XSi/450D maximum usable ISO?

[mark_pierlot]

<p>I just bought my wife and daughter a used XSi body in great condition for next to nothing. I have numerous EF lenses, and think the Rebel will make a good replacement for our point and shoot, as well as be a good tool for teaching my daughter the fundamentals of photography.</p>

<p>My question is simply, what is the maximum usable ISO of the camera? Our Canon A640 is hopeless above 400, and I'm hoping the Rebel is at least decent at 800 or a little higher.</p>

[Spearhead]

<ol>

<li>Depends on what post-processing software is used.</li>

<li>Depends on sizes for image viewing.</li>

<li>Depends on the viewer's tolerance for noise.</li>

</ol>

[alan_bryant1]

<p>Jeff is right in saying noise is relative; however I would expect the XSi to easily outperform the A640. The XSi at 800 will probably be significantly better than the A640 at 400. You can improve it even more by shooting RAW and postprocessing well.</p>

[jamie_robertson2]

<p>My bet is that the XSi will be as good at 800 as your A640 is at 200.</p>

[PuppyDigs]

<p>Our local CVS still has the XSi on sale for $599 with kit lens, albeit 5 years out from its debut! I'm sure a well exposed carefully processed RAW file with a wee bit of Neat Image or Topaz Denoise will look pretty dad burn good at ISO 800 to 1600. The 12MP CMOS was sort of a sweet spot in the Rebel line.</p>

[mark_pierlot]

<p>Thanks for the observations, guys. Now I don't feel so bad about getting such an outdated camera. ;-) And I paid a mere $150 for it (<em>sans </em>lens).</p>

[dogbert]

<p>Whe I owned it I regarded ISO 800 as usable without too many concerns provided exposure was accurate, but ISO 1600 as an emergency setting - still fine for snapshots, however.<br>

I imagine a well exposed shot at ISO 1600 would still look better than the A640 at ISO 400.</p>

[Andrew Gosden]

<p>I don't usually use 1600 on my XSi, but I forgot it was set to that when I took this picture. This is from a RAW file converted with the Lightroom default settings. I did not do any additional sharpening or noise reduction or anything else. This may not be big enough to really show much, but I figure an actual picture would be more helpful than more words.</p>

<p> </p><div></div>

[mark_pierlot]

<p>Thanks for the image, Andrew. It looks pretty clean. I wasn't expecting mere full stop ISO increments, which is going to take some getting used to.</p>

<p>My six year old daughter was thrilled to get the camera, and had a lot of fun shooting with it yesterday. I wanted to keep the weight down, so I attached my 40/2.8 STM pancake. That combo is not too much bigger than the point and shoot.</p>