Night shot @ Robinson Rd

[Wolfgang]

I think the noise is quite bad and so is the CA. No offence

[Wolfgang]

Quote: Originally posted by Punkie I think the noise is quite bad and so is the CA. No offence

None taken. No worries.

Thanks for the comment.

[chkoch]

Just wondering...what does CA stand for?

[Yongliang]

CA = chromatic aberration.
It means purple fringing of objects shot under strong lighting.
Correct me if I'm wrong, cos I'm also a newbie...=)

[revenant]

Quote: Originally posted by Yongliang CA = chromatic aberration. It means purple fringing of objects shot under strong lighting. Correct me if I'm wrong, cos I'm also a newbie...=)

yeah. Here's how to repair images with CA.

Anyway, how about lying in the grass patch at the middle of the 4 buildings and shoot upwards? Was taking a break at Robinson after my flyers distribution, looks up and saw 4 tall buildings and was thinking of shooting it but here came the big problem..... I AIN'T HAVE A DIGICAM YET!!!

Shoot in a daylight, with 4 buildings appearing from each corner

[ziploc]

Quote: Originally posted by Yongliang CA = chromatic aberration. It means purple fringing of objects shot under strong lighting. Correct me if I'm wrong, cos I'm also a newbie...=)

Some CA's are blue color

[chkoch]

Hi,
Just wondering whether CA occurs only in digital cameras or does it occur in film cameras too? Was reading that day something about APO lens and what they are for....seems to me that APO lens are supposed to correct CA too. Is that right?

Kok Chew

Quote: Originally posted by chkoch Hi, Just wondering whether CA occurs only in digital cameras or does it occur in film cameras too? Was reading that day something about APO lens and what they are for....seems to me that APO lens are supposed to correct CA too. Is that right?

My understanding is that CA is a characteristic of the lens, thus it is definitely a potential problem regardless of the recording medium. However, digital cameras tend to accentuate CA because of CCD blooming.

[chkoch]

Huh? What's CCD blooming? I understand that the CCD records images in three colours separately for each shot that you take. Does it have anything to do with that?

Quote: Originally posted by chkoch Huh? What's CCD blooming? I understand that the CCD records images in three colours separately for each shot that you take. Does it have anything to do with that?

The CCD (or CMOS for some cameras) is essentially a grid of individual light sensors, each of which gains an electric charge when light photons fall on it due to the photoelectric effect.

However, there is a limit to how much charge each sensor can hold; as such, when the amount of light falling on the sensor is very high, the excess electric charge "overflows" and some of it spills over to neighbouring sensors, thus increasing the reading on these neighbours. This phenomenon is called blooming. The exact design of the CCD/CMOS grid will determine how the extent to which this occurs in practice.

DPReview has a nice sample photo of blooming in action at http://www.dpreview.com/learn/Glossa...looming_01.htm

[traveler]

i always thought CA is most evident in non-APO telephoto lenses?