The Fuji S3 CAMERA can NOT utilize a custom tone curve. A Fuji S3 owner can NOT load a custom tone curve into his camera using a computer and software,simply because the Fuji S3 has no provision for a user-installed Custom Tone Curve.
Curvemeister. Problem is, Curvemeister works ONLY under Windows, and it has absolutely nothing to do with any CAMERA and it does not automatically work at the time of shooting. Using Curvemeister means that each file must be processed and must have a curves adjustment applied to the files AFTER they have been shot.
Uploading a Custom Tone Curve allows one to apply a Curves adjustment IN THE CAMERA, at the moment of shooting. There have been numerous free and widely-distributed Custom Tone Curves,particularly for the Nikon D100 and the Nikon D70. With names like "Point & Shoot", "White Wedding", and "Provia", a quick Google search using the string of Nikon + Custom Curves will lead you to several pages of links explaining the situation and which have curves offered for free use.
Bottom line: Nikon allows users to envision,create, and save customized tone curves using Nikon Capture software. Then,using Nikon Capture, the D-SLR is connected to a PC or Macintosh,and the curve is "uploaded" or "transferred" DIRECTLY TO one's D-SLR camera. Then, when the Custom option is selected on the appropriate camera (like a D70 or a D2H or a D2x or a D100,and so on), the camera then CREATES images which come off the storage card already modified by the Custom Tone Curve being selected.
Check out this web page for valuable Nikon D100 and D70 curves:http://fotogenetic.dearingfilm.com/custom_tone_curves.html
I've been using a custom tone curve at times with the D2x. It allows me to get the widest-possible dynamic range with the D2x,artfully pegging my highlights just shy of clipping, along with establishing a decent black point, with good contrast throughout the midtones, all with Point and Shoot ease. And, it allows me to set the EV Comp to a whopping Minus 1.3 to Minus 1.7 stops at the time of shooting, which builds shutter speed, or which allows smaller f/stop values. If there's a fault with the D2x, it is that it allows me to use Nikon Capture to load JUST ONE custom tone curve to the camera at any one time....I wish the D2x had provision for three different custom tone curves. But it,like other Nikons,only allows ONE custom tone curve to be installed in the camera. (NOTE from early 2009: a firmware update Nikon released well after this was written allows four custom curves to be loaded into D2x bodies which have had the new firmware applied.)
It's clear I think that there are a number of people who really do not understand exactly HOW and WHAT a custom tone curve DOES,nor how one would go about loading a custom tone curve INTO their D-SLR.
Custom Tone Curve design,modification,and sharing was part and parcel of the Nikon D100 user group on dPreview for well over two solid years. I have two custom D2x curves which are,to me, exceedingly valuable tools which allow me to shoot high-volume assignments with almost perfect results,right off the card. I have a carefully-tweaked cutom curve loaded into my D2x at this very MOMENT....and the curve is IN THE CAMERA'S MEMORY,and to put the curve into the camera I used a cable and a computer and Nikon Capture 4.3.2 software. Here is a link to a dPreview thread with a custom curve designed for the D2x,as well as ample feedback and instruction on its use.
And for those of you with the Nikon D70,here is a post that shows illustrations graphing out 10 different D50 curve responses,as well as having a lot of good information on custom tone curves.
If you have a Nikon D50,D70,or D70s, check here at this URL for a small piece of freeware that will allow you to design and modify custom tone curves for uploading to your Nikon camera, OR for use in post-production after the fact.http://home.tiscali.dk/mhj/Foto/TupMaker.html ANd for those who want to see just HOW a curve can be uploaded to a Nikon D-SLR body, take the tutorial tour here:http://www.oxfordeye.co.uk/toneup/tutorial/index.html