下面是BirdForum上面关于regal m2 100 vs Nikon ED82的对比（仅光学设计方面）。懒得翻译了自己看。
The Celestron has so many design disadvantages that I have particularly low expectations for it. Firstly, it uses a simple doublet objective with a very low focal ratio, a bad combination. It’s very unlikely that a mass-produced f/5.4 100mm objective will be well corrected. A very cheap one, like this, is likely to have defects piled on top of its inherent aberrations. In contrast the Nikon uses an f/6.4 triplet, a more promising design, which has shown itself to be capable of excellent corrections in real world testing. The Celestron also uses the cheapest and least efficient erecting system (Porro followed by semi-pentaprism). The old Nikon Fieldscopes used the best and most efficient erecting system of any angled scope (an oversized Schmidt prism). The Celestron uses a moving prism for focusing. I’ve yet to see any scope of this design that didn’t suffer considerable aperture reduction at close distances. Because this scope shares the same prisms with the smaller, slower Regals I suspect its loss of aperture is quite large. I doubt that it has a full 100mm aperture at any distance. Nikon uses a moving doublet lens group for focusing. That system doesn’t restrict clear aperture at any distance when it’s properly sized.
I consider all scope specimens of any design or brand to be guilty until proved innocent, but the Celestron Regal (particularly the 100mm version) is one of those products that promises too much for too little. I’m inclined to hang it first, then hold a trial.
| 
IP卡
狗仔卡
提升卡
置顶卡
沉默卡
喧嚣卡
显身卡
