A question about 40D and exposure

Well, after picking up my 40D two weeks ago I have an observation.

After using a 30D and a 400D for a considerable amount of time, I was fairly used to the shutter speeds I could achieve using different combinations of ISO and aperture control.

Especially with the 400D, I often found myself in situations where I simply could not achieve the shutter speed I needed, even by increasing the ISO into 'no man's land'.

With the 40D I am consistently finding myself surprised at the shutter speeds I am able to achieve using 'reasonable' (ie <800) ISO's.

Now, my question is, was I basically unlucky enough to have a duff 400D and never realised, or is the 40D that much more effective at making use of available light?


If so, it's something no-one else seems to have mentioned...especially in all the conversations about '40D and 400D have the same IQ'....

Any comments appreciated.

Is this using the same lens on each? Shutter speeds should always be exactly the same given the same exact quantity of light, same aperture, and same ISO setting no matter what camera.

Hmm.. I have found that the 40D fixed the 1/3 stop underexposure of the 400D but otherwise they are identical. What happens when you try to use ISO 800 or 1600? Noise? Do you shoot raw or jpeg? If jpeg, do you apply and EC?

1. I am using the same combinations of lenses on the 40D as on my old 30D and 400D (by the way, the difference with the 30D is only a very slight one, hence I have focused on the 400D)

2. I have very little noise on the 40D at 800 or 1600 compared to my old 400D - I shoot 80% jpg and 20% RAW depending on how much time I will get for PP work

I never use any EC as I have never found I needed it.

I'm starting to think I probably had a problem with my 400D - good thing I sold it to finance the 40D

I'll post some examples when I get home from work.

Helrain wrote in post #4099256
I'll post some examples when I get home from work.

That might help but I/m guessing that the 400 is a bit underexposed thus increasing noise. I did some side by side testing of my 400 and 40 and found that their noise characteristics were pretty much identical across all ISOs.

May I suggest that it just seems like the new camera does better? Maybe it does expose about the same as the older ones but it is so fantastic (in other ways) that it just seems to be a winner.