| Why are eyes red in photos? | | | | this feature can have a side-effect that results in |
| Red-eye is a phenomenon that happens only | | | | photos having people's eyes closed. The reason is |
| when taking photos using a flash. When taking | | | | that the pre-flash strobes blind the people and |
| photos in day light or when in high ambient light | | | | cause them to close their eyes. |
| scenarios people's eyes look normal. When taking | | | | Other ways to prevent red-eye |
| pictures in low ambient light scenarios using a flash | | | | Understanding what causes red-eye helps being |
| the result many times is redness in the people's | | | | more creative in preventing it. Following are some |
| eyes. | | | | ways to prevent red-eye other than using the |
| The reason for the color red is simple - when | | | | built-in camera red-eye reduction feature: |
| flash light from the camera hits the eyes it | | | | Increasing the light where photos are taken (for |
| penetrates and is reflected back from the retina. | | | | example by turning on the lights in a room before |
| The color of the reflected light is red because the | | | | taking photos of people) causes people's pupils to |
| light is actually reflected from the red blood in the | | | | reduce in size and eye redness to reduce. |
| retina. | | | | Point the flash away from the eyes. Since |
| In some scenarios the red-eye is evident while in | | | | red-eye is caused by flash light reflected from the |
| others it is mild or doesn't seem to appear at all. | | | | retina the best way to prevent red-eye would be |
| One of the main factors for that is the state of | | | | to eliminate such reflection as much as possible. In |
| the pupils. If the pupils are dilated (for example | | | | most cameras the angle between the flash and |
| the pupils dilate in darkness or when drinking | | | | the lenses is narrow (this is especially true for |
| alcohol) more light is reflected back from the | | | | built-in flash and pocket cameras) causing most of |
| retina and the eyes in the photo appear redder. | | | | the flash to bounce back from the retina to the |
| Common way to reduce red-eye | | | | lenses. Increasing the angle (for example by using |
| The most commonly used method to reduce | | | | an external flash) reduces the reflected light. You |
| red-eye is activating the camera's built-in red-eye | | | | can also use a bounce flash - by having the flash |
| reduction feature. The red-eye reduction feature | | | | light bounce off a bright surface (a white wall or a |
| is very simple yet effective. When turned on the | | | | professional reflector) most of the direct |
| camera shoots a series of pre-flash strobes | | | | reflection from the retina can be eliminated. |
| followed by one more strobe when actually taking | | | | Red-eye can also be removed after photos were |
| the photo. The pre-flash strobes cause the pupils | | | | already taken by using photo processing software |
| to reduce in size and by the time the photo is | | | | on your PC. Most digital cameras include a CD with |
| taken the pupils are small enough for the eye | | | | PC software that embeds this feature. Although |
| redness to substantially reduce. | | | | this method doesn't eliminate the red-eye from |
| The red-eye reduction feature does what it is | | | | the source it can result in a practically red-eye |
| supposed to do: reduce the red-eye effect but | | | | free photo. Some software are better than |
| almost never is it completely prevented. There | | | | others some are manual while others |
| are many limitations to this feature for example | | | | automatically identify the red-eyes and process |
| pupils reaction time to light can vary. In addition | | | | that area to revert to normal eye colors. |