That dreaded CA
Some of you are thinking “why so down on California?”, but while I have my issues with California (I grew up there) what I mean by CA is Chromatic Aberration. For those who still may not know what this is I recommend you look it up, or better yet just follow this link to a great explanation -
https://photographylife.com/what-is-chr ... aberration. We can argue “‘til the cows come home” on whether or not CA has a negative effect on the usefulness of a riflescope, after all, we are not taking pictures through our scopes (well… actually I am, but only for this review), put plain a simple - CA bothers some people more than others (and if you haven’t noticed CA in your scope I’d recommend you not try to find it). Will CA cause you to miss a target? Doubtful, but it does have an effect on micro contrast as well as scotopic vision when the light gets low that could, in fact, degrade image quality (IQ), and let’s face it, when we are paying this much money ($3000+ for all these scopes) we are expecting to get the utmost in IQ. Because CA does bother me, especially in high end optics it is something I look for and evaluate. I did a review of the Kahles K624i Gen III when it was first introduced and I soon realized that scope performed very poorly when it came to CA, so much so that it affected the low light performance when I was comparing to other scopes with smaller objectives, and if there was any hint of snow on the ground (I live in Colorado) the annoying purple fringe was all over the place.
CA usually rears its ugly head the most with high contrast situations so having something white with a dark background will usually induce CA more than say green grass in front of brown dirt, but as previously mentioned CA can affect IQ even when you don’t “see it”. For those who still may be missing the concept here, take a look at the below image showing what CA looks like (Note: This is not from a scope within this test):
What is Chromatic Aberration?
Chromatic aberration, also known as "color fringing" or "purple fringing", is a common optical problem that occurs when a lens is either unable to bring