good place for learning DSLR

[3mrhythm]

i just bought a canon 10d and have never used a SLR camera b4 in my life...

wheres a good resource that i can learn about things like iso and exp and aperture and such?

Thanks!

[Keith Sheridan]

popphoto.com has some decent forums. DPpreview.com has great info on everything. Or you can pick our brains.

ISO is a measure of a films (or cmos sensor) sensitivity to light. You can probably get really technical with it, but the short version is lower number ISO requires more light or time to expose the image. ISO, Exposure time, and f stop are all inter related. If the proper exposure for a certain shot was;

100 ISO f 4 and 1/30 of a second
Than 200 ISO f4 and 1/15; 50 ISO f4 and 1/60: 100 ISO f4.5 and 1/60 are equal exposures.

For the aperature, as the f stop increases the size of aperature (the opening that allows light to contact the film or sensor) decreases. This means that an f stop of 2.8 will esxpose a shot much quicker than an f stop of 5.6. In fact each f stop doubles or halves the needed exposure time. I can never remember all the actual f stop values but at f 4 you may need x amount of light, but at f 4.5 you need 2x amount of light, and f 5.6 you need 3x light. When speed is most important you may hear the term wide open used, this refers to shooting with the aperature wide open, or at the lowest f stop so the image is exposed as quick as possible. You may be wondering why anyone would not shoot wide open to reduce any blurring. F stop also is responsible for the depth of field of a camera. DOF is roughly the distance in front and behind the focus point that is still in focus. With a wide open aperature of say 1.8, a very small distance in front and behind the subject will still be in focus. This can be a good and bad thing. For landscapes it is usually bad, but there are plenty of times a background is very busy and a photographer will want to knock it out of fucus to not draw any attention away from the subject.

Exposure, I assume this is just refering to exposure time, or shutter speed. This is essentially just the amount of time that the shutter of the camera is open and allowing light to touch the film/sensor. Be aware that the slower the shutter speed the more blurred an image will get if you are handholding. Most people can handhold for 1/30 second with out ill effects, but this is just a guide. Some people just have nerves of steel. I know a photographer who got crisp shots consistently with hand held shots of 1/10 second. Also zoom lenses affect blur. If you figure a zoom lense is essentially magnifying your image, it is also magnifying your movement. So an image taken with a 300mm lense may need at least a shutter speed of 1/90 to have the same clear effect of a 1/30 exp on a 100mm lense.

I am sure plenty of people on this forum can answer more and more questions for you, but the best thing to do is to read the thick manual the 10D is going to come with and shoot shoot shoot.

[3mrhythm]

thanks for taking the time to type that that explains it plainly for me thanks!

[Jim Tansey]

Keith,

That was a nice response, touched on all the important things. I enjoyed reading it.

Jim

[Keith Sheridan]

Well thanks. It is about time I give something back to this forum/group.

I am sure there are a ton of things that can be added. Jim, Gumhead, or Stang8s can probably help out.

[stang8s]

I think that was a great summary. The only thing I would add is the correlation between fstop and exposure time. As you mentioned changing 1 fstop doubles the amount of light to the film. Changing one speed does the same thing since they are all doubles 15,30,60,120. So if your meter says you should shoot at 60 and f5.6, you could also shoot at 30 and f8 or 120 and f4 depending on what effect you want.

I notice that digital camera seem to have invented their own speeds and fstops now and that they dont follow this convention which makes it really confusing..

[mikrok]

chris, what lense(s) did you get?

[3mrhythm]

i got a EF28-135mm f/3.5-5.6 with Image Stabilizer (Ultrasonic) ..

got it for 315 shipped ...

[3mrhythm]

will have both my camera and lens on friday! cant wait!!!!

[mikrok]

sweet...same setup here man