Wow! that is a great article to have. Thanks Wayne!!
My son, who has a moderate interest in astronomy, having job and family to keep him busy most of the time, got an inexpensive binocular to just do some quick scanning. Fortunately, his sky is darker than mine is even though he lives close by.
He said he thought something was wrong and asked me to to take a look. During the day, I could see something was amiss but I could see a merged image at times. I had a suspicion my eyes/brain were doing the aligning.
Ironically, when the right side was not in focus before adjusting the eyepiece to match, the alignment did seem off, as would be expected with the blur test. Only when in focus was I able to merge the images.
I just went out to do try the blur test on Sirius tonight, but didn't even have to. There were two distinct Sirius's a good distance apart, and though I could bring them closer, I couldn't come close to merging them. So the collimation is way off. Since they are new and just purchased we'll return them.
I guess looking at a bright star is more telling than an extended object with everything focused and your eyes right up to the eyepiece. But the daytime test would no doubt reveal the same condition, backing off a few inches.
I've heard this is a problem with many of the inexpensive import line binos.
Anyway, thanks all for the great info. If he decides to go with another bino, we'll know what to look for!!
Edited by Joe1950, 17 January 2018 - 10:04 PM.