I am a beginner with a 50D body and thus has some stupid questions during my lens selection:


Q1. EF24-70mm has a horiz view angle of 84 degree vs.EF 17-55mm has a horiz view angle of 68 degree:


a)Isn't it shorter focal length gives wider angle of view?


b) if I have a 24-70, then it covers what I can take with 17-55?


c) why 24-105 doesn't provide horz view angle in its spec? At least I can't find it.


Q2. If I want to take pictures of my 2 yr old kid indoor, assuminghe is not that cooperative in keepingstill,is it qualified as "freezing action in low light" and thus I need to consider f/2.8?


Q3. If I use a flash with a non-f/2.8 lens, can I achieve "freezing action in low light"and for the situation I mentioned in Q2 above?


Q4. I saw posts mentioning Tamron 17-50mm f/2.8 with its price much lower than EF 17-55. I assume it is compatible with 50D? Any people used this before can give me more insight comparing with EF 17-55 or even EF 24-70 (w/o considering the extra 20mm focal length)... I am not a professional and thus not really looking for poster size IQ.


Q5. I am considering the following 2 combinations:


a) 50 f1.8 + Tamron 17-50 (low light & wide angle landscape) + EF 24-105L (general use, travel)


b) 50 f1.8 + EF 24-70 (worrying a little bit heavyto carry around formy kid, and travel)


Not considering a zoom lens going to 200mm yet as I don't think it is necessary for now. If I have a 105mm, then, it is already 168mm on my 50D, which should be ok.


Please advice.