Help on avoiding colour casting appreciated - some examples

[simon007]

took some images of a friend of mine the other day,
mixed results, the wb can be difficult to get right
in certain situations.

Here you go, some images: 1st one original, 2nd with auto correction

1498114982

[Marko]

ohh these are strong casts....even the corrected version is very magenta.
Question 1 - are you shooting these with AWB (automatic white balance) - if not what balance are you using?
Question 2 - what is the predominant light source here (window light?) Are there additional light sources?

[Iguanasan]

I'd love to help but I'd have to know a little more about the reason for the colour cast. There's no EXIF information in the images so it would be good to know the following before trying to help.

1) Camera?
2) Did you use a flash?
3) What caused the orange cast? Was it the colour of the setting sun or was she in an orange room?
4) Is this a digital shot or a film shot scanned in?
5) How was your white balance set?

Also, try and post an image that is less than 275KB and less than 1025 pixels or the board software will resize it which makes it even harder to see what's going on.

[simon007]

Camera CANON 450D
White Balance ( trying different settings )
Digital photo resized for the forum
Bright sun, red carpect and mixed colours
tried to use on camera flash, slave flashgun
generally i mixed things to try and get a good outcome

[simon007]

Exif data

14984

below 2 images just showing the room used

1498614985

[Marko]

This is only part of the answer and what you have posted is only a small part of the exif data- we need to know what balance was used or this is just speculation on our parts.
This info is embedded in the digital file. I use the camera raw pluggin to see settings like this.

Bright sun is daylight and flash is usually balanced close to daylight so in that case auto white balance or a daylight setting would have been best for this image.
If you shot under a light source that does not at all match the setting you choose for the colour balance - then these completely off results make perfect sense....but we cannot help you decipher them.

What balance was used is ESSENTIAL to learn from errors. We can't tell you what you did wrong if you can't tell us the balance.
If you put the card in the camera, you should also be able to see what the balance used was by way of an icon that will likely indicate this. Consult your manual go this info if it isn't clear.

What seems clear to me is that this was shot under the wrong colour balance.....

"mixing to get a good outcome" will take you much longer to learn this concept imo than matching light source to colour balance.
Hope that may help.

[Marko]

To CORRECT these casts....shoot in RAW not jpeg as casts are easier to correct in Raw.
The image in shot 5 looks correctly balanced.

[simon007]

Would a high setting be a problem for WB?

[Marko]

what's a high setting? shutterspeed, flash-sync speed?
If so, not as far as i know.

If the olden days we shot film and it was balanced for the light source - this has nothing to do with anything other than the light sources in the image.
The same principal holds for digital as far as i know.

[kat]

Marko, do you have a podcast on auto-balance? I personally shoot in raw and honestly never play with my balance. I know I should but to be honest..even if I shot in auto-balance, it's not too often I get such a yellow balance.

[Iguanasan]

I have a Canon 450D as well (XSi) so I'm familiar with the camera and the settings. I use automatic white balance 99% of the time and the camera is usually pretty close. I can adjust the WB in post since I shoot RAW for the few times when the camera gets confused by the lighting in the room. Refer to page 90 of your manual for setting the white balance on your 450D.

What editing programs are you using? There should be a setting there that lets you save your EXIF with the photo or copy the EXIF to the clipboard or something. There's no EXIF in the images you are posting so something is stripping it out. As Marko points out, it's hard without that White Balance detail to figure out what the issue was.

[simon007]

I have a Canon 450D as well (XSi) so I'm familiar with the camera and the settings. I use automatic white balance 99% of the time and the camera is usually pretty close. I can adjust the WB in post since I shoot RAW for the few times when the camera gets confused by the lighting in the room. Refer to page 90 of your manual for setting the white balance on your 450D.

What editing programs are you using? There should be a setting there that lets you save your EXIF with the photo or copy the EXIF to the clipboard or something. There's no EXIF in the images you are posting so something is stripping it out. As Marko points out, it's hard without that White Balance detail to figure out what the issue was.

