Begginer Questions! Please Help!

[Country Flower]

OK I did it. Im a new owner of a Cannon XSI. Im reading the manual and Understanding Exposure. The camera came with the 18-55 basic lens and 55-250 lens. Something I want is a lens with capability for more wide aperture like 1.8 and a tripod not for a constant use , only occasional.
Now Im very confuse with the manual controls and others in general
There is any combination of the three parameters (Aperture, Speed and ISO) that is a starting point for an exposure? They have to be in some order with each other? I feel dumb making this questions but...I have to explain that English is not my primary language so excuse if I misspell.

 

[GrillMouster]

Keep reading Understanding Exposure and practicing what Bryan Peterson explains over and over, and eventually you'll understand. There is no "magic" combination of aperture, shutter speed, and ISO that will work in all situations. The settings you use will depend on the lighting and what effect you want to achieve (narrow or wide depth of field, fast or slow shutter speed, etc.). There some combinations that you can use as a starting point. I think the book Understanding Exposure mentions the "Sunny 16" rule. You can use that as a base for exposure in other lighting situations. For example, you may find that indoor lighting may be 8 to 10 stops down from the Sunny 16 settings, and you can get to those settings by an equivalent combination of aperture, shutter speed, and ISO.

Since you're so new to DSLR photography, I recommend that you don't spend too much money on equipment until you understand the basics of photography, but if you really want a "fast" lens, get the 50mm 1.8. It's cheap (can be had for under $100) and a good way to get started with wide apertures.

 

[Country Flower]

Thanks for your advise !!

 

[boBQuincy]

There is a good, fast, and easy way to find a starting point for exposure. Set the camera to Auto (or Program) and take a photo (actually we don't even need to take a photo), check the settings the camera chose for the scene and that is your starting point.

We can use Manual settings to deviate from the starting point but there is an easier way! Rotate the wheel on top of the camera and the shutter speed *and* aperture will move together while maintaining the same basic exposure. Use the exposure compensation button to change the basic exposure.

With these controls we can get just about any valid setting for a scene!