Friday, June 17, 2011

Photography - Exposure and Colour Balance

June 17, 2011


I thought that I'd change subjects today. I have another blog (http://photoshop-for-e-bay.blogspot.com/) that I started at the same time as this one. However, it doesn't get the readership as this one does.

The other site is all about taking better photos for presentation on E-Bay. Consequently because of the lower readership, I decided to add it into this blog.

Of course, for those who aren;t interested, simply go to my other regular toy articles.

1. Exposure
It's unbelievable how many terrible photos that I see on E-Bay for toy listings. 

They're often out-of-focus, poorly lit, underexposed, and are off in colour.

Below are a series of exposures ranging from underexposed to overexposed.

The way you check to see that you have correct exposure is to make sure the brightest areas of your image (photo) have detail. Detail is a photographic term simply meaning the texture or information that a part of the image has.

Exposure 1
Overexposed- meaning that too much light has exposed the CCD of your digital camera
Notice that the Hubley Kiddietoy steamer-pumper is totally white,and you cannot see the detail or shape of the part.

Exposure 2
Properly Exposed- meaning that the correct amount of light has exposed the CCD of your digital camera.
Most of the bright areas called highlights can be seen to have their detail.


Exposure 3
Properly Exposed- meaning that the correct amount of light has exposed the CCD of your digital camera
The bright areas called highlights can be seen to have bette detail than exposure # 2. However, the red areas are going too dark!



 Exposure 4
Underexposed meaning that there is not enough light to expose the CCD of your digital camera.
Detail is being lost everywhere.
 Exposure 5
Badly underexposed meaning that there is not enough light to expose the CCD of your digital camera.
Too much detail is being lost everywhere.

2. Colour (Color-US) Balance

Colour balance simply means that you have accurate colour. Most of you are already familiar with a digital camera,  so you know that if you don;t set your camera for the light source (tungsten, daylight, overcast, etc.) you don't get proper colour.

The colour of a photo can also be affected by the walls of the room where you are taking the photo. 
So, even if you have the right setting on your camera, your final photo may be off-colour!

Before digital photography, there was something called a gray card (grey). Placed in the photo as an exposure image (Shot or photo), you would use it to see if it went "off-colour".  It mostly however was used for proper exposure. If you overexposed it it would go too light, and if underexposed it would go too dark.

In the digital camera era, there are new "aids" to help with both exposure and  colour-balance.

Below are some of the "aids".

I'm not going to bore you with too much detail, but they're simple to use when you have a photo-editing software. If Photoshop or Claris is too expensive, you can always use Picassa (free from Google). You can also use the simpler software that usually comes with your camera (camera, Nikon, Sony....) 



An old Kodak Book. It contains a gray card that can still be used.
As these books were written for film cameras, they can be purchased inexpensively on E-Bay.


Moderately Expensive if you're not a pro.
All of these "aids" work with Photoshop or other image-image-editing software.
A gray shade will read "neutral" in Photoshop. There are equal proportions of red, green and blue to make the gray "neutral" or gray.

Here's another "aid". It gets more involved with gray shades and colour tones.

Another "aid", but this one is white. Again, a pure "white" tone will have equal amounts of the 3 main or "primary" colours, thus it remains "neutral". Measured in Photoshop, if imperfect, will register varying amounts of numbers. 

In the above image, I've "corrected" the numerical values to present the "correct" value of white.
In both the white and gray "aids" it's easier to measure the values than try to "see" them with your eye.

As you can see in the above 2 images, the white looks the same in both photos!






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