I am wanting to upgrade from my canon 50d. I am looking at the new 6d and 70d. any suggestions?

[kmcmahan]

I shoot a lot of sports and in low lighting or where flash is not premitted. I also am not sure about a full fram lens. Any suggestions?

[ebiggs1]

Although I don't have a 50D, it is a pretty nice camera. I have one friend with one and from what I have seen it is a capable camera. I doubt a 70D is going to yield you much.

But a 6D, although not my favorite camera, would be a better choice, IMHO, of course.   And in your case, is exactly the person Canon has aimed the 6D at. It is their entry level FF.

FF and crop bodies each have their place. Strong points and weak points. There are other features of the newer bodies to consider also. LikeDIGIC5processorsforinstance.

Go try a Canon 6D.

[cicopo]

What lenses do you currently own? 

[kmcmahan]

I have a tamron.

[cicopo]

Is it for crop bodies ONLY? If so you'll need to shop fora replacement if you go full frame.

[kmcmahan]

What is a full frame lens?

[cicopo]

Lenses designed to fit Canon's EF mount are considered full frame because they permit light to cover a sensor that is the same size as the area used in 35 mm camera format. Crop bodies have a smaller sensor and use EF-S lenses BUT they can also use EF mount lenses. Lenses made specifically for use on crop bodies don't work properly on full frame bodies (EF mount). Sigma & Tamron make lenses for both EF & EF-S setups. 

[kmcmahan]

So if I buy the 6D with a lens on it, I should be fine, and see a huge difference im my images compared to the 50D. 

Also will I still need a external flash?

[cicopo]

A difference, MAYBE: A huge difference,UNLIKELY unless the lens you use on the 50D is crap. Where you may see an improvement is at higher ISO's or in very low light AF performance. There will also be an improvement with (I think it comes with ) the 24-105 L IS lens because it's a very good lens. However the same lens should show an improvement on the 50D too

[ebiggs1]

You have a Canon 50D and a Tamrom lens? Which Tamron do you have?