Same lens 400d VS 40d

jamesino · Jan 19, 2008

Assuming I mount the same lens, say the Sigma 17-70mm f/2.8-4.5, on the Canon EOS 400D and 40D, will I notice a big difference, if any, in the image quality?

Is the image quality mainly dependent on the camera body or the lens?

Mav · Jan 19, 2008

I'm pretty sure they both use the same exact sensor, so I think you'd be hard pressed to see any difference. Image quality depends mostly on the person standing behind the camera.

But yeah, the lens will make the bigger difference.

Peanuts · Jan 19, 2008

I believe the 400D has a 'crop' of 1.8X and the 40D is 1.6X so it might seem a little more wide. The quality won't change due to the lens though - you might notice a little less noise however at higher ISOs

keith204 · Jan 19, 2008

Mav said:
I'm pretty sure they both use the same exact sensor, so I think you'd be hard pressed to see any difference.

The white papers for the 40D say the sensors are actually different. The 40D's sensor is based on the 400D's, but the 40D's sensor had more improvements. Mainly, these improvements were to handle higher ISOs much better than the XTi.

The 40D white papers say: "Although the EOS 40D’s single-piece CMOS sensor is based on the Canon EOS Digital
Rebel XTi’s (400D ) sensor design and manufacturing technology, new processes were incorporated
in the CMOS semiconductor fabrication and microlens-forming process. By improving
light-collecting efficiency, the same ISO range and low noise (S/N ratio) as that of theEOS 30D were attained even though the pixels on the 30D are larger."

Peanuts said:
I believe the 400D has a 'crop' of 1.8X and the 40D is 1.6X so it might seem a little more wide. The quality won't change due to the lens though - you might notice a little less noise however at higher ISOs

The 400D and 40D both have a 1.6x crop factor.

I have to say, in owning the 40D, the biggest advantage (personally, for me) isn't the image quality, but the overall feel/appeal of the camera. I upgraded from the XT. Yes, the IQ is better on the 40D, but that wasn't the selling point for me.

Peanuts · Jan 19, 2008

Okay that must have changed. I believe the 350D and 20D had slightly different crop factors. THere you go, learn something new every day!

keith204 · Jan 19, 2008

Peanuts said:
Okay that must have changed. I believe the 350D and 20D had slightly different crop factors. THere you go, learn something new every day!

did they? I'm still thinking 1.6x...

250Gimp · Jan 19, 2008

I have the 350D and it is a 1.6x crop factor. I believe the 20D is as well.

Peanuts · Jan 19, 2008

I've lost my marbles then :lol:

keith204 · Jan 19, 2008

Peanuts said:
THere you go, learn something new every day!

Peanuts said:
I've lost my marbles then

Sometimes you learn something new TWICE a day! :thumbup: Maybe you were thinking about the Nikon vs Canon crop sensor crop factors. Isn't the Nikon D40/D40x/etc a 1.5x? It all gets confusing.