This weekend I had a chance to compare my 10x42 Legend Ultras to my friends, the ones I originally borrowed which helped me decide which ones to get. His were very bright and clear compared to other brands to I ordered a pair. While mine still appear bright and clear, when i compared them directly to his in low light (last 10 minutes before dark), his were definately brighter. Not hugely, but distinctly. This was disappointing to me, i would have expected them to be virtually identical since they are both relatively new and both 10x42. Not sure why they would be different or how...had my wife look w/o telling her why i was asking and she immediately noticed the same thing.
A bit of wild speculation.
I've tried out a lot of pairs of reasonably priced bins over the last year including some models several times. I've noticed quite a bit of variability in the samples from obviously faulty to more subtle differences in resolution, contrast and edge distortion for example. It is quite possible that you have just noticed differences in the 'normal' spectrum for that model.
One thing I noted about the Legend Ultra HD is that it appeared 'bright' in the same way that the Hawke Frontier ED and one or two others do. I'm somewhat guessing here, but I think these pairs may have a relatively high blue and low red transmission compared to other designs. It might be that you have detected a, possibly small, difference difference in the balance of the transmission spectrum rather than overall light intensity issue.
I personally prefer the pairs with more red in the spectrum as they seem to have more contrast to my eyes, even though they may not seem as 'bright'. I know many would disagree. You might try comparing the look of the anti-reflective coatings of the two pairs to see if you can detect any differences.
David
There is considerable sample variation , perhaps around 10%, even within the alpha glasses, still more among the rest.
Experts on this forum such as Henry Link or Surveyor have commented on this topic in some detail on earlier threads.
That is why people speak of "cherry specimens".