CN FORUMS ARCHIVE Telescope Reviews: Oberwerk 8x40 Mariner

Having owned an Oberwerk 8x40 Mariner for a few weeks now I thought I’d share my impressions. I ordered them from BigBinoculars.com and they took about 2 weeks to reach the UK after the usual processing time in UK Customs and the Post Office. The binoculars arrived very well packed and padded.

On opening the box I was quite amused by the retro-looking black vinyl case; very shiny black ‘leather look’. At least a functional case is provided.

The binoculars themselves are very squat with fat prism housings. They happen to fit my hands perfectly. For me this makes the view extremely steady. Looking through them for the first time I was a bit disappointed, but then I realised they were very slightly out of collimation (not surprising after a journey from China to the USA and then to England). A very small turn of one collimation screw (less than a quarter turn) transformed the view. The 8.2 degree field gives and apparent field of view of 66 degrees which is quite impressive. I had expected very obvious distortion and/or softening at the edges but was pleasantly surprised. The edges are soft but the view is so wide this only affects your peripheral vision so the overall impression is still very nice. What really surprised me was the performance in the central 25% of the field. Looking at craters along the terminator I had one of the sharpest views I’ve ever seen in an 8x binocular. The central performance left my old 8x and 7x binoculars for dead. I had to pull out the Nikon 10x42 SE to get a better view. However, it’s not all plain sailing. I find eye-positioning is quite fussy to get the sharpest view. Also, I was rather surprised and disappointed to find that these are NOT REALLY AN 8x40. What do I mean? I noticed very quickly that the exit pupil is nowhere near the 5mm it should be in an 8x40. After a few attempts at measuring it I’d say it’s closer to 4mm meaning that the binocular is operating as an 8x32. Looking into the objectives I can see a small baffle that looks as though it’s cutting down the aperture and is the most likely culprit. Having said that, they’re still extremely bright for there size. In fact they’re so bright I wonder if there’s some special glass in there somewhere. The other thing that makes me wonder about the glass is the colour rendition. In daylight the colour reproduction is superb and clearly beats some of my expensive birding glasses (which is rather vexing !) in a direct comparison when viewing waders up to 100m away. Whilst I was looking at the light-path I also noticed that internal construction is very clean and all optical surfaces seem to be multi-coated as stated. The coatings appear to be even and of good quality.

At first I found the focussing to be lumpy and stiff with plenty of delay when changing direction. After a couple of days I introduced a very tiny drop of WD-40 into the top of the focuser and kept on using the binoculars normally for another few days. This seemed to do the trick and now the focussing is much smoother with hardly any delay.

Despite these set-backs I’m still very impressed with my purchase. Resistance to flare is excellent, central definition is superb, eye relief is good enough for use with glasses on, they’re bright and built like a tank for very little money.

Edited by Dog Star (09/04/06 11:53 AM)