Custom white balance confusion!

[sirhc_1]

Hi everyone!


I've been googling around for quite sometime now trying to find the answer on using "white card" or "gray/grey card" for achieving accurate white balance & exposure. Up to now I dont have the answers!.....When to use these cards? How do I properly set up my custom white balance reference via in-cam(Canon 40D)?[:'(]


I've read in other posts that you need to be in full auto mode whilst some suggested going full manual. I'm really getting frustrated as it's also a bit time consuming doing PP.


Another thing, someone has told me that you can actually assign a custom image for CWB by setting it up directly thru the cam's memory via software. He can actually adjust from AWB to CWB without having to set up the CWB image reference again & again.


Can someone please help?


***How do I determine if the photo I've taken is properly exposed & what is correct exposure BTW? thanks in advance guys![:'(]

[Chuck Lee]

<span style="font-family: Verdana; color: black; font-size: 9pt;"]A white card or grey card (18%) placed intothe scene will allow you to post adjust the white balance. You must first take a photo of the white/grey card in the lighting conditions of the scene you wish to balance. A grey card works best because it does not usually get over exposed. A white card can. If the white card gets over exposed in the sample photo then the image will be useless for white balance adjustment.<o></o>


<span style="font-family: Verdana; color: black; font-size: 9pt;"]The main reason for a grey card is to properly meter the light in a scene. It seconds as a good white balance tool. When your camera meters the scene it adjusts white to 18% grey. Try it. Take a white piece of paper and put it under a fairly good light sourcelike outside in daylight. Take a photo with the paper filling the scene. The resulting photo will be around 18% grey. This is another very large topic.<o></o>


<span style="font-family: Verdana; color: black; font-size: 9pt;"]OK, back to white balance with the 40D. Take a picture inside under incandescent light. Try to get something white or neutral grey in the scene. Review the image on the LCD and see what it looks like. Sometimes Canon's AWB does a really good job. Sometimes it doesn&rsquo;t. Usually, indoor shots look really warm and yellow.<o></o>


<span style="font-family: Verdana; color: black; font-size: 9pt;"]Now, go to the menu screen and select White Balance. If you don't know where it is then I strongly suggest you read then owners manual. Select White Balance and scroll around and set it to Custom. <o></o>


<span style="font-family: Verdana; color: black; font-size: 9pt;"]When it returns to themain menu scroll down one position to Custom WB. Select it. Scroll through the images and select the one you want to use to set the camera's white balance to. Once that is done and the Camera's WB is set to Custom, all photos taken under those lights will beproperly white balanced with that setting. <o></o>


<span style="font-family: Verdana; color: black; font-size: 9pt;"]Sometimes, that's a good thing. Other times it's not. Sometimes, you may want a photo to lean blue which makes it look colder or cool. Or, you may want it to lean warm or to the red side. That's why the camera allows you to manually set the white balance as well.<o></o>


<span style="font-family: Verdana; color: black; font-size: 9pt;"]White balance has another component that doesn't get talked about much. Color Deflection, and yes the 40D allows you to manually adjust that as well. CD pushes the photo green or magenta. You will see this deflection occur especially under fluorescent lights. Fluorescent lights have a green color cast so the color deflection will lean towards magenta in order to balance for it. When the 40D white balance is set to Fluorescent light the color deflection will automatically be pushed toward magenta. With all the new fluorescent types available today, that may not be the best setting.<o></o>


<span style="font-family: Verdana; color: black; font-size: 9pt;"]The main reason for proper white balance when taking photographs is to make sure the photos being taken are properly exposed. That is what the histogram shows. If the white balance for a scene is completely off, one of the color channels will clip and the histogram will display an overexposure. If blinking highlights are on,there may be a lot of blinking on the lcd do to the clipped channel displayed. This can result in making exposure adjustments that cause poorly exposed final images. <o></o>


<span style="font-family: Verdana; color: black; font-size: 9pt;"]The best thing is to get close. Programs like Picasa as well as Photoshop (though PS doesn't keep as simple) allow you to adjust the white balance of your final images. <o></o>


<span style="font-family: Verdana; color: black; font-size: 9pt;"]Picasa has the most direct and effective tool I've seen for jpeg adjustment. <o></o>


<span style="font-family: Verdana; color: black; font-size: 9pt;"]The final and most effective way to handle white balance is to shoot in RAW format. Raw processors allow complete control over the white balance, color deflection and exposure. In a nutshell, raw bypasses the in camera jpeg converter.<o></o>


<span style="font-size: small;"]<span style="font-family: Times New Roman;"]I hope this helped clarifies your confusion and welcome to the TDP forum.<span style="font-family: Verdana; color: black; font-size: 9pt;"]<o></o>

[sirhc_1]

Thanks Chuck for the info! []


I've already managed to adjust some custom settings for the cam. But that's the only trouble I am having---CWB! How do I set up a custom white balance using a gray card? Can you help me out do this accurately? I don't have any commercially produced cards. How to DIY gray card &amp; set it up as CWB?


Need help!

[Chuck Lee]

How do I set up a custom white balance using a gray card?

1) purchase a grey card or pack of two.... here is one place or for DIY, use a coffee filter over the lens. (be careful not to touch thefront elementwith the filter. I don't think it will scratch it, but safer than sorry.)No one said that the white balance photo had to be anything and that anything has to be in focus. (you may have to switch to manual focus temporarily to take the out of focus shot. I think the 40D will not shutter unless the AF is locked. Take a photo of the gray card in the the light of the scene or take a shot thru the coffee filter of the light in the scene.


2) Just as I said previously, Go to the camera menu and select White Balance then scroll around and select Custom. This sets the camera to CWB. Look at the LCD panel on top and the WB symbol should be custom not AWB. It's third in the list. There's AWB, Manual(represented by a "K") then Custom. (a little dot between two small opposing triangles)


3) Go to the menu and select Custom WB. Press the thumbwheel select button to set the CWB to the currently displayed image. If that's not the right image, scroll around using the thumbwheel until you get to the one you want to use. Once selected, your camera is set.


4) That CWB will be there until you set it to some other image. You can change to manual, automatic or any other setting andthat custom settingwill still be there to select at any time.