Hi - and thank you in advance to taking the time to read my post! I am looking to get a flash for my Nikon D70s. I am a beginner who does mostly outdoor photography but is looking to do more indoor (big rooms/small halls) photography (and from what I have read you can use the flash to lighten shaded areas outdoors as well). Are teh other brands (sigma, tamron) good compromises in term of quality and price or should I go with Nikon products? How do I balance going for the 800 (making it a more long term investment) with not wanting to go overkill? Thank you?