Will the owners of Canon SD600 please stand up?

[HuiYeng]

Hi,
I have a SD600 for less than 1 year, I've noticed that all my winter hiking pictures to have a very bad color balance on them. For example, see this pic, notice that the right side have a cooler tone than the rest of the pictures? If you look at all my winter hiking pictures since last year you'll see all pictures that capture snowy trail to have this problem, some more serious than other.

Am I being picky? I have already made my peace with the vignetting effect on them, now this inconsistent tone on the pictures really bother me. Is it just me, just my camera, or do other SD600 owners have the same problem but have made their peace? Serenity now!

See also this and this.

Thanks in advance.

 

[Tom Rankin]

Most cameras render the subject as neutral gray. If you want the snow to look really white, you have to deliberately over-expose the shot. I'm not familiar with this particular camera, but there are at least 2 ways this can be done. One is to manually choose the shutter speed, and the other is to adjust the white balance.

 

[dvbl]

Maybe I have a poor quality monitor....but I don't see it.

Edit: some cameras even have a "snow" setting on them

 

[HuiYeng]

Hmm.. if the whole picture is consistently off white, I agree with you that I can either over expose the photo or use the Level in PhotoShop to correct it. But in my case (at least from what i can see), my pictures render inconsistent color temperature.

The pictures I link on the first post were captured using Snow mode, which do not allow manually adjust the white balance. I had tried Manual mode with AutoWhiteBalance as well as Sunlight, all came out with the same undesired result.

Something wrong with my eyes...??

 

[DougPaul]

I have a SD600 for less than 1 year, I've noticed that all my winter hiking pictures to have a very bad color balance on them. For example, see this pic, notice that the right side have a cooler tone than the rest of the pictures?

I don't see it. I also looked at the actual pixel (numerical) values. It isn't there--the color of the snow is the same on both sides.

BTW, color balance should affect the entire image equally--if it varies across the image, you have something wrong.

See also this and this.
.

Same here--again the color of the snow is the same on both sides as judged by the numerical values at some sample pixels.

My best guess is that what you are seeing is a problem with your monitor or the environment that your monitor sits in. Pretty much anything stronly asymmetric about the lighting or color scheme near your monitor could potentially affect your color perception as a function of location on the monitor.

Try the following:
1. Look at your images on another monitor.
2. Flip an image left-for-right and view it on your monitor. See if the problem stays with a location on the image or a location on the monitor.

BTW, IMG_1444.jpg (the second one) is well exposed, the other two (1st and 3rd) are underexposed, as judged by the histogram.

Doug

 

[HuiYeng]

BTW, color balance should affect the entire image equally--if it varies across the image, you have something wrong.

That's what I'm afraid of, either it's something wrong me, or my camera which its warranty expire in 1.5 month.

Try the following:
1. Look at your images on another monitor.
2. Flip an image left-for-right and view it on your monitor. See if the problem stays with a location on the image or a location on the monitor.

Doug

Yes, I looked at them on both CRT and LCD monitors, I can see the color variation on both displays.

FWIW, I uploaded the full size version here.

Hmm.. Thanks anyway.

 

[David Metsky]

It's possible that you have a sticky shutter curtain. This would only show up at high shutter speeds and something like snow could make it appear much more apparent. Do you have the EXIF data for those shots?

I don't see that affect on my SD300, which is roughly the same camera.

-dave-

 

[Grumpy]

I do see what appears to be some slight vignetting, but don't see the color variations you wrote about.

BTW I don't find the vignetting distracting. But then, I'm one of those photogs who routinely burned in the corners of B&W prints, just a touch, to produce a similar effect (it helps keep the viewer's eye in the frame).

G.

 

[DougPaul]

Yes, I looked at them on both CRT and LCD monitors, I can see the color variation on both displays.

Then there is still your eyes...

Try the L-R flipped image--it should help you eliminate a number of possibilities.

Doug

 

[DougPaul]

It's possible that you have a sticky shutter curtain. This would only show up at high shutter speeds and something like snow could make it appear much more apparent. Do you have the EXIF data for those shots?

Shutter problems should show up in intensity, but not as color shifts.

Doug

 

[kmorgan]

There's quite a lot of trouble in this picture. I adjusted the levels to enhance the differences and even adjusting for vignetting there are problems.

Here's the photo with levels adjusted:



and with lens correction for vignetting there are still noticeable areas of different levels and color cast:



If the camera's under warranty I'd take it back.

Kevin

PS. I just found this review: http://www.imaging-resource.com/PRODS/SD600/SD600A.HTM and there is a mode for snow and foliage, etc. Still, I think you have a problem. -- KJM

 

[DougPaul]

Don't forget that snow that is not in direct sunlight will be lit by light of different colors. (For instance shaded postholes on a sunny day can look yellow and blue.)

A controlled way of looking at this issue would be to photograph a target (eg sheet of white paper) or part of a target in consistent lighting with fixed camera settings. If the target is placed on the left, center, and right of the frame, then the numerical values for pixels representing the same part of the target can be compared. The only thing that will be different will be the location in the camera image.

Doug

 

[HuiYeng]

and with lens correction for vignetting there are still noticeable areas of different levels and color cast:

Whew, so I'm not crazy, not completely anyway... The pictures were shot with Snow mode. I'm OK with the vignetting too, it gives the pictures kinda vintage look, besides it is easy to crop out. The color variations really bother me.

Don't forget that snow that is not in direct sunlight will be lit by light of different colors. (For instance shaded postholes on a sunny day can look yellow and blue.)
Doug

The problem is the color variation if occur (or visible) it always on the right side of the picture, regardless of objects in the shadow or not.

Here are the EXIF info for all 3 of them (sorry, long list):

File Name IMG_1485.JPG
Camera Model Name Canon PowerShot SD600
Shooting Date/Time 04/10/07 14:02:13
Shooting Mode Snow
My Colors Mode Off
Tv (Shutter Speed) 1/800
Av (Aperture Value) 5.6
Light Metering Evaluative
Exposure Compensation 0
ISO Speed Auto
Lens 5.8 - 17.4mm
Focal Length 5.8mm
Digital Zoom None
Image Size 2816x2112
Image Quality Superfine
Flash Off
White Balance Auto
AF Mode Single AF
Parameters
Contrast Normal
Sharpness Normal
Saturation Normal
Color Space sRGB
File Size 2206KB
Drive Mode Single-frame shooting
Owner's Name

File Name IMG_1469.JPG
Camera Model Name Canon PowerShot SD600
Shooting Date/Time 04/10/07 13:32:31
Shooting Mode Snow
My Colors Mode Off
Tv (Shutter Speed) 1/1500
Av (Aperture Value) 5.6
Light Metering Evaluative
Exposure Compensation 0
ISO Speed Auto
Lens 5.8 - 17.4mm
Focal Length 5.8mm
Digital Zoom None
Image Size 2816x2112
Image Quality Superfine
Flash Off
White Balance Auto
AF Mode Single AF
Parameters
Contrast Normal
Sharpness Normal
Saturation Normal
Color Space sRGB
File Size 2024KB
Drive Mode Single-frame shooting
Owner's Name

File Name IMG_1444.JPG
Camera Model Name Canon PowerShot SD600
Shooting Date/Time 04/10/07 12:24:54
Shooting Mode Snow
My Colors Mode Off
Tv (Shutter Speed) 1/1000
Av (Aperture Value) 5.6
Light Metering Evaluative
Exposure Compensation 0
ISO Speed Auto
Lens 5.8 - 17.4mm
Focal Length 5.8mm
Digital Zoom None
Image Size 2816x2112
Image Quality Superfine
Flash Off
White Balance Auto
AF Mode Single AF
Parameters
Contrast Normal
Sharpness Normal
Saturation Normal
Color Space sRGB
File Size 2430KB
Drive Mode Single-frame shooting
Owner's Name

Thanks for all your feedbacks, I think I'll contact Canon.

 

[DougPaul]

FWIW, I uploaded the full size version

I made some comparisons of the foreground snow on the left and right--the colors are essentially the same (as judged by the numerical values at each pixel). I don't see any difference by eye either.

BTW, the standard color temp of digital cameras is 6500K. Most computer displays are set around 9000+K--far too blue. Setting a proper color temp (6500K) on your display (if you can) might help.

Doug

 

[MichaelJ]

I see color change as a result of the vignetting on the right-hand side. There appears to be a slight cast towards blue. My eyes see it on my calibrated LCD cinema display in the original and in kmorgan's revised images.

The center foreground has very balanced color, pixels are 98% red, 98% green, 96% blue. As we go to the right the balance changes to 95-98-99 or even 95-100-100.

 

[Grumpy]

Playing with your original image in Photoshop, I detected a powerful RED component in the scene, which seems to be very characteristic of the (many) underexposed digital shots I’ve dealt with in recent years. (I would have expected a scene like this to lean heavily toward BLUE, with relatively less RED.)

There also was a strong BLUE component, which would be expected in this scene, given the subject (snow) in daylight. Adjusting Levels by reducing both the expected BLUE and the excess RED until the vignetted area to the right looked more “neutral” left a REDDISH tinge in the central part of the frame, which I also detect in the corrected image posted by K. Morgan.

I also played a bit with luminosity, in Lab Color, selectively changing the Brightness and Contrast in the vignetted area to achieve what looked like a balance across the frame. Converting back to RGB, I again saw a REDDISH tinge in the central part of the frame.

The more I look at this, the more I think the vignetting lies at the core of the the color shift problem you perceive. Vignetting in this case would be slight underexposure, which would cause a slightly exaggerated (more saturated) color rendition in the vignetted (underexposed) areas. Remember, we should expect a strong bias toward BLUE in this kind of scene.

So the question in my mind is, “what is causing the vignetting?”

Are you using an add-on lens shade and/or filters? If the answer is “yes,” have you tried shooting a scene both with and without these accessories to see if they are creating the vignetting?

If the answer is “no,” or if you have run the test and concluded the accessories are not causing the vignetting, then it is legit to ask: Is it something to do with the design or manufacturing mechanics and optics of the camera? Or is it something to do with a defect or quirk in the sensor?

Anyway, that’s how I see this.

You’ve posed a really interesting problem here.

G.

 

[DougPaul]

Following Grumpy's lead, I took the sample pics and simply turned up the color saturation.
http://mysite.verizon.net/dbpwebjunk/7summits/x_1444.jpg
http://mysite.verizon.net/dbpwebjunk/7summits/x_1469.jpg
http://mysite.verizon.net/dbpwebjunk/7summits/x_1485.jpg

These suggest that it is not just a corner problem--it is a side vs center problem. Both sides are significantly bluer than the center.

Also quite a bit of blue noise. (Inexpensive digital cameras tend to show more blue noise than the other colors, particularly in shadows.) What is your ISO setting (not in your exif info)? High settings tend to have more noise. In general, it is better to use the lowest ISO setting that you can (particularly with P&S cameras with small sensors).

It would be helpful if you took a picture of a white piece of paper (several sheets in a stack would do better so that nothing shows through) with uniform lighting and the camera in a snow setting. Then we could examine the image without the details of a scene getting in the way.

Doug

 

[Grumpy]

Doug Paul’s experimentation provides some interesting images and an important observation about the vignetting effect: “not just a corner problem--it is a side vs center problem."

Looking at the metadata provided on the three original pix, I see that all three were shot at f/5.6 (but shutter speeds varied) at the same focal length (5.8mm with a 5.8mm – 17.4mm zoom lens). The frame format apparently is slightly rectangular (2816 x 2112 pixels – about a 4:3 ratio, width to height).

This would account for the evidently greater vignetting effect at the L-R sides as compared to the top and bottom of the image if the vignetting is due to some mechanical interference (filter ring or lens shade, for example). We would expect to see these effects most at the short end of the zoom range.

So, I renew my questions about use of filter and/or lens shade, but add to it a question about whether the vignetting occurs (or is as great) at the longer end of the zoom range.

G.

 

[HuiYeng]

Hi Grumpy,
no, i didn't use any lens on the camera. I read few reviews before I bought the camera, the (minor) vignetting effect is a known issue for this camera. After much research and comparison, I still decided to go with this camera because based on the reviews, it is very responsive and has nice picture quality. I have to say, i have been very happy with it in general, just this blue tone problem bother me.

That's why I'm hoping other sd600 user can share their pictures for me to compare. Just wanna find out is the "problem" by design, or I bought an bad apple. So, i did a search at dpreview.com, and found some pictures from a member, also show slight blue tone on the right, not as bad as mine, but it's there. By looking at her pictures collection and compare to mine, it does seems that all the underexpose pictures have visible (to some) blue tone on the right.

But then if the camera is doing the right thing, pictures shouldn't be underexposed, after all I did use the Snow mode for snow scene. I'll try again this weekend, using both Manual and Snow mode, and overexpose the pictures. Also avoid using wide angle to reduce the vignetting effect.

I'll report back. Thanks for all your feedbacks and experiments, I really appreciate that.

Doug, the Snow mode do not allow manual ISO setting. Hmmm... for a point and shot, I actually think Canon SD series are not cheap.

Thanks all!

 

[Grumpy]

... if the camera is doing the right thing, pictures shouldn't be underexposed, after all I did use the Snow mode for snow scene.

Snow scenes in relatively flat light (under overcast or in shaded areas) present one of photography's most vexing exposure problems. One of the worst things you can do is overexpose, which blocks up (or in digital terms, blows out) the highlights. This will be aggravated further by trying to boost contrast.

Your camera metering and exposure control system actually seems to have handled this problem quite well. I suspect the controlling algorithms are on the conservative side, leaning toward underexposure and a flat (lower contrast) image that leaves some possibilty for improvement by tweaking with a tool like Photoshop. In fact, that's exactly how I see the original image you posted -- flat, and very slightly dark, or dingy, but with textural details preserved in the snow.

How does the camera perform on scenes with a greater range of colors and at longer zoom setting?

G