Astronomical telescope Boren-Simon N 150/420 6″ PowerNewton astrograph OTA
Have you ever dreamed of gathering enough data for a final, detailed image of a distant galaxy or nebula in just a single clear night? With the Boren-Simon PowerNewton 6″ N 150/420, that dream becomes reality. Thanks to an extremely fast focal ratio of f/2.8 (effective focal length 420 mm with the reducer/corrector), you can reduce exposure times to a fraction of what slower systems require - while still maintaining excellent sharpness across the entire image field.
Why f/2.8 changes everything
Light gathering ability increases with the square of the f-number, so moving from f/6 to f/3 means exposures that are four times shorter. In practice, this delivers several key advantages:
- No cooled astro camera required - the astrograph works great with a standard DSLR or mirrorless camera (MILC) without cooling
- Easier to overcome light pollution when using narrowband filters
- In a single night you can accumulate as much raw data as would otherwise take a week of waiting for clear skies
This is a huge benefit especially for observers in regions where clear