40D sensitive to underexposure?

I just picked up a 40D that I'm going to use as the sports complement to my 5D.

What I've seen is that if I underexpose at all at ISO of 400-500, (haven't shot higher ISO), I tend to get a bit more noise than I expected in the shadow areas. however, if I expose to the right, the noise diminishes rapidly.

My primary winter sports shooting is alpine ski racing so this presents somewhat of a problem. It is hard enough not to blow out the snow in bright sunlight, but then adding the need to expose to the right tends to make it difficult to not blow out the the snow anyhow.

Any tricks to reduce noise on the 40D or is it just that I'm spoiled by the 5D?

J

Just expose so you don't blow important highlights. If snow is dominant in the scene, you'll probably have to add +1 EC or so in any case. Take a couple of shots and adjust the EC or shoot manual. It's when you pull it up in post processing that you get most noise. Correcting exposure downwards in pp you don't get the noise problem, but you've got to protect important highlights.

BogongBreeze wrote in post #4901207
Just expose so you don't blow important highlights. If snow is dominant in the scene, you'll probably have to add +1 EC or so in any case. Take a couple of shots and adjust the EC or shoot manual. It's when you pull it up in post processing that you get most noise. Correcting exposure downwards in pp you don't get the noise problem, but you've got to protect important highlights.

I understand how to expose for snow. What I'm concerned about is that the noise in the shadows on the 40D at ISO400 or higher seems to be significantly higher than (by a long ways) than my 5D and even than my XT. I'm concerned that either (a) my 40D is abnormal (a problem) or (b) I'm missing some trick or subtelty in shooting high contrast scenes with the 40D. The noise is distressing and, I think, bordering on excessive.

I bought the 40D as a "poor man's MKIII" to shoot sports because the AF is improved and high burst rate. Up until then, the 5D had done well because of the hidden AF points and seemed better than the 20/30D. What I'm seeing, I think, is a very much less forgiving sensor - which is a problem in my application - given the high contrast shooting situations. Could be due to the *%(#$#$ stupid MP battle in cameras resulting in too dense sensors.

J.

I'd be interested to know the answer to that question too.

I think I've heard something about more noise with 1/3 stop ISO turned on, but that might have been for 5D. In any case, you may try turning 1/3 stop ISO off and see if you get better results.

That was exactly my finding when I used to own both bodies.
You'll hear people say "well, get the exposure right to begin with", but that's not even the point. It's when you either didn't or couldn't shoot to the right that this appears.

I agree with you 100%. The 5D seems to offer more margin for error than the 40D.

JohnJ80 wrote in post #4902518
What I'm seeing, I think, is a very much less forgiving sensor - which is a problem in my application - given the high contrast shooting situations. Could be due to the *%(#$#$ stupid MP battle in cameras resulting in too dense sensors.

J.

I don't think anybody realistically expects the 40D to perform as well as the 5D, even if there has been a lot of wishful thinking expressed in that regard. However, to hear you say that the 40D is worse than the XT is very surprising and contrary to my own experience. My 40D is definitely less noisy than my XT.
Are you using HTP? It can cause noise in the shadows and although it might seem like a good safeguard against blown highlights, I think an experienced photographer doesn't need it. Moreover, if you are shooting RAW, it is IMHO really worthless.

Not using HTP and shooting in RAW.

Maybe not worse than the XT for noise, but about the same is probably a better description.

As an example - Here's the original picture, originally underexposed one stop.

From what I see the color of the snow in your pics is not correct. It looks bluish/gray. This is caused by underexposing as you mentioned you are doing on purpose. As per a post above, when taking snow pictures you must add EC to your normal metering in order to get white snow. This should also take care of the problem with noise in the shadows that you have.
Gerry

I understand the EC issue and yes, these photos are underexposed (that was my original point). However, the amount of noise that shows up is excessive, IMO.

These are just the most recent example. i also have some examples that I cannot post from bright sunlight with a skier in a dark speedsuit. These were properly exposed (not at all underexposed) and there is still similar amounts of noise in the shadows (speedsuit/skiing - the interesting part). I think it has to do with dynamic range and the inability of the sensor to overcome the signal to noise ratio at the pixel level.

Also, it isn't possible to nail the exposure every time. Seems like one pays a big noise penalty for slight underexposure on the 40D.

J.

I think your 40D is normal. I don't have 5D, I just have 30D and XT to compare to my 40D. I find that it is easier to get a cleaner image with 30D and XT. 40D on its best is better than both, but you cannot be sloppy with exposure. 30D and XT have more margin for error in exposure.

I also found myself doing more noise ninja on 40D images than the other 2 especially for high ISO.

eel

JohnJ80 wrote in post #4901163
I just picked up a 40D that I'm going to use as the sports complement to my 5D.

What I've seen is that if I underexpose at all at ISO of 400-500, (haven't shot higher ISO), I tend to get a bit more noise than I expected in the shadow areas. however, if I expose to the right, the noise diminishes rapidly.

My primary winter sports shooting is alpine ski racing so this presents somewhat of a problem. It is hard enough not to blow out the snow in bright sunlight, but then adding the need to expose to the right tends to make it difficult to not blow out the the snow anyhow.

Any tricks to reduce noise on the 40D or is it just that I'm spoiled by the 5D?

J

Have to turned on highlight? It might give you better head room if you expose to the right. Its not going to fix noise if you underexpose but it might make it harder to over expose.

New Hobby wrote in post #4904354
Have to turned on highlight? It might give you better head room if you expose to the right. Its not going to fix noise if you underexpose but it might make it harder to over expose.

No it won't but thanks for the suggestion. I don't care of the snow if exposed properly, I'd like the racer to be. According to the manual, turning on HTP will protect the highlights at the expense of more noise in the shadows.

J

eelnoraa wrote in post #4904257
I think your 40D is normal. I don't have 5D, I just have 30D and XT to compare to my 40D. I find that it is easier to get a cleaner image with 30D and XT. 40D on its best is better than both, but you cannot be sloppy with exposure. 30D and XT have more margin for error in exposure.

I also found myself doing more noise ninja on 40D images than the other 2 especially for high ISO.

eel

Thanks - good information. Good news is I'm glad to know that this is a standard 40D so I don't have to work on sending it back. Bad news is that this is the noise that one gets.

I do have a tendency to underexpose - a hold over from the decades shooting slides. The 5D is very forgiving in this. I'll have to favor overexposing instead, it looks like. What I'll probably start doing is metering for the snow specifically. Then, if I use the HPT, it might work ok and not be a noise problem.

A little distressing to find this (actually, more than a little) and I'm a bit disappointed in Canon. One would think that over time the cameras would have a wider sweet spot rather than a narrower one. I really do wish the mfgs would get off this MP kick and work on usable and increasing IQ instead. This amount of noise at ISO500 - low ISO by 5D standards is really indicative of the problem.

This tells me that I need to start saving for a 1DMk3 so that with the larger sensor and its larger pixel sites is going to be much more forgiving of exposure issues. Exposure is always trickier with moving subjects in high contrast situations - as in most outdoor sports. Would be very helpful for this and I probably wouldn't be having this problem.

J.

40D underexposed
Interesting discussion. I too thought it was my camera, or something I was missing in this learning curve of my first DSLR!
I have just acquired a 40D, and in the last couple of days have had some difficulty getting the proper exposure, nearly all my outdoors winter shots from today were underexposed and had high levels of noise, nearly exactly the same as the photos that JohnJ80 has show us.
Honestly, my S3 iS in Program made delivers a sharper more vivid quality image the the 40D in the same ISO range. I am not yet used to thinking!
Review of the photos on the histogram shows generally a good balance, or a slight favor to the left in P and Auto, while the images are clearly underexposed 1/3 to 2 stops, and there is a loss of good detail.
Manual and shooting to the right with EC shall be my quest in the next bit, especially with all the snow in Ontario!


Love POTN folks!