Is the 550D a beast compared to the 400D?

The problem with the rebel series is that the camera bodies don't exactly upgrade - they just get less limitations placed upon them as the upper levels of the camera market upgrade. This means that even if it had the same sensor as a 1DMIV the rebel camera body would still have the coded limitations of a rebel - so saying it has the same sensor is not fully the whole picture.
I would expect (though not had a chance to try) that the usable ISO of the 550D would not be far and above that of the 400D and from what the OP says they really want more usable ISOs. I would expect the 550D to give me a possibly cleaner ISO 800 and 400 - but I would be very surprised if you could easily work at ISO 800 with the camera.
If you want that kind of upgrade you have to move up to the next camera body level in the canon series. A 50D or a 40D would give a user about the same level of usable ISO performance (with 50D images being larger) whilst the 7D gives an ISO performance as well as overall AF and body upgrade over the 50D.


However I also stressed the point about lenses - a good camera body is only going to perform as well as the glass it "sees" through so considering the glass that the OP has is an impotant stage. It might be that putting the money toward a more pro end bit of glass would give a far more improved output from the camera body than simply using existing glass on a better body would.

the 550d will have the same ISO performance as a 7d, just like the 500d has the same iso performance as the 50d. ISO performance is strictly a function of the sensor and thus cameras with identical (550d, 7d) or very similar (500d, 50d) sensors behave the same way.

The cameras have other differences that make the more professional versions attractive. Faster burst speeds, bigger buffers, better body build, af micro calibration, better AF (more points, cross-type points, etc), weather sealing (in some cases), professional control design, CF slots, top LCDs, better viewfinders, and now wireless flash controllers as well.

ISO performance is so similar as to be hard to differentiate.

Overread wrote in post #10118404
The problem with the rebel series is that the camera bodies don't exactly upgrade - they just get less limitations placed upon them as the upper levels of the camera market upgrade. This means that even if it had the same sensor as a 1DMIV the rebel camera body would still have the coded limitations of a rebel - so saying it has the same sensor is not fully the whole picture.
I would expect (though not had a chance to try) that the usable ISO of the 550D would not be far and above that of the 400D and from what the OP says they really want more usable ISOs. I would expect the 550D to give me a possibly cleaner ISO 800 and 400 - but I would be very surprised if you could easily work at ISO 800 with the camera.
If you want that kind of upgrade you have to move up to the next camera body level in the canon series. A 50D or a 40D would give a user about the same level of usable ISO performance (with 50D images being larger) whilst the 7D gives an ISO performance as well as overall AF and body upgrade over the 50D.


However I also stressed the point about lenses - a good camera body is only going to perform as well as the glass it "sees" through so considering the glass that the OP has is an impotant stage. It might be that putting the money toward a more pro end bit of glass would give a far more improved output from the camera body than simply using existing glass on a better body would.

The 550D and 7D do not share the same sensor... The 550D's sensor has some design elements of the 7D incorporated, but it is a different sensor and different processor, at least according to several other posts and review sites.

Overread wrote in post #10118404
The problem with the rebel series is that the camera bodies don't exactly upgrade - they just get less limitations placed upon them as the upper levels of the camera market upgrade. This means that even if it had the same sensor as a 1DMIV the rebel camera body would still have the coded limitations of a rebel - so saying it has the same sensor is not fully the whole picture.
I would expect (though not had a chance to try) that the usable ISO of the 550D would not be far and above that of the 400D and from what the OP says they really want more usable ISOs. I would expect the 550D to give me a possibly cleaner ISO 800 and 400 - but I would be very surprised if you could easily work at ISO 800 with the camera.
If you want that kind of upgrade you have to move up to the next camera body level in the canon series. A 50D or a 40D would give a user about the same level of usable ISO performance (with 50D images being larger) whilst the 7D gives an ISO performance as well as overall AF and body upgrade over the 50D.


However I also stressed the point about lenses - a good camera body is only going to perform as well as the glass it "sees" through so considering the glass that the OP has is an impotant stage. It might be that putting the money toward a more pro end bit of glass would give a far more improved output from the camera body than simply using existing glass on a better body would.

Your point about the 550/T2i vs previous Rebels isn't exactly true. High ISO performance of the T2i is equal to the 7D so it is significantly better than previous Rebels and certainly usable above 800 ISO. ISO 3200 becomes easily usable and 6400 will do in a pinch. You need to go full frame to raise the bar of IQ above a T2i. There are many professional reviews that substantiate this.

Compared to the xD and xxD series you give up the rear wheel, fat body, top LCD, FPS, more advanced high precision focusing etc. with the Rebel that seems to be critical to some but you don't give up image quality or usability for the average amateur.

