GOING ULTRAWIDE WITH NIKON THE D100? IT'LL COST YOU: 20mm f/2.8 Nikkor (left) weighs in at 9.5 ounces, sells for roughly one-third the price of the 23.6-ounce 14mm f/2.8 Nikkor that you would need on the D100 to get wide-angle coverage equal to a 21mm on a 35mm Nikon.
If this maximum size disappoints you, think how few photographers really make larger-sized prints (such as the 11x17-inch photos gracing my office walls). For the vast majority of D100 owners, the camera produces great 5x7s or 8x10s. At the opposite extreme there are digital camera owners who merely want pictures suitable for e-mailing. For that purpose, the same 96MB card can deliver more than 300 images. How? By first changing the resolution, then modifying the JPEG (Joint Photographic Experts Group) compression level. But JPEG compression takes its toll on image quality after a certain point. At the finest JPEG settings, most photographers won't see much difference between an uncompressed file and a JPEG image. But when compression increases beyond 1:10, artifacts-such as moiré patterns, wrong coloration, and jagged edges-can appear.
How much compression can you stand? It depends on how well you recognize JPEG effects. What might be rejected by one viewer may well be very acceptable to the next, just as a 10x15-inch print from a RAW format D100 file might be rejected by a persnickety viewer but would be quite acceptable to most photographers. Subject matter also plays a role.
The D100 offers three levels of JPEG compression-from least to most: fine, normal, and basic. At each JPEG level, you have your choice of three different levels of resolution (see chart on previous page). The less resolution you need, the more pictures you can record on the memory card. When I have time, I promise myself I will try all three D100 JPEG levels, each of which has three levels of resolution, plus a JPEG with no compression, and make prints of all to see the differences. We've suggested that procedure to new owners of the D100 or other digital cameras.
Alas, each different digital SLR seems to have its own set of quality levels so the D100 chart we've shown will not be applicable to other digital SLRs. The D100 has its own Nikon Electronic Imaging Format system as well as the ones I've mentioned.
Fortunately, as you change quality levels, the D100 camera's frame counter on the back LCD and in the viewfinder indicates the approximate number of pictures left on the card. How many pictures remain also depends on the subject matter you shoot. Simple subjects don't require as many MBs as complex, detailed ones, so you may get more shots than the "pictures remaining" counter indicated.
For beginners, the D100 has a default setting that you select by pressing two buttons with green dots simultaneously. This sets normal JPEG compression (see chart), large image-size resolution, speed equivalent to ISO 200, automatic white balance and central-area lockable autofocus. The instruction book says the default setting is "ideal for snapshots."
When you become more conversant with the camera, you can change any image size and quality settings to ones that suit you better. The instructions specify "snapshots" for the default setting, but they don't explain what size snapshots. I guessed it was equal to a 4x6-inch print and thought the default setting could probably produce a 5x7 print at most.