high ISO? shutter speed? why & when?

[titan307]

Wondering why, when, should you change these? Should you change it or can you manipulate the photo afterwards to make same changes? What are cause and effect of changes?

ISO-

SHUTTER-

APERTURE-

FLASH/NO FLASH-

Auto/TV/AV/M etc-

[New Hobby]

Wondering why, when, should you change these? Should you change it or can you manipulate the photo afterwards to make same changes? What are cause and effect of changes?

ISO-

SHUTTER-

APERTURE-

FLASH/NO FLASH-

Auto/TV/AV/M etc-

Very good questions. There is a book "Understanding Exposure" that does a great job explaining all of this.

With that said ISO, shutter, and Aperture are all related.
They are to get the sensor exposed to the light properly.

Shutter is how fast the sensor collects light.

Aperture is how much light in let in at one moment.

ISO is how sensitive the sensor will be.


Shutter speed in upped to stop action.

Aperture is used to increase or decrease the depth of field (how much of the picture will have an acceptable focus)

ISO is upped when the other two can not be changed and one does not have enough light. The higher the ISO the more "grainy" the image will be. One does not get something for nothing.

Hope this helps.

[Hermeto]

http://web.canon.jp/imaging/enjoydslr/
http://www.usa.canon.com/content/rebelxt_tutorial/rebelxtlessons.htm

Welcome to POTN and to the World of Photography!

[ryant35]

And of course all three of the items correspond.

You really need to read that book, there is just too many circumstances to try and explain any more than New Hobby did.

Also switch to manual mode, and play around try different settings, learn to use your exposure meter inside your view finder. That's the only real way to learn.

[canonphotog]

For a given ISO, your shutter speed and Aperture control your image exposure.

The ISO you select depends on available lighting and whether or not you are using on camera flash, shoe mounted flash or multiple off camera flash.

Your shutter speed will depend on the lens you are using with a with a general recommendation that the shutter speed is never set slower than the reciprocal of your focal length. ie., for a 200mm lens, keep shutter speed at 1/200th of a second or faster. (and whether or not you are trying to sync with a flash)

Aperture controls your depth of field and works with your shutter speed at your chosen ISO to yield a proper exposure. (provided you set your exposure correctly)

In AUTO, the camera body database examines the light pattern of the scene and picks a shutter speed and aperture for your chosen ISO that should yield a properly exposed image.

In Tv, You select the shutter speed and the camera will select the aperture for your chosen ISO.

In Av, you select the aperture you desire to shoot at and the camera will select an appropriate shutter speed.

In M, you select everything as you see fit using either the built-in camera body light-meter or a dedicated light-meter. Again, for your chosen ISO.

You change ISO for one reason primarily; To allow you to have shutter and aperture settings you want for your image in different lighting conditions.

Your shutter speed and aperture, coupled with ISO, are what allow creative image capture. That, and your own sense of creativity.

This is just the basics of how it works.

Get out a take some pics using the different methods, Auto, Tv, Av, M and start the process to understanding your camera.

I'm sure someone here will also recommend a book or three.

[canonphotog]

I knew there'd be multiple responses while I typed mine out. LOL

[New Hobby]

I knew there'd be multiple responses while I typed mine out. LOL


Wow. Your response blow mine out of the water. Very nice job.

[Riff Raff]

Wondering why, when, should you change these? Should you change it or can you manipulate the photo afterwards to make same changes? What are cause and effect of changes?

Books could be written about just these questions. Hey, I think books HAVE been written about it! ;)

[shannyD]

i dont like using a flash, and i like nighttime photography a lot. so when im not in the mood for a long exposure. i bump the iso up. and i know im getting a lot of noise when that happens. but if its something like getting a shot of my son sleeping. i have to do it fast.

also 5 year olds dont like to sit still long. and neither does my husband. so i always have to make sure that if they are my subject i have to hurry up.

[neumanns]

As the situation requires...

You wouldn't use a tack hammer to frame a house just as a framing hammer sure makes for some roufgh trim nailing.

.
.
.
I think I'll go spread my witty knowledge somewhere else for a while now as it would not be fair to deprive the rest of the world my talent! (This is all tounge in cheek)

[Reflection]

When I first started experimenting with the manual settings, I often read about it - then went and tried it out. Looked at my photos and compared with the examples in the book and the descriptions of what should be happening. Slowly, you understand exactly what they all do and how to use them to your advantage.

[Mum2J&M]

I believe it takes much more than a basic understanding of what each of these things does to be creative in your photography. You have to know what's most important when, and how they all work together to come up with the exposure and effect you are looking for (faster shutter to freeze action, wider aperture for shallow dof, etc.). I have a basic understanding of what all these things do and how they relate to one another... the trick is knowing how to use these tools to my advantage at the moment I'm getting the shot. Sometimes I get it right, sometimes I don't. I believe this will come with time and more practice. I need to be in the right frame of mind to get my head around it. Taking into consideration your subject, metering mode, focal point, ISO, shutter speed, aperture and composition is a lot to think about. When they all come together just right, it's a great feeling.