Viewfinder (8.5)
We can't tell the Fujifilm FinePix S5 Pro viewfinder from the Nikon D200 viewfinder. Both magnify the view by about 0.94x (that means they shrink it slightly) and show about 95 percent of the final image. It would be better if the viewfinder showed the entire frame, like the Nikon D2X and D2Hs. What's more, it's useful to have a camera that gets it exactly right. Our shots showed a well-centered view – the S5's viewfinder shows the middle 95 percent of the image on the model we tested.
The S5's viewfinder magnification of 0.94x is excellent. That's closer to life size than many competing cameras, which makes it easier to see detail. Eye relief is very good. Our glasses wearers had no trouble seeing the corners of the frame or the data display underneath it.
The normal 11 autofocus points or 7 wide points show up on the screen, along with an optional composition grid and low-battery and empty memory-card slot warnings..
Shooting data appears below the frame – exposure, mode, white balance, compensations, flash mode, flash ready, frame counters, battery status, meter pattern, ISO, and auto ISO.. As long as the list is, it's really only exhaustive for the Nikon D200. It doesn't show 
dynamic range expansion--the S5's key feature--or Fujifilm's pet “film emulation” mode.
The D200 has a great interface, and Fujifilm was wise not to muck with it. Unfortunately, the apparent use of stock Nikon displays means that the S5 doesn't display vital data that users should be able to easily check in the viewfinder or on the monochrome LCD.
LCD Screen (8.25)
The Fujifilm FinePix S5 Pro's 2.5-inch, 235,000-pixel LCD has a narrow angle of view, and unremarkable color. It appears to be identical to the D200's. That's disappointing because the FinePix S2 and S3 displays were a step up from their Nikon competition.
Flash (9.25)
It’s great news that the S5 uses the D200’s flash system. The Fujifilm FinePix S5 Pro offers the same pop-up flash as the D200, which is fine for a little fill-flash, but its real attraction is that it also acts as a commander unit for current Nikon wireless flashes. We tested the S5 with a Nikon SB800, and the two communicated like old friends. The S5 has all the same options as the D200, running groups of flashes in a variety of exposure modes, and offering four channels.
The S5 syncs up to 1/250 of a second, and it allows exposure compensation from 1 stop above to 3 stops below the meter reading, because really, no one wants to overexpose flash. It allows rear-curtain sync, redeye reduction and long-exposure sync. The pop-up flash's power can be set manually, and it can pop off (weak) multiple flashes.
Lens Mount (9.0)
Fujifilm is hitching a ride on Nikon's coattails, as far as lenses go. It doesn't bundle the Fujifilm FinePix S5 Pro with any particular optic, but it takes current Nikon glass and retains the D200's ability to shoot with old Nikon lenses – even manual focus lenses without electronic links to the camera – the user can set the focal length and maximum aperture for old manual-focus, non-electronic lenses. We put an old 135mm f/2.0 on the S5, dialed in the data, and shot in manual and aperture priority modes without trouble.
