|
Forum: Photographic Technique
11-26-2008, 10:08 PM
|
| |
Sorry Duplo, the part about the metering was just a general rant not pointed at you. A common theme is “I took a bad photo because the camera metering is bad”. You are obviously not one of those. Knowing the limits of your equipment is always a good thing and limits are not always equipment fault. Knowing things like your camera metering is not as liner in dim orange light can be important to shooting nightclubs but of little use to someone who shoots car races. To some that do catalog shooting a lot they may take the time to determine the T-stop of there lenses so when they change a lens they know how much to change the shutter speed. For them anything that helps get more photos out help. For some they may never notice any of this. To you these thing are important.
Again sorry Duplo if it look like I was pointing something your way.
DAZ
|
|
Forum: Photographic Technique
11-26-2008, 08:29 PM
|
| |
Like a lot of things Duplo just because we can measure something doesn’t mean that it is significant. Cameras and lenses are built to such high standards we sometimes think they are scientific instruments. They are not. They are machines that are built better then they needs to be most of the time. I to can see it on my lenses but just don’t need to worry about it. A long time ago lens revues use to measure this but with TTL metering they dropped it as not important.
Measuring some things are pretty much useless. Take multi point metering and this is not to say don’t use it as it is a useful tool. With multi point it is basically not possible to determine what the camera is metering. Move the camera just a little and the metering point fall on different things. Even if they don’t move the data is put into an algorithm that some engineer come up with to try and make a good exposure. Change engineers and you change exposures. The only thing you can say is that it deferent then some photographer thinks it should be exposured. That is why cameras have exposure compensation controls so the photographer can make it what they want. Most of the time it is just an excuse to bash one camera brand over another.
DAZ
|
|
Forum: Photographic Technique
11-26-2008, 08:01 AM
|
| |
Looks like the deterrents between T-stop and F-stop. Put simply an F-stop is a mathematical relationship between focal length and aperture. Each “full” stop is half or twice as much light but is not telling how much light is transmitted though the lens. How much light is transmitted and not absorbed is a T-stop. A lens with less glass, better glass, less transitions and better coatings (a fast 50) will usually transmitted more light then a lens with more glass, lower quality glass, more transitions and not as high-quality coatings (slow zoom). There is also a mechanical part, as the camera has to move the aperture blades at the time the photo is taken. This means there can be a small change even on the same lens from photo to photo. Most of the time as we use TTL metering it is not important. For some who do exaction studio work and stop motion it can be critical. These people will use mechanical F-stop lenses and possible determine the T-stop of their lenses. See F-number - Wikipedia, the free encyclopedia for some more info.
DAZ
|