Iguanasan,

When Sunlight comes though windows the intensity often changes,
I used when taking the images, ON CAMERA flash ( with/out slave flashgun ),
sometimes just the flashgun on the camera ( ttl and manual mode ) bouncing the flash sideways, upwards.
I changed the wb balance to FLASH, SHADE to try and counter changes to room temp.
I currently using a free open source program to edit my images
PAINT.NET ( there masses of plugins for this software )
ADOBE Photoshop ( very costly ), alternatives maybe Corel Paint Shop Pro or Serif Photo Plus

When I transfer my images to the computer I just pop the SDHC card into my reader and copy it to another folder.

MARKO in regard ISO, a high one being 800.

[kat]

ISO 800 would give you noise (color noise for me on my camera) if anything. But that color noise wouldn't be the overall yellow.

[kat]

The first two images. Is the first one an automatic white balance or a changed one?

[Iguanasan]

Iguanasan,

When Sunlight comes though windows the intensity often changes,
I used when taking the images, ON CAMERA flash ( with/out slave flashgun ),
sometimes just the flashgun on the camera ( ttl and manual mode ) bouncing the flash sideways, upwards.
I changed the wb balance to FLASH, SHADE to try and counter changes to room temp.
I currently using a free open source program to edit my images
PAINT.NET ( there masses of plugins for this software )
ADOBE Photoshop ( very costly ), alternatives maybe Corel Paint Shop Pro or Serif Photo Plus

When I transfer my images to the computer I just pop the SDHC card into my reader and copy it to another folder.

MARKO in regard ISO, a high one being 800.

If you are not "married" to that particular photo editing tool, I'd recommend Gimp if you want to stay low cost (free). You can see more on a blog post I wrote for Photography.ca - Photo Editing On The Cheap by Glenn Euloth | Photography.ca (http://www.photography.ca/blog/2011/03/29/photo-editing-on-the-cheap/)

It is difficult to suggest changes until we know exactly how each shot was taken. For instance you mention the flash bounced sideways. If you bounced flash off the red brick wall that might account for some colour cast. If you set the WB to FLASH and then shot with mostly sunlight through the window that might account for it as well.

You might consider just trying the following and check your results. Try to set up the same shot... same time of day, etc. to get the lighting conditions as close as possible to the original. Shoot in AWB mode and then try again without making any other adjustments other than the white balance.

Also, if you could post the original, un-edited, JPEG image somewhere (or do you shoot RAW?) then we can look at the EXIF in the file and see most of what we need to see.

[simon007]

original photo, no editing/resizing

14987

[Iguanasan]

Gaak! Still no EXIF. Marko, does the board software trash the EXIF when it resizes? Hmmm... If you want to track this down further, Simon you can email me the image. Use my handle, iguanasan. Then address it to that at gmail. (sorry, trying to be cryptic to avoid the SPAM bots). I hope that it makes sense.

[Marko]

Board software does not strip exif data as far as I know....but none of my Chrome extensions are working these days - so I'm having a pain with this also.

Simon - Just put the card back into the camera if the file is still on the card. Then look at your manual to figure out how to read the exif data. 800 iso has nothing to do with colour balance. To me this cast is severe enough that if I were a betting dude, I'd bet you simply forgot which wrong white balance setting you played with for this image.

Kat - white balance podcast is a great idea. On the list it is.

[simon007]

Thanks everyone for your input.......

Found this site/url.........

last image on this page, shows issues with tungsten.......

White Balance Examples (http://www.kenrockwell.com/tech/white-balance-examples.htm)
http://www.kenrockwell.com/tech/whitebalance.htm#application
http://www.kenrockwell.com/tech/whitebalance.htm

The other links provide a nice read

[Iguanasan]

Here's the EXIF... IrfanView is a free download which lets you copy the EXIF to the clipboard... handy feature...


