CA parameters
CDK said:
Today whilst at a friend house, saw a number of Red Kites in the sky, as I didn't have my bins I borrowed my friends new Leica 8x42 BN. Enjoyed watching the Kites, BUT, watching them in the sky did highlight the distinct yellowing around the bird. I have used Leica in the past and maybe did not see the CA, or did not want to see it, but today it was certainly there.
Visibility of CA depends on more than 1 factor. First the binocular itself. Here we have to assess every type for itself. So if let us say a 10x42 model shows CA that doesn´t mean the 8x42 of this brand works the same in this respect and vice versa. In the past Leica Trinovid 10x50 BN was the bino of all I´ve ever tested with the best performance in respect of CA. But 10x32 Trinovid BN and also the 10x42 Ultravid showed CA to me even in the centre of view in very high contrsty objects.
Second factor as mentioned here many times is the object to view. Examples of objects with a maximum of contrast providing an effective CA testing are:
power lines, the smaller branches of trees, aerials for tv on the houses - all these against the bright sky. If you are in a shop you can go outside and find easily one of these objects. I promise you: if the bino is working fine at these objects they will work also good in the field.
Watching raptors against the bright sky as you did is also a challenge in the field for almost every binocular.
If I´m doing these testing I can find CA with every bino and every scope available today.
The third factor frequently forgotten but also important are weather and light conditions. It´s not that easy that one can say in sunshine CA is better than in bad weather. My experiences are these: when humid air, high fog and bright light come together CA is most visible. (That´s why I buy binoculars only in November

)That means: looking at the same object the one day CA could be visible and at another it is not.
I can´t say how differences from person to person affect perception of CA. But they certainly exist.
Steve