100fd images. Click here to see some of their high ISO F100fd samples. To my eye, they look similar to the output of my old F30 and a bit better than I can get from downsampling high ISO images from other high MP compacts. I don't know if the Fuji advantage comes from better sensor technology or more sophisticated on-board noise reduction software, but the results are impressive. Then again, if you're the type who likes to selectively and sparingly use NR, no luck. The F100fd does not offer RAW and won't let you disable NR on in-camera JPEGs.

Addendum: Prognathous has done some excellent side-by-side testing of the high ISO performance of the Fuji F31 and F100fd. You can find his comparison here. It seems that the F31 is still class leading in this area, though the F100fd has a respectable result.

In the final bit of this three-part look ahead at the F100fd, I'll discuss Fuji's claims for wide dynamic range. That disclaimer once again: I have no inside information from Fuji, nor have I had the priviledge to yet test the F100fd. What follows is simply a discussion of the known technology with a measured dose of good-natured speculation.