Source policy

We prefer official manufacturer specifications, recognised professional bodies, regulators and other primary sources for factual claims. Product pages record the exact model or part number and a dated availability check; retailer copy is not treated as independent proof of performance.

How we use evidence

We separate a published feature from the practical conclusion drawn from it. For example, a wider stated field can make a moving subject easier to find, but it does not prove that the image stays sharp at the edge. We show the inputs to our calculations and avoid treating stated specifications as guarantees of performance or individual fit.

Safety and legal claims use the relevant authority wherever possible. Solar-viewing guidance is sourced to astronomy bodies; wildlife-disturbance guidance is sourced to current UK government or conservation authorities.