It could be user error, or it could be factory error, depending on whom you talk to. Nikon cameras use a mechanical lever to control the aperture on
their lenses. Even the new "G" lenses have this lever, but not the aperture ring. As you read further, you'll wonder why Nikon is even making the "G" lenses.
Most of my photos with the D100 have been in broad daylight, at high shutter speeds. I remember when I got finally received my D100 from FedEx, I couldn't wait to put on the lens. I purchased an AF-S 80-200mm lens a few months earlier and having this
kind of lens lying around with no camera to use it with, was just driving me crazy. As soon as I could, I went down to the local river and took a lot of shots of boats and jet skiers. The first set of photos I just totally messed up. I accidentally had the D100
in "S" mode at 1/4000sec. Needless to say, my photos were a little dark and underexposed. But should they have been so underexposed?
Second situation became clear there was something wrong. I was at a hockey tournament, and I could only get the desired shutter speed at ISO 6400. Not being too familiar
with the camera, I was thinking it was myself--the user. I've used 35mm cameras before and they never gave me this problem, and even used digital before and never
gave me such a problem. So, I was a little confused. What the hek was going on?
Since I wasn't shooting that much at the time, I have to admit that I could have noticed this problem a lot sooner. I was cleaning my AF-S 80-200 and the 50mm 1.4D. I noticed the a little
lever on the lenses, and when I moved them up and down, the aperture blades on the lenses moved completely open and completely closed. This made me think. I noticed the D100 had a lever, which
looked like it was supposed to "catch" on the aperture lever on the lenses. Not putting all of this together at the moment, I posted a question on DPR whether they thought my D100
was defective, or one or more of my lenses.
Thanks to an attentive reader, I was instructed to take a look at the lever on the camera, and told to
see if it was bent. That's when everything made sense. The two levers were not catching. Sure enough, when I attached my 50mm 1.4D lens, the D100 would not catch on the lens lever, and as a result,
the aperture blades could not be adjusted correctly.
After noticing this, I put a little pressure on the D100 lever and pulled it forward.
Shown above and on the left-side, is the aperture lever for Nikon lenses
Wouldn't you know, the 50mm 1.4D lens actually acted like a 1.4 lens! This made me think about all the other
photos I shot. Were all of my previous photos underexposed to a degree or could they have been shot in a much
better aperture? Yes, a lot of them could have. Especially my hockey shots. I will never know when the lever on the D100 ceased to work on the lenses or when it worked sometimes and not at other times.
Above is another view of the D100 Aperture Lever
WHAT YOU SHOULD BE AWARE OF...
The reason I post this experience, is because this aperture lever issue can seriously affect your shooting. In addition, if you own Speedlights, such as the SB-80DX, your photos could be either seriously
underexposed, or overexposed. In my case, shots I took with the 50mm 1.4D lens were underexposed and I was thinking I had problems with the SB-80DX. Since the 50mm 1.4D lens' aperture was not being moved by the D100's aperture
lever, it was stuck at the minimum aperture (highest number). So, when I took a shot on my D100 and it said f/5.6, it was actually f/16! The flash was thinking I was shooting at f/5.6 and didn't give me as much light/power, as I would have needed
at f/16. What we have is the D100 indicating it was set at f/5.6, but it wasn't. And when you take photos, you won't know you have
a problem, because the EXIF data will record what the camera says is correct--not what is actually going on.
My word of advice, is to MAKE SURE your D100 aperture lever is working properly before you do anything serious like a shooting event, because you will have a problem with misread aperture levels, your flash unit won't work properly, and your expensive lens you paid good money for to get the best possible shot, will be under-performing.