TMB 4 mm Planetary II is a short-range eyepiece offered by TMB Optical, a company created by the renowned apochromatic refractor designer, Tomasz Back.
The 4 mm TMB Planetary II eyepiece is designed to achieve maximum contrast, detail and resolution when observing bright objects such as the Moon and planets, both on the optical axis and at the edges of the field of view. This eyepiece is characterized by a high transmission of light and minimal reflections. This allows you to achieve very high magnification with high quality mapping of objects in the reflex focuses , reflectors and catadioptical systems with good viewing conditions at the astonishing low price of the eyepiece.
A eyepiece designed for high magnification in virtually all telescopes. For example, for a 6 "f / 5 refractor (eg Bresser R-152/760), we get a 190x magnification, typical planetary (ideal for observing the structure of Saturn's rings, including Cassini's gaps and Encke's gap.) In a SCT 8" telescope f / 10 (eg Meade LX90 ACF 8 ") magnification will be 507x, used to separate very tight double star systems under ideal observation conditions.
Removal of eye relief of 10 mm is a very good result for an eyepiece with such a short focal length. Vignetting occurs only in people who need to wear optical glasses during observations and it is small. Also, this is not a major disadvantage, because the TMB Planetary II series glasses are dedicated to observing planets, double stars, etc. objects that are compact and stay in the middle of the field of view, where the human eye has the maximum sharpness of the image.
For telescope owners on Dobson assembly and other telescopes without drives, very small color fission and low level of other aberrations allows observation of planets drifting through the whole field of view (own 58 ° field) of the eyepiece, thus maximizing the observation time of the object between further telescope shifts.
Although the eyepiece is optimized for observing the subtle details of the Moon and planets, the eyepiece characteristics allow equally efficient use of the eyepiece for separating compact double systems or observing globular clusters.
| • Focal length: || 4 mm |
| • Field of view: || 58 ° |
| • Distance of the exit pupil: || 10 mm |
| • Diameter of binding: || 1.25 inches |
| • Anti-reflective layers: || FMC |
| • 6-element eyepiece |
| • Weight: || 142 g |
Logo variability: depending on the delivery from the factory, the eyepiece is either without a logotype or with the StarGuider logo