I currently own a 40d and 24-70mm f2.8L.  But I need something a little wider... and I need it soon.  I can't make up my mind whether to rent a 17-40mmL ($60) to use with my 40d or just go ahead and get the 5d and use my current lens (24-70).  I'm not doing both.

17mm on a 40d is the equivalent of 27mm on a 5d, so at the wide end (24mm), my current lens would just be a bit wider if I buy a 5d.

I need the wide angle for a very large group photo (indoors).  I know this is a lighting nightmare... so any pointers on lighting would be helpful too.  I have a 430EX with a diffuser and an AlienBee 800 with a softbox, but I didn't originally plan to use the AB800.  I doubt this photo will ever be printed larger than 8x10, so I was thinking just crank the ISO up and bounce the 430ex off the ceiling (with me on a ladder to get slightly above the group).  I was also thinking the 5d may handle noise better, so I could get away with higher ISO.

My other thought is that the 40d only uses the center of the lens, so it might show less distortion.  Does anyone here have a 5d and 24-70mm?  If so, is there much distortion at 24mm?  But now that I think about it, I'll be cropping this to 8x10... so that may not matter anyway.

Just to add a little more info.  I do portraits and occasionally a wedding.  I use the 40D as my primary and have a Rebel XT for backup (second camera at weddings).  So, it wouldn't hurt to have a 5D when the next wedding rolls around... but the XT does okay.

So... someone please push me in the right direction!

Are you talking about buying the 5D or just renting it?

IMO, if you shoot at 17mm you will have more distortion at the edges AND in the center than you will full frame at 24mm.  I am working this over in my head as I type, but I think you will end up standing a little farther back with the full frame camera, which will give you a more natural perspective, and may help you even out the lighting.

I'm talking about buying the 5d.  I was hesitating on buying the 5d because 1, it's a lot of money, and 2, I'm sure a replacement is due soon.

I was about to rent the 17-40mm (to use with my 40d) and it got me thinking that's $60 I could put toward buying the 5d (in addition to the current rebate).  That doesn't put much of a dent in the price, but every little bit helps.

I have a 5D and a 40D.  The 5D usually has the 24-70 f2.8L on it.  I've had the 17-40; it's a great lens value. I replaced it with the 16-35 f2.8  (every stop counts).

Since you already have the 24-70 (I'm presuming that we are talking about the Canon L lens) go for the 5D.  There's currently a $300 instant rebate so the body is now well under $2K.  When a next generation model is released it will be over $3K. Spend the difference on the 17-40 and a 580 EX II

The 5D is also a great wedding camera. and you'll have the benefit of a similar control layout to the 40D unlike the Dreb.

Quoted: I have a 5D and a 40D.  The 5D usually has the 24-70 f2.8L on it.  I've had the 17-40; it's a great leans value. I replaced it withthe 16-35 f2.8  (every stop counts). Since you already have the 24-70 (I'm presuming that we are talking about the Canon L lens) go for the 5D.  There's currently a $300 instant rebate so the body is now well under $2K.  When a next generation model is released it will be over $3K.

That's a good point.  The 5d is barely in my price range as it is now... so if you're right, the replacement will be well over my budget.

And you're correct... the lens I have is the Canon 24-70L.

Quoted: That's a good point.  The 5d is barely in my price range as it is now... so if you're right, the replacement will be well over my budget. And you're correct... the lens I have is the Canon 24-70L.

I paid just over $3K for the 5D when it first came out. No reason to expect it's replacement to come out at a lower price; the 1DM3 and 1DsM3 were both slightly more expensive than the cameras they replaced.

If you are considering buying the 5D, just do it.  FWIW, I think the 5D is STILL one of the best cameras out there for serious work, and it is priced well right now.

Thank y'all for the input... I'm almost convinced to click the "buy" button on the 5d.  I'm going to think it over a little more and try to make up my mind later tonight.

Canon 5D along with the 17-40 and 24-70 will be killer.

Multiply the EF-S lens by 1.6 and you get the equivalent full frame focal length.  Multiply the EF focal length by 1.6 and you get the effective focal length on a 30/40D.

BTW, EF-S lenses can not be used on the 5D, Ds Mark II/III or D Mark II/III.  They can only be used on the XT line, 20/30/40D line.

Well... I decided to buy the 5d.  I went ahead and threw in a 50mm 1.4 so my 40d wouldn't be lonely when I took the 24-70 away from it.  I looked back at some of my favorite photos of my kids and many were taken with the XT and my 50mm 1.8.  So, I think the 40d with the 50mm 1.4 on it most of the time will serve me well.  When I do a wedding, I usually rent a 70-200 2.8 IS... now that can go on the 40d instead of the XT which should be a little easier to hold.

CR