Celestron 71198 Cometron 7x50 Porro Prism Binoculars, Black

Product Information

The problem here is that the magnification of the image also magnifies any movement, so the higher the power, the harder it is to keep the view still.

Other important factors include ‘feel’, which combines the binoculars’ weight and size with balance, tactility and grip. To increase the exit pupil in the example above, we could, of course, increase the objective lens size.So as well as taking the weight off your arms, this is the other reason why you need a tripod when using high powered/giant binoculars for astronomy.

Efficient use of the light gathered is particularly important at high magnifications where images appear darker or for applications were colour identification is essential. A tripod adaptor bush means these binoculars can easily be mounted on any standard photo type tripod with an L Adaptor (sold separately). Excellent casual stargazing for the money These are a really great item, good value for money, easy to hold for extended viewing, decided on these instead of the 10x50s after advice from Harrisons. It is also a feature that many birders look for as it makes locating and then following fast moving birds at closer ranges much easier. I bought these to replace a similar pair I broke by standing on them whilst fighting with a wayward sheet.All pairs passed our ‘dunk’ test for floating (with swim strap where appropriate) and waterproofness. Only found on very high-end instruments, these eliminate many field aberrations that most leave uncorrected, with the result being much less distortion for a sharper, clearer images right to the edges of the view. They have no grip on the casing: all the testers commented on this, some regarding the binoculars as ‘slippery’. This allows for differences between a user’s individual eye focus by rotating the eyepiece, which is designated by + and –.

Prism Glass Glass – These use the cheaper BK-7 prism glass, whereas higher end binoculars will use better quality glass like BaK-4 that has a lower bubble count, fewer imperfections and thus generally delivers a higher quality image. We found this helped when we were trying to split the double star Albireo, which we could just about do but only with a tripod.of eye-relief is good and along with the improved twist-up eyecups makes them a solid choice for eyeglass wearers. When I first used them on my boat they acquired some salt spray, so I carefully rinsed them off in fresh water back at home. A linear vertical and horizontal scale visible in one lens which enables distances or heights to be determined, either by reading of a scale marked on the casing or by calculation. The high quality 7x50 specification with long eye relief eyepieces, XL prisms and anti-reflective lens coatings combine to maximise depth of focus, field of view, resolution and low light gathering. Binoculars can be adjusted for variations in the distance between different users’ pupils by rotating the lenses about a central hinge.

The Weems PRO 7x50 binoculars are loaded with features for discriminating professional sailors and mariners. The female testers praised their light weight and Oksana liked the soft eye shields, but both found the compass light button hard to press.Cometron 7x50’s wide field of view lets you explore expansive swaths of the sky to quickly pinpoint exactly the object you want to see, then keeps it in your sights without constant movement. We had an agonising wait for a clear night after they arrived, but now we all race up to the loft to look at the moon, M42 and the Pleiades every chance we get. Roof-prism binoculars have objective lenses approximately in line with the eyepiece and lead to a more compact design: they are however harder to shock proof and more expensive to produce than Porro prism binoculars. However, if you keep them at home, or safe and out of the rain and away from dust they will be fine. Very Good As a retired mariner where 7 x 50 binoculars were the best for horizon scanning and for keeping an eye on deck cargo, these Helios Fieldmasters are excellent and remind me very much of my years at sea in the Merchant Navy.