Next lens? apc/full frame compatibilty

[Gremlin]

Ok, keeping in mind that my brain has trouble understanding a lot of the technical things associated with DSLR's, 35mm ones were easier,
currently playing with a 450D and wishing soon to go up to a either 40/50D or 5D most likely 2nd hand preferably off here rather then fleabay,
my question, I tend to shoot a lot of friends at events in costumes etc and since playing with the 50mm nifty fifty lens and realising the f1.8/2.8 range is perfect and lets in loads more light, I think a zoom lens would be next on the list, lighting is usually ok maybe a touch of fill flash, but the extra light of a 2.8 should be enough.
Currently looking at the Tamron 17-55mm f2.8 (pretty sure thats its specs) but can this lens be used on the 40d/5d camera bodies as they go from apc (small frame?) to 5d full frame?
Are all lens interchangeable with the different bodies? ie 450d - 40d- 5d?
Or have I been reading information incorrectly? Sorry if this questions been addressed earlier i couldnt find it.

Thanks in advance

Grem

[Dark Mist]

Hi
if you buy the Tamron 17-50 it will be fine on any of the models with an APS sized sensor but not on the 5D. This will be true of the equivalent Canon, Sigma and Tokina lenses too.

Almost all lenses that can give a wide angle view on a camera with an APS sized sensor (Nikon 14-28 is an exception) only have an image circle big enough for that and will vignette like crazy on a full frame sized sensor. On Canon cameras they will foul the mirror too so they can't actually be fitted.

[Gremlin]

ah bugger, I thought there was something like that for it but thought wait for an expert,
so I have the wonderous choice of get a 40D stay in the midrange or dont buy anything else and get the 5D and have to buy all new glass? would that be correct? As the three lens i have for the 450D wont work right?
And with that, anything under 5D would be considered to be less then pro-spec? do any pro's use anything under 5D and get results they want or does the jump to full frame mean replacing everything?

[Cliff]

get the 5D and have to buy all new glass? would that be correct? As the three lens i have for the 450D wont work right?

Grem, it depends what lenses you already have. EF Canon lenses can be used on all Canon cameras. EF-S lenses can't be used on full frame cameras.

[Gremlin]

all i have atm is the standard kit, the nifty fifty and a old 100-300 that i had froma 35mm, Ive held off buying anything mroe until I figure which way to go, 40-50D or 5D as I knew there was some issue with the lens compatibility, which DM pointed out, the kit 18-55 does ok but I know i can get more out of this 450D with better glass, also tossing up if the 40-50D is actually a worthwhile upgrade for event photos, as if i can get the results I want with the Tamron 17-55 f2.8 i dont see the need to spend thousands until I get more experience exposure etc etc, so if i started buying 2-3 more bits of glass i e the tamron and a 70-200 tele as well as a 85mm portrait lens, do I stay within the APC range or do i have no other option of going up to say 5D, but then Id have to buy all new glass again.
Is a 40/50D a good body to use for events? with appropriate glass?

sorry for loads of loaded questions as Im about to start spending money again, I want to ensure Im not going to regret it, I need this gear to last me at least 24mths before i look at upgrading again so thats why i was thinking 40-50D.
Hopefully Im making some sense.....

[Gremlin]

only other differences that come to mind are framerate iso and diff between 40 to 5d is full frame vs apc?

[dulvariprestige]

If it's events you're mainly shooting, I'd probably go lenses over a 40 or 50d, and when funds permit, step up to full frame.
If I was in you shoes, I'd be looking at a canon or sigma 24-70 2.8, or even a 24-105, I was at a fancy dress party tonight, and my 24-105 on a 7d was still wide enough to get big group shots, but was perfect for singles, couples and small groups.
If you need to go wider, then maybe look at the canon 17-40, it is an f4, but you did mention using flash, or if you want faster, canon's 16-35 2.8.
I'm no expert though, as I'm still very new to photography.

[Gremlin]

Thanks Jayde, I am kinda stuck on the 2.8 as I seem to be able to get away without flash, the events I speak of are daylight indoors but usually have a fair amount of natural light as well as artificial thanks to skylights etc, Id noticed with the kit lens 3.5 was on the borderline of handheld and wanted flash. Ill definitely look into the sigma 24-70 and 24-105 Id only been looking at the Tamrons as Id read loads of good reviews ie sharpness and the IS system they use seems to be good as well. I dont know much about the Sigmas but have used Tamrons in the past with good results.
Thanks for your reply its very useful as everyone else, I can only learn by asking :)
Cheers
Grem'

[dulvariprestige]

No worries Grem, the 24-105 is a f4 canon with IS, so probably not quick enough, unless your subjects can stand still for the shot, also I don't think tamron have IS in these focal lengths.
Another thing to mention is that there are 2 versions of the sigma 24-70 2.8, the newer version has HSM and the older version does not, and the older version is around half the price of the HSM version, if you see a HSM model for around $500-600 new, it will be for a nikkon.

[Gremlin]

hmm more i consider it now I still might get a 40/50 as Id want a backup body, and just get more glass for the moment and just use a 450/40 combo for a while until I either break something or "have to" go full frame.
thanks for the replies folks :)
Grem