Advice needed for eager newbie

[NHphotos]

Newbie here and i have a few questions for the professionals:

Simply explain ISO: when to use low & when to use high

Is the i2e software a good purchase? What is its basic functions?

Why do some studio shots have a yellowish tint when using a white backdrop? How do you correct this in studio & what photoshop tools will fix it?

Looking for photography classes; any classes in SC or online tutorials? I'm self taught. Started about 2 years ago for family and now I have a building, on-the-side, photography business. I know enough about photography to make good pics but if I plan to persue this dream I know i need to learn much more!! Still have a full time job & I'm also a mother of two so going away to "school" is not an option. Any suggestions? Feel free to check out my site. Constructive critism and thoughts are welcomed! www.nikkiharrisphotography.smugmug.com (http://www.nikkiharrisphotography.smugmug.com)

Thanks in advance

[leaforte]

Welcome to Dgrin. You came to the right place to hone those skills. Pro's, and creative minds galore!

[claudermilk]

Welcome. I can answer the first and third.

ISO is simply the sensitivity of your recording media. For film, it's set by the chemistry used & is where the ratings terminology comes from. For digital, it's basically setting the gain of the sensor. Think of adjusting the volume on your radio, turing it up gives you more signal (we can discuss noise later).

The yellow tint is one of two things: 1) deliberate coloration by the photographer. And 2) an incorrect color balance setting for the lights. In film, and incorrectly-balanced film, or incorrect color correction filter/gel was used. In digital, the White Balance was left to the wrong setting. For digital it is very easy to fix: get a neutral target (a grey card) and shoot a calibration shot. This can now either be used in post-production to adjust all the rest of the images, or in many cameras, you can use it to set a custom balance value so the images now are properly balanced from the start. I prefer the latter method, it's quicker, easier, and more accurate.

[Icebear]

Your question re: when to use low or high ISO is SOOOO involved.

Exposure involves four basic factors.
1. Amount of light illuminating the scene
2. Shutter speed (how long you let the light strike the recording medium)
3. Aperture (how much of the available light you let through)
4. ISO (sensitivity of the recording medium)

All four of these factors are manipulable by you, the photographer. The easy answer is that (keeping #1 constant) by changing your ISO, you can use different combinations of #2 & #3 to get your desired effect in your photograph.

[NHphotos]

Thanks all! any class/ training suggestions? I'm working with a Nikon D70, but haven't (obvisiously:D ) figured out all the details. Any quick tips that would save me hours of photoshop editing: setting color balance, etc. is i2e a good editing software? Thanks again and I apologize for all the questions!

[gman33]

Good resource

http://www.fredparker.com/ultexp1.htm