A flash triiger is something you mount on the hot shoe of your camera that triggers a flash that is off camera.
1) SB-5000 AF Speedlight (Side Question: is this compatible with my Canon 7D Mark ii??)
No
2) Phottix Mitros
It is a good flash but there are may inexpensive 3rd party flashes out there
http://flashhavoc.com/?s=phottix+mitros+
3) Speedlite 600EX-RT (if I just want to play safe, but review says that this is very closed system which means I have to prepare financially if I am to invest on more speedlights.)
No. Yongnuo and Shanny make Canon RT compatible flashes and transmitters. A transmitter is the same a trigger, just more complex. Both those 3rd party manufacturers are significantly less expensive.
BACKGROUNDER:
I am more of an outdoor Photographer. I don't have a studio. So I don't see myself using multi speedlights out there. I want to maximize the use of natural light. And I also want to use bi-color LED lights like the Astra Litepanel or Nila Lights. So, no need really for extra speedlights.
QUESTION 2: Can I simply use any of the above-mentioned speedlight models without buying a FLASH TRIGGER? Especially if I am just on a 1-flash set-up only?
Yes. Many 3rd party flashes come with optical transmission. The pop up flash on your 7D2 can trigger an off camera flash if it is compatible. You will be able to do that with any Canon flash. Optical is OK but it is line of site and other lights can throw it off. That is why RT (radio transmission) is taking over. RT goes through walls. You can get a cheap set of Yongnu tranceivers that will give you off camera RT and ETTL. $60 or so.
If yes, then my FINAL Question is: Which of the above-listed Speedlights are best for my Outdoor Photography and Canon Camera Model (7D Mark ii)?
Do you want to spend a lttile more and go with Canon or are you OK with starting off with 3rd party gear? There are good 3rd party flashes out there.
In all honesty with you lack of experience (and this is nothing pesonal) I would not go off camera flash for your event. Just becuase a flash is off camera does not mean to will make a huge difference. Flash is limited to distance so you are only going to get about 12ft of decent light. You would need multiple lighting which can be tricky not to mention the cost for one event.
Being this is a night event I would just shoot with it on camera, put your camera in P mode, 800 ISO, the flash on ETTL and learn to adjsut the FEC on the flash. There is no way to predict flash exposure. After you take a shot check your LCD and adjust the FEC accordingly and shoot again. The histogram is very helpful and I can post info about that if you like. That lalone will keep very busy all night.
There is nothing wrong with P mode. It will take a lot of pressure off you. Wnen the event starts you will have zero time to react if something goes wrong and it always does. People wll be talking to you, etc so no time to think. Do not shoot in AV mode or you may get into trouble. Many like to put the cam on manual (flash on ETTL) but now you need to learn how to balance the ambient light and the flash. It is not that difficult but there is a learnning curve humpo to get over.
I prepared for 6 months for my first wedding. I took lighting courses and read eveyrthing I could including the book kvbarkely listed and I did not feel close to being ready when game day arrived. Here is a great site to learn about how to create pleasing on camera flash exposures. You may or may not have enough time to get through this. You willl probably shoot direct fllash but explore bouncing the flash if you have soemthing to bounce off.
Start in the blue column on the right. Scroll down to - Flash Photography Techniques.
http://neilvn.com/tangents/
