MAXBRIGHT 2" Mirror Diagonal with Dialectric Coating and Brass Locking Ring (PMDMAX) скачать в хорошем качестве

MAXBRIGHT 2" Mirror Diagonal with Dialectric Coating and Brass Locking Ring (PMDMAX)

The Astro-Physics 2" MaxBright Diagonal was designed with several unique features to provide optimum performance and years of use. I used this diagonal to observe two challenging targets : Quasar 3C 273 and the lunar domes near Arago. Dielectric Coatings The Astro-Physics 2" diagonal has a very high-tech dielectric coating that was developed originally for military optics used in hostile environments such as blowing desert sand. There is no aluminum or other reflective metal used. The reflective surface consists of multiple layers of thin film oxides, similar to those used in anti-reflection coatings. The coatings are deposited using a sophisticated low-stress deposition method. Advantages of the Astro-Physics Dielectric Coatings Reflectivity - Reflectivity is above 99% over the entire 4000 to 7000 Å photo-visual range. Thin film coatings have extremely low surface scatter compared to aluminum or enhanced aluminum coatings. Dielectric coatings (if done right) will result in less scattered light. Examination with a laser source shows approximately a 5 fold reduction in surface scatter, a tremendous improvement over aluminum mirrors. Durability - The main advantage of a dielectric mirror coating (again, if done properly) is that the surface will be durable and will last for a lifetime. It will never tarnish and will be resistant to sleeks when cleaned. This means that for critical planetary viewing you can clean the surface and not have to worry about creating microscopic sleeks which lead to scattered light and lower contrast. For critical planetary viewing it is important to have the eyepiece and diagonal surfaces as clean as possible. You will find that even after one observing session the diagonal surface will accumulate crud. The inherently high contrast and cleanability of the Maxbright insures that it is never a limiting factor when viewing subtle planetary detail. For cleaning instructions, please use this link: Cleaning Instructions for the MaxBright Diagonal. The diagonal is accurately square to the optical axis due to the CNC machined parts and special mounting method of the mirror. The baffles and flat black interior allow maximum contrast. It is threaded for 48 mm filters so that you can change eyepieces with ease without changing the filter. Important: Consider the following dimensions to be sure that the barrel of your accessories will not strike the mirror. When using 2" accessories, the depth from the top of the diagonal to the mirror surface is 1.85" (46.99 mm). When using 1.25" accessories, the depth from the top of the diagonal to the mirror surface is 2.25" (57.15 mm); our 1.25" adapter adds another 0.25" (6.35 mm) height. Remember that if you add filters to your eyepiece barrels, the overall length changes. Specifications: The PMDMAX has a net spacing distance of 4.1" (104.1 mm), comprised of 2.75" (69.85 mm) from the center of the ocular opening to the mirror and 1.35" (34.29 mm) from the center of the objective opening to the mirror. The nosepiece net insertion depth is 1.4" (35.6 mm). As related by Roland Christen: "The elements are oversized and thick enough so that the end result is a highly accurate reflective surface over the clear aperture that is actually used with any kind of telescope. I personally assemble and test every diagonal under controlled conditions to assure that there is no detectable error of a perfect star image at very high powers. Measurements that I have made using interferometer techniques show that over the clear aperture of an F4.8 telescope, the flatness runs typically 1/40 wave, and I will guarantee at least 1/20 wave. This is not a flatness measure of the entire surface, just that part of the surface that is actually used to form an image of any particular star anywhere in the field of view. In the case of a star diagonal, what is most important is that the surface polish quality be very high (very deep polish with no remnant pits or subsurface damage to cause scatter), and very high quality low scatter coatings. These will insure highest image contrast with lowest scattering. Surface wavefront is also important, but the only effect of that is to introduce astigmatism into the image. A diagonal mirror cannot cause any other image defect. Astigmatism is very easy to detect, and I do test each and every mirror at very high power to insure that the star image seen through each Maxbright will be perfectly round. There is nothing more that you can expect from a star diagonal. The proprietary material we use is is low expansion, but not zero expansion type. It is not cheap common glass. It was chosen for its hard surface qualities and specifically to allow the manufacturer to achieve the excellent polish that we require. The material is being used in countless large diameter professional astronomical mirrors. It will not deform or produce unwanted image defects under any kind of temperature extremes. Roland Christen", Founder Of Astrophysics.