Good glass is always important for best IQ.

Jim

Hmm interesting I had never heard before about the 550D being that similar in its ISO performance to the 7D!

I wish I had temporary access to a T2i, I would run it through some of my excruciating high ISO tests.

If anyone is in my area with a T2i, let's hook up for some tests!

Taken last night with the new Sigma 50-500 OS at ISO 12800 w/7D, we have hired a new sound guy! Good enough for the parents to love the pic, but probably not up the very high standards others have.

TeamSpeed wrote in post #10118473
The 550D and 7D do not share the same sensor... The 550D's sensor has some design elements of the 7D incorporated, but it is a different sensor and different processor, at least according to several other posts and review sites.

if its the same as the difference between the 500d and 50d, then its quite minimal in terms of real world difference. even on 100% crops its hard to judge whether the 500d or 50d has better ISO performance, and eventually it comes down to opinion. Personally from until ISO 3200 I think they are too similar to choose one over the other, and above 3200 ISO I prefer the 500d.

MLphoto wrote in post #10110720
I'm getting sick of my xti, I've had this camera since 2007... view finder is bad, iso performance is bad, it's just not a good camera, anyone that is... use to be.

I was thinking about the 7D, but the T2i seems to be more attractive since it's almost identical.

So my question is how much better is the T2i quality and the camera overall compared to the Xti?

If you buy a 50d you obtain a better body (and even a better viewfinder) and the cost is the same at buy the new entry level (that remain an entry level despite is a model more recent).

But remember even with an entry level is possible doing good shoot, the importants things are you ability and good lens.

So if you want a more precise answer i think would be better said which lens do you use.

For example do you known that the 50 mm f/1.8 is a pice of gold for performance/prices ratio?
Cheap lens, big result.
Don't following the marketing.

spiralspirit wrote in post #10118964
if its the same as the difference between the 500d and 50d, then its quite minimal in terms of real world difference. even on 100% crops its hard to judge whether the 500d or 50d has better ISO performance, and eventually it comes down to opinion. Personally from until ISO 3200 I think they are too similar to choose one over the other, and above 3200 ISO I prefer the 500d.

Not arguing that point, just correcting the information about the 7D and 550D having the same sensor.

I have both and yes it is a marked improvement. files are larger and easier to edit, crop etc. without losing any quality. just my opinion.

Just replaced my XTi (400D) with T2i. Haven't had a chance to shoot a lot with T2i yet, but high ISO is night and day . On XTi, 1600 was max, 3200 could be enabled through the hack and was barely useable. On T2i, so far 3200 seems to be very decent, and 12800 is about what I was getting with XTi's 3200. Of course I haven't put it through any real tests yet. Also (or rather 1st) there's real video. Also there's a gorgeous screen, and Live View where you can zoom into the picture on screen - without actually zooming the lens - for an accurate manual focus, so using old MF lenses is now easy. Also there's AutoISO, Spot Metering, the ability to use IR focus-assist beam on the external flash without actually firing the flash, the ability to control ETTL flash from camera, better menus, and some other features that I either don't yet know of or forgot. And focus.pocus had already mentioned the better ability to crop. So yes, at least for me, a big improvement.

to the OP i have both right in front of me...want me to take a couple pics from my tripod? maybe a basic shot from iso 100 in decent lighting and then a 1600 iso shot in dimmer lighting?...IQ wise the t2i definitely outshines the xti as do the features and handling...i would say its worth the upgrade even if u never use video...let me know and ill shoot something tonight and resize and post tomorrow

One of the OP's complaints about the 400D was the viewfinder, and that won't be improved much (if any) with the 550D. For a significantly better viewfinder, a 40D/50D/7D is the minimum upgrade...

+1 If the viewfinder bugs you then sadly I think it is the same tiny Rebel pentamirror. You need to upgrade to a 50D or something like that to get a bigger pentaprism viewfinder.

alessandro2009 wrote in post #10119072
If you buy a 50d you obtain a better body (and even a better viewfinder) and the cost is the same at buy the new entry level (that remain an entry level despite is a model more recent).

But remember even with an entry level is possible doing good shoot, the importants things are you ability and good lens.

So if you want a more precise answer i think would be better said which lens do you use.

For example do you known that the 50 mm f/1.8 is a pice of gold for performance/prices ratio?
Cheap lens, big result.
Don't following the marketing.

You're right, a fancy camera will take perhaps sharper, more in focus but still crummy pictures if you have no ability. With ability a disposable camera will take great shots for you. That said, nice features are nice to have regardless of your skill level so it cuts both ways.

The glass in the 50mm f/1.8 is good but the all-plastic housing and focus mechanism are junk...