I recently acquired a set of Zeiss Terra ED 8x42 binoculars, and thought I should provide my impressions. To interpret these impressions you should have a bit of background, especially the following points:
I am not an expert in binoculars. Any knowledge of optics I might have comes from photography and there are considerable differences in application between the two.
These binoculars are by far the best I have ever looked through. I have no points of comparison with better binoculars, only those not as good in one way or the other.
The things I like about these Terra ED 8x42 binoculars:
Good contrast and saturation, a punchy image giving the impression of great clarity, especially as regards colour saturation. (The close-up view of a Rainbow Lorikeet with these binoculars is quite a treat!)
Good resolution on centre extending to about 75%-80% of the radius of the field of view. The drop-off from there is fairly rapid but not dreadful and not distracting.
Chromatic aberration is well controlled. It is not often noticeable in the centre 75%-80% of radius, becoming apparent thereafter (especially with bright sunshine on distant foliage).
Excellent flare control. While these binoculars can be made to flare, it takes work in challenging conditions and the area blocked out by flare is generally small. Veiling flare is particularly well-controlled, even under challenging conditions, with image contrast mostly preserved in conditions where I would have expected otherwise.
Close focus to around 1.5 meters. I like being able to focus that closely and I use the facility frequently for birds feeding on the native bushes near my balcony. Its nice not to have to back up to get the birds in focus.
Good apparent depth of field (width front-to-back of the in-focus area) and a nice 3D effect (I had expected a more substantial difference between these and the porro-prism designs Im more familiar with).
Solid-seeming construction, giving an impression of ruggedness (I guess only time will tell how justified this impression is). The focus wheel turns smoothly, with no play, while the dioptre and eyecup adjustments are smooth, positive, and appear to stay in place without further fuss through repeated usage. The hinge for adjusting eyepiece spacing seems solid, with firm-but-smooth resistance and no tendency to change without intentional alteration.
The supplied accessories including neck strap, rain guard, objective protection and cleaning cloth appear to be functional and of good quality. It did take me a while to figure out the objective cover, but I find it useful enough once worked out (a line or two in the instruction manual might have been a good idea).
Things to note (not necessarily positive or negative):
Eye relief is good for me, and the eyecups comfortable, both with and without glasses (I generally wear glasses). This, of course, may vary for others.
I find the size and weight about perfect, allowing a comfortable, steady, hand position with easy focus adjustment via two fingers on the focus wheel. Others may find them less comfortable, especially those with larger hands. I would find them a deal less comfortable if the barrels were shorter or narrower suggesting those with larger hands may find less comfort than I have. (Note: Id guess my hand-size is around the male average.)
The gearing on the focus adjustment is quite rapid, with only small movements making fairly large (but, I find, quite precise) focus changes. I like this (quite a lot, in fact) but others may prefer lower gearing.
Direction of the focus wheel is clockwise to infinity, anti-clockwise to focus closer. I have no preference; others might.
Things which could use improvement:
Chromatic aberration in the outer zones. While CA is generally well controlled, I find it occasionally appears strongly (distractingly so at times) in my peripheral vision. This might be making a vice from a virtue: the colour saturation is so good that it makes CA stand out more! Ive (mostly) learned not to be distracted by colour flashes in the corner of my eye (of course, this may have me ignore something I should notice).
Field of view: it is not exceptionally wide, and a wider field of view is always desirable, as long as other important attributes (like price!) are not sacrificed.
Lack of a carry-case, requiring one to be obtained separately (assuming you want one; I did). Yes, I know about the stupid display case (and even understand why Zeiss did that). But, still, there has to better way. I even have suggestions, but I doubt anyone will be clamouring to hear them.
I have been very pleased with my Terra EDs in use so far. I've used them mostly for birdwatching - whether from my front balcony or walking through local bushland, often near dawn or dusk. Are there better binoculars out there? I am sure there are, though I haven't looked through them. I am also sure, though, that these Terra EDs provide a combination of price, specification and view that suits me very well indeed.
