How to know Av and Tv and lens???

[KobraCarry]

Is it all trial and error or is there an easy way to figure out what Av and Tv I should be using when I'm taking shots of different things??? What lens should i use? Should I take the same shot with multiple lenses and settings? Oh, and if you couldn't tell, I'm a newbie!

[Wil_Bloodworth]

Mike,

This is a very lengthy question. I'm going to be as terse as possible and still answer your question.

Aperture Priority (Av) mode lets you set a specific lens opening diameter and then the camera will calculate what the shutter speed needs to be in order to get the appropriate amount of light through the lens in order to correctly expose the image. This mode is useful for controlling depth of field (the amount of sharpness in front of and behind the subject you're focusing on). The smaller the F number, the less depth of field you have.

Shutter Priority (Tv) is where you tell the camera exactly what shutter speed you want to have and you let the camera choose the lens aperature in order to correctly expose the image. This mode is typically used when you need to stop motion at exactly the same rate... such as shooting sports or some other fast motion subjects.

I hope that helps you understand when to use either of those modes.

- Wil

[Duffy Pratt]

It is not simply trial and error.

Shutter speed's main impact is on how much the action will be stopped. If you are looking to stop action, then you need a fast shutter speed. The faster the action, the faster the shutter speed. For sports, I try to keep things up around 1/400th of a second, but people are slow, and you can get away with slower speeds. Faster can be better. For shooting my dogs playing, I try to bump that to 1/640th of a second. Conversely, if I'm trying to blur a shot, I will lower the shutter speed. The big cliche for this kind of shot is a waterfall that shows blurry water to convey the feeling of motion. Shutter speed may be down to 1/30th of a second, but it will depend on the waterfall.

Aperture mostly has an effect on depth of field. A small aperture (large fstop number) will have a greater range of objects that are in focus. A large aperture will narrow the range of objects that appear in focus. To separate a subject and blur the background, you can start by picking a large aperture (small fstop number).

There are two main considerations when picking a focal length. First is angle of view (or magnification). A wide angle gives a wide field of view, and a long lens gives a narrow field of view and high magnification. Second, a wide angle lens tends to help if you are trying to have a large depth of field. And a long lens will have a short depth of field.

Those are the main basics, in a nutshell. Even without much experience, its possible to make intelligent choice about lens selection, aperture and shutter speed. With experience, the ability to make those choices will become easier and easier. If you spend a year with nothing but a 50mm lens on your camera, and you think about what you are doing and spend some time studying the results, by the end of the year the characteristics of that lens should become almost second nature to you.

Hope this helps

Duffy

[KobraCarry]

Originally Posted by Duffy Pratt

It is not simply trial and error.

Shutter speed's main impact is on how much the action will be stopped. If you are looking to stop action, then you need a fast shutter speed. The faster the action, the faster the shutter speed. For sports, I try to keep things up around 1/400th of a second, but people are slow, and you can get away with slower speeds. Faster can be better. For shooting my dogs playing, I try to bump that to 1/640th of a second. Conversely, if I'm trying to blur a shot, I will lower the shutter speed. The big cliche for this kind of shot is a waterfall that shows blurry water to convey the feeling of motion. Shutter speed may be down to 1/30th of a second, but it will depend on the waterfall.

Aperture mostly has an effect on depth of field. A small aperture (large fstop number) will have a greater range of objects that are in focus. A large aperture will narrow the range of objects that appear in focus. To separate a subject and blur the background, you can start by picking a large aperture (small fstop number).

There are two main considerations when picking a focal length. First is angle of view (or magnification). A wide angle gives a wide field of view, and a long lens gives a narrow field of view and high magnification. Second, a wide angle lens tends to help if you are trying to have a large depth of field. And a long lens will have a short depth of field.

Those are the main basics, in a nutshell. Even without much experience, its possible to make intelligent choice about lens selection, aperture and shutter speed. With experience, the ability to make those choices will become easier and easier. If you spend a year with nothing but a 50mm lens on your camera, and you think about what you are doing and spend some time studying the results, by the end of the year the characteristics of that lens should become almost second nature to you.

Hope this helps

Duffy

That's exactly what I was looking for; a good starting point for different things. All the photo books I have and none of them give you a good starting point for different objects!

[carrbowl]

I've always wondered this??? why is Av named Aperture priority and Tv for Shutter-------??? That doesn't make sense to me with those particular names..

[rott]

Originally Posted by carrbowl

I've always wondered this??? why is Av named Aperture priority and Tv for Shutter-------??? That doesn't make sense to me with those particular names..

"Aperture value" and "time value". I didn't know either. You gave me an excuse to go look it up! Thanks!

[L Stegall]

I think Bryan Peterson's book, Understanding Exposure, does a great job of covering this topic. If you are a "newbie" and don't have it, I highly recommend it. It will be a reference book you come back to again and again.

[carrbowl]

WEll thanks Mike...I think my memory will serve me better now that I actually know what they stand for!!!

[KobraCarry]

Originally Posted by L Stegall

I think Bryan Peterson's book, Understanding Exposure, does a great job of covering this topic. If you are a "newbie" and don't have it, I highly recommend it. It will be a reference book you come back to again and again.

Thanks for the info. I just placed an order for a copy on Amazon.com

I'm not really a newbie, since I've been into photography for a long time. But I got so hooked on point and shoot cameras, and it's been many years since I was serious with my 35mm, that I'm trying to re-learn all the basics. I get compliments on a lot of my photos, but I also try to take the same shot with multiple settings to insure something comes out exactly like I want it to. I'm trying to learn to be able to do that without having to take multiple shots! I'm a born-again-newbie! :)

[L Stegall]

Hey, I hear that! I spent endless hours in college in the darkroom, but then spent years with a P&S when I had a small child and very little time. Welcome back - I think you'll like the book.

[dfwlens]

One of the best and most comprehensive books for a newbie.

http://www.amazon.com/gp/product/1584503564