24-70mm L or 24-105mm L?

So I need some advice guys I have never owned a Canon L lens, and with out tax return money they husband says I can finally get one.
I really need a good all purpose lens. BUt I cant decide between the 28-70 and the 28-105.
I mostly shoot portraits but I like to have a zoom I can take anywhere and shoot landscapes and stuff.
So here is my dilema
the 28-70 I hear is very heavy but it goes to 2.8 which I love and its a little more expensive
The 28-105 has a farther range and is a little cheaper but its only a F4
if this lens was a 2.8 I would get it for sure.

I have a 40d with grip
580 ex flash II
430 ex flash
Tokina 11-16 2.8
Sigma 70-300
canon 50mm 1.8

any suggestions on what to do would help!!!

okay, you need to clarify. The 24-70 f2.8 is around $1400. The 24-105 f4 IS is around $1250. The EF-S 17-55 f2.8 IS is around $1150. The last one is the one you want for the 40D. The other ones will be too long for many of the shots you want on a 1.6 cropped camera.

sorry, but there are heaps (and I mean HEAPS!) of posts about exactly this question...a quick search may help you much more than posting a question that's been done over many times.

well sorry I dont get on the boards very much... didnt know that. Sorry if its off limits to ask a question

Well I have shot with my friends 24-70 on my camera and it is fine. I am not sure what you need me to clarify. Ok well if people are just goin to be rude and treat me like a a dumb A then forget this place I will ask people who are not so rude

I'm shooting with a 40D and just got the 24-70 2.8L. I love it. It is now my general lens when I'm not shooting sports. (BTW: I do shoot basketball with it and the 70-200 2.8 )

Like what SuzyView said, EF-S 17-55mm f/2.8 for your 40D. It's 2.8, has IS and perfect zoom range for crop body. Also look at EF-S 15-85 for more range. They are not L, but they are good.

ps. and you need to relax, your attitude wont help getting answer

I want an L series lens

I just bought a 24-70 and I can tell you that it would be a fairly heavy combo with the 40D (which I have) and a speedlight on it. You might want to compare lens weights. At 24mm on the 40D, it is not that wide. Your Tokina would be a better choice for landscapes.

I haven't used a 17-55 but it does sound just about right for your situation. I had a Tamron 17-50 f/2.8 and it worked really well for me on the 40D.

I dont really need it to go that wide. I am very aware that I have a crop sensor. VERY aware.
I was just asking which lens you all liked better...
I want an L series lens because I have borrowed them and I love them.
So if you all are saying that those lense arent for lanscapes, portraiture, etc... then what are they used for?
I need an all purpose lens

Everybody tends to say get the 17-55 for a crop camera. In many ways, they may be right. It all depends on your specific shooting style. I had a 24-70 for years on a crop camera and it was really great. I missed the wide angle and eventually bought a 17-40 to go along with it. This worked out fine for me and I wound up using the 17-40 as a general purpose lens, mainly because it was lighter, BUT I missed the added reach of the 24-70.
I think the 24-105 would be okay on a crop body as well.

It really depends on what you shoot. Often find yourself backing up to get everyone in the shot? Wider is better and you'll probably like the 17-55. Often find yourself needing to "close the gap" and get closer--something I tend to do--to get headshots, etc? Then the 24-70 or the 24-105 will be better.

Between the two is a matter of personal choice too. I like the added reach of the 24-105 and I much appreciate the lighter weight and the MUCH smaller hood. I miss the 2.8 and I don't really notice the benefit of the IS all that much at this focal length.

My opinion is the 24-70 L . You may not always have a 40D, but once you have an 'L', you will always have an 'L'.

17-55 might be a bit too short for portrait even on a crop. I had 24-70L and changed to 24-105 due to 24-70L's weight issue. Difficult for me to wear it all day while on a vacation.

24-70L will definitely have better IQ but I am lazy and I know it. It's better to have slightly compromised IQ than not having fun while out shooting.

Thanks Joe W for all the great perspective... thats exactly what I was looking for.
Also I agree lauderdalems I dont plan on always having a 40D .. The next big purchase will be a 5D MarkII. I need lenses that will grow with me. We all know how expensive this is and I am just trying to build an arsenal slowly
I really think I might go with the 24-70... I just cant resist the 2.8

Well I also have a 40D and just went with the 24-105L (in the mail coming my way). I thought very hard about the 17-55 2.8 IS but didn't like the build quality and lack of range. I already have the Tokina 12-24 and so I thought the 24-105L can pickup where the Tokina stops. You already have a 11-16 so you have the wide end covered just a small gap from 16-24 mm. If you want a L series lens then go with the 24-70L or 24-105L.