Make - Canon
Model - Canon EOS 450D
Orientation - Top left
XResolution - 72
YResolution - 72
ResolutionUnit - Inch
DateTime - 2012:04:02 10:37:55
YCbCrPositioning - Co-Sited
ExifOffset - 196
ExposureTime - 1/100 seconds
FNumber - 3.50
ExposureProgram - Shutter priority
ISOSpeedRatings - 800
ExifVersion - 0221
DateTimeOriginal - 2012:04:02 10:37:55
DateTimeDigitized - 2012:04:02 10:37:55
ComponentsConfiguration - YCbCr
ShutterSpeedValue - 1/99 seconds
ApertureValue - F 3.51
ExposureBiasValue - 1
MeteringMode - Partial
Flash - Flash not fired, compulsory flash mode
FocalLength - 50 mm
UserComment -
SubsecTime - 41
SubsecTimeOriginal - 41
SubsecTimeDigitized - 41
FlashPixVersion - 0100
ColorSpace - sRGB
ExifImageWidth - 2256
ExifImageHeight - 1504
InteroperabilityOffset - 9506
FocalPlaneXResolution - 2569.48
FocalPlaneYResolution - 2575.34
FocalPlaneResolutionUnit - Inch
CustomRendered - Normal process
ExposureMode - Auto
White Balance - Manual
....

So, from this it looks like your white balance was set to some manual setting whereby it could have been set to anything which explains the colour cast. Since you are shooting JPG mode you can't really fix it though you can adjust it. JPEGs are already "baked" but if you were shooting RAW, a fair bit more complicated and I wouldn't switch unless you are very comfortable with it, you can set the white balance after the fact though it's always better to get it right in-camera.

[simon007]

Thanks Iguanasan,

I currently use a free program for limited correction
PAINT.NET - it has many plugins designed by it's users.
ie COLOUR MIXER, COLOUR BALANCE, WHITE BALANCE.

to finish this subject off, here 3 images, 2 with a bit of correction I attempted with PAINT.NET. They don't seem too bad, can photoshop
and professional software do any better with the colour balances?



149911499214993

[Marko]

If shot 3 is the original, to my eye it's the best of the 3. It looks natural to me.

I do see that there are some skin blemishes in shot 3 that are hidden with the colour cast in shots 1 and 2 - but a colour cast is not the correct way to soften skin.
Softer light is the best way, avoid sidelight which reveals skin texture....then there are pluggins and the use of the sharper/blur tools.

Photoshop is simply AWESOME. You can learn it easily in a week with online tutorials that are free or at Lynda.com or KelbyTraining.com | The Leading Provider of Education for Photography and Creative Professionals Worldwide (http://kelbytraining.com/) for about 25.00 a month to watch fab video tutorials.
There is a beta version of Photoshop CS6 that is out now that is FREE. I have been using it now for 2 weeks and it works very well. Adobe Labs | Previews, prereleases and beta software from Adobe (http://labs.adobe.com/)

Both shots 1, 2 are magenta to my eye.
Hope that may help.

[Andrew]

Two words.....Grey Card.

If you are trying to understand WB you need to be aware of the basics. What different light sources do(alone and combined) and what you are seeing with each change you make. You're not there yet. "mixed things to try and get a good outcome" is your problem. By the results I'd have to guess you also changed settings other than WB.

Put everything back to factory defaults and start over....slowly. Understand what the camera does and what the effects will be before you make the option selections.

[Iguanasan]

Two words.....Grey Card.

If you are trying to understand WB you need to be aware of the basics. What different light sources do(alone and combined) and what you are seeing with each change you make. You're not there yet. "mixed things to try and get a good outcome" is your problem. By the results I'd have to guess you also changed settings other than WB.

Put everything back to factory defaults and start over....slowly. Understand what the camera does and what the effects will be before you make the option selections.

Great advice!

[simon007]

Two words.....Grey Card.

If you are trying to understand WB you need to be aware of the basics. What different light sources do(alone and combined) and what you are seeing with each change you make. You're not there yet. "mixed things to try and get a good outcome" is your problem. By the results I'd have to guess you also changed settings other than WB.

