For fill flash, there is one thing you you may want to consider. Your typical flash is around 5500 Kelvin...meant to mimick broad daylight. When shooting early morning or late evening, i.e. the golden hours, you may find it beneficial to use a gel to balance the color temperature of your flash with your background. When your background is noticably warmer in color temp than your subject, it is easy to tell that two different light sources were in use and can ruin the harmony of a photo.
Thanks for the info! I set my wb to flash whenever I use it. Will that make a difference too, or should i use gels also? Also when using flash, how strong does the output need to be? I'm thinking 1/64 or 1/32? I don't remember what I had the flash set to, i think it was auto.
For your first question, it depends. For your second question, it depends.For the white balance, ideally, you set your color temp to match your background and then gel your flash to match it. This results in the best balance and if done well, you can't tell that flash was used.As for the power, it completely depends and is not nearly as cut and dry. It depends on how powerful your flash is to start with, how close it is to your subject, what kind of modifiers you are using, etc, etc, etc. I like to use TTL when I can. Makes it easy. For fill flash, I will set a -2 exposure comp to start with and adjust from there. For exact power settings, you need to use a light meter or trial and error as the angle of the flash, the distance to the subject, the ambient light, etc will all come into play. Generally, you will set up your shutter speed, ISO, and aperture to slightly underexpose your subject and expose the background how you want it to be. From there, you will add your flash. You can use a meter, a calibration target, or just adjust based on the histogram.Nothing wrong with using automatic, as long as you know how it's working and you are controlling it instead of it controlling you.