Is this normal? - DPChallenge Forums

02/23/2009 11:16:28 AM · #1

My fellow 5D MKII shooters, or really anyone out there, is this normal?

I know this is underexposed (-2 EV), as it was going to be used for an HDR shot, but is this much noise at ISO 200 normal? The noise is still visible at 0 EV, but not as much, see other example below.

I already have a warranty return set up with Canon, but don't want to send off my camera if I don't have to. Some people on another forum say that it is not normal, while others are reserving judgement because it was an underexposed shot. Personally I don't think this would be normal, especially for a 5D MKII. So what do you all think? Should I send it in?

Bebe

Canon EF 24-70mm f/2.8L USM

02/23/2009 11:19:05 AM · #2

What kind of crop is this on the original?

I don't have the MKII, but I think I'd be very disappointed if I bought it & saw that kind of noise.

02/23/2009 11:28:22 AM · #3

Originally posted by Bebe:

What kind of crop is this on the original?

I don't have the MKII, but I think I'd be very disappointed if I bought it & saw that kind of noise.

100% crop on both shots, as they were taken at different focal lengths. They guy on the phone yesterday said that it shouldn't be happening .... just want to triple check before I lose my camera for a week or more.

k4ffy

02/23/2009 11:34:14 AM · #4

nope, doesn't look right. 200 ISO is pretty much butter smooth for me, even at 100% crop.

02/23/2009 11:34:27 AM · #5

A couple observations: anytime you underexpose to that degree you're going to have noise. It's inevitable. And that exposure you're showing us is useless for an HDR merge anyway: the darkest image in your merge should be one that properly renders the bright areas in your shot, and the bright side of the structure is like 2 stops underexposed there.

Second observation: for an HDRI merge, the program is not going to be using the information from the darkest areas of the darkest image anyway, so noise in the dark areas is not a problem. The darkest image is what the merge takes the *highlight* information from.

Whether what you're seeing represents a problem with a 5D I have no idea, but it definitely represents a problem with your photographic technique: the darker of those images has no reason for existing in your workflow at all.

R.

02/23/2009 11:38:03 AM · #6

Originally posted by Bear_Music:

Thanks for the tip Bear. Although, there are much brighter highlights in the areas you can see, so I still think that this shot would work, minus the noise.

02/23/2009 11:53:35 AM · #7

Originally posted by lifeafter2am:

Thanks for the tip Bear. Although, there are much brighter highlights in the areas you can see, so I still think that this shot would work, minus the noise.

Can you post the entire image of that dark frame so I can see what you're dealing with? Another aspect of the problem, basically, is that the blue channel almost ALWAYS has the most noise of any of the channels. You can sometimes profitably do noise removal on the blue channel alone, then merge the channels back together, but you really shouldn't be having that problem with a 5D, I wouldn't think, with proper sky exposures?

Still, bear in mind that the shadowed side of the building is illuminated with reflected blue light from the sky...

R.

Message edited by author 2009-02-23 11:54:35.

Nikon AF Nikkor 50mm f/1.8D

02/23/2009 12:18:28 PM · #8

Originally posted by Bear_Music:

Originally posted by lifeafter2am:

Thanks for the tip Bear. Although, there are much brighter highlights in the areas you can see, so I still think that this shot would work, minus the noise.

Can you post the entire image of that dark frame so I can see what you're dealing with? Another aspect of the problem, basically, is that the blue channel almost ALWAYS has the most noise of any of the channels. You can sometimes profitably do noise removal on the blue channel alone, then merge the channels back together, but you really shouldn't be having that problem with a 5D, I wouldn't think, with proper sky exposures?

Still, bear in mind that the shadowed side of the building is illuminated with reflected blue light from the sky...

R.

I had to scale down the image some, but the link is a much larger size of that image. What kills me is that it is present in the 0EV shot as well, which just shouldn't happen IMO. I am going to send it in I guess. Seriously though, thanks for the HDR tips, I am brand-new to doing HDR stuff, it's a whole new world for me. :-)

//photography.lifeafter2am.net/albums/userpics/10001/Leu-1499%7E0.jpg

kirbic

Canon EOS R5

Canon RF 24-70 f2.8 L IS

02/23/2009 03:26:43 PM · #9

FWIW, I'm not saying there is definitely nothing wrong with the camera, but I do have doubt. The 0 EV crop you posted has a nice chunk of rather uniform sky, so I loaded it into Photoshop, selected a 200px square area (40,000 pixel sample) and noticed that most of the noise was in the red channel. If you do this, look at the width of the histogram for each channel. A uniform, noise-free patch of sky would be a single, vertical spike; notice how the Red spike is wider than the other two? Also, notice how far left of the other two it is? The Red channel is pretty dark, and therefore has more noise.
Now, that said, I don't know how this image was acquired? Was this a JPEG capture, or a RAW image? If it was a JPEG capture, what camera settings relating to color and contrast, e.g. what picture style and white balance? If RAW, was the exposure slider on "0" or not, and were any other major adjustments made to the photo during development?

Prash

Nikon D90

02/23/2009 04:11:42 PM · #10

I am no expert in 5D MKii.. but from a general imaging point of view, lower the light/exposure, higher the noise. Because there will be insufficient information available to the photo sensors to accurately recreate the scene being captured. Different vendors have different implementation of what to do in such a case. Some may average inforation from neighboring pixel cells... others may leave it prety close to what the cells estimate. Canon is known to leave the raw data pretty much untouched except for some anti-aliasing pre-processing, which is commendable.

In short, this might very well be expected from such an underexposed shot and the lighting conditions. No sensor is perfect. I can bet that even the most expensive photo sensor will have a exposure level limit line below which, if under exposed, it will show noise. The beauty is in how well the imaging system works to avoid such noise at normal shooting conditions in human-visible spectrum. I just dont know if a 5d should be expected to be fairly noise-less in the example you posted.

Nikon AF Nikkor 50mm f/1.4D

02/23/2009 04:18:10 PM · #11

Thanks for all the advice guys and girls! I just sent it off to Canon, I figured the worse they can tell me is that this is normal and just send it right back. It's under warranty, and I shipped it via my work account, so it really doesn't cost me anything.

I will let everyone know what they say.

warriorwriter

Nikon D700

02/23/2009 04:19:16 PM · #12

I own a D700, so low light noise is never a problem for me. Just thought I'd brag.

Prash

Nikon D90

Nikon AF Nikkor 50mm f/1.8D

02/23/2009 04:21:46 PM · #13

Originally posted by warriorwriter:

I own a D700, so low light noise is never a problem for me. Just thought I'd brag.

;-)

02/23/2009 05:09:54 PM · #14

Dude, that's a SERIOUSLY underexposed image you posted up in the large size. It's way off the charts underexposed, there's no reason for it to exist. It's not POSSIBLE for there not to be noise in that sky, that underexposed. I did a quick leveling on it, and this is about what the bright areas should look like for your HDRI merge:

And that's like TWO STOPS more exposure than the sample image. And if you used one like this foe dark end of your range, then there'd be a LOT less noise in the sky; and remember, the HDRI merge won't even USE the blue sky from this exposure, so it's not an issue at all. Of course even in this leveled version, the sky is showing bunches of noise, but that's because you locked it in with your dramatic underexposure. You basically underexposed the sky portion by at least three, and maybe FOUR, stops.

It's the nature of the beast that this will give you noise, it's unavoidable; even with that damned D700... :-)

R.

03/04/2009 01:02:19 PM · #15

And the verdict is .................. yes it was severely underexposed (didn't use the right metering mode), but they did also replace the DIGIC chip in the camera as well. I will have my camera back today! :)

03/04/2009 01:23:30 PM · #16

Cool! Maybe there WAS something wrong with the chip as well, sort of a double whammy. Now study on the intricacies of HDRI exposures (PM me is you wish) so you can do the best possible job.

R.

Canon EF 24-105mm f/4.0L IS

03/04/2009 05:34:00 PM · #17

Ok, so got my camera back today and something weird is showing up. I was shooting some and went to upload the shots to the computer and it seems that the numbering on the memory cards started at 9958. So why is this weird? Well it was, and is, set to continues numbering and I sent it to Canon with less than 3500 shots on it. Did they really take that many shots or is something else happening?

Five_Seat

Canon EOS-6D

03/04/2009 05:49:56 PM · #18

I have no idea, its probabky some programming tweak they did...But your story reminds me the scene in Ferris Bueller's Day off when Ferris drops the Ferrari off at the parking garage in downtown Chicago. lol.