Put everything back to factory defaults and start over....slowly. Understand what the camera does and what the effects will be before you make the option selections.

I do understand basic camera funtions / principles.

ie LOW light = raise ISO, slow shutter speed down, widen aperture ( low f number ).
a slower shutter speed with raised ISO and wide aperture
will make image overexpose
very slow shutter speeds will blur image.........

is this correct?

If so I will need to learn more.
The GREY CARD seems a good idea,
What GREY CARD should I buy and how do I use it properly?
Most advice so far when I have searched the net seems to suggest
a GREY CARD rated at 18% ( some suggest 3 colour cards of WHITE, BLACK and GREY ).

Simon

[simon007]

I have read up on USING a grey card.
Tell me if I have got it right.
1 - Take a photo with Grey card in centre of image. ( use METERING mode (any ) or AF manual focus to FOCUS on a point where the GREY card is )
2 - Select MENU - Custom WB - Select photo with GREY card.
3 - Select WB on camera and select Custom WB.

Is this right?

By the way is there much difference between METERING modes and AF AUTO / Manual options?
It seems both could be used for custom WB.

[simon007]

I have just found that LIVE VIEW is a good way of setting the WB.
It's shows what the camera sees and allows me to change WB and see
the differences there and then.

Simon

[Marko]

Sorry about the formatting here....


I do understand basic camera funtions / principles.

ie LOW light = raise ISO, slow shutter speed down, widen aperture ( low f number ).
a slower shutter speed with raised ISO and wide aperture
will make image overexpose
very slow shutter speeds will blur image.........

is this correct? This is partially correct. When the exposure is correct, there is no over-exposure. very slow shutter speeds won't blur everything unless you are handholding the camera at a very slow shutter speed. Put it on a tripod and anything that does not move (like a rock) should be sharp

If so I will need to learn more.
The GREY CARD seems a good idea,
What GREY CARD should I buy and how do I use it properly?
Most advice so far when I have searched the net seems to suggest
a GREY CARD rated at 18% ( some suggest 3 colour cards of WHITE, BLACK and GREY ).

Simon


I have read up on USING a grey card.
Tell me if I have got it right.
1 - Take a photo with Grey card in centre of image. ( use METERING mode (any ) or AF manual focus to FOCUS on a point where the GREY card is )
2 - Select MENU - Custom WB - Select photo with GREY card.
3 - Select WB on camera and select Custom WB.

Is this right? This is correct in principle, the steps may vary from camera make to camera make. But you can ALSO just use the grey card to determine the exposure, in fact that would be its primary use and the reason it was created.

By the way is there much difference between METERING modes and AF AUTO / Manual options?
It seems both could be used for custom WB. There is a big difference between metering modes but they are given different names according to what camera you have. Spot metering for example is vastly different than the default metering setting that comes with the camera - this should be well explained in your camera manual. Auto AF, stands for auto-focus which has nothing to do with exposure. Focusing manually also has nothing to do with exposure. But the metering modes available to AF or manual mode should be the same

Hope that may help -

[simon007]

ohh these are strong casts....even the corrected version is very magenta.
Question 1 - are you shooting these with AWB (automatic white balance) - if not what balance are you using?
Question 2 - what is the predominant light source here (window light?) Are there additional light sources?

--------

MARKO and all,

Sorry to continue this thread ( if your getting bored )

How would you more seasoned campaigners had done this room.
Both with the equipment I shall list and your choice of equipment.

The 3rd and 4th images on page 1 are what the room looked like and the window
is where the Sun beamed in ( mixture of brightness/ intensity ).
I used my Canon EOS 450D with kit lens and briefly with my 50mm 1.8 Prime lens.
I had a Jessops ( 3rd party ) Flashgun with bounce flash SWIVEL and Up/Down upto 90 degrees,
flash power rating of 34m. I did try to use the flash both on the camera and off ( slave ) plus
at times both ON-camera and SLAVE ( same time ).

Simon

PS: The room was probably a bit lighter than the images in 3 and 4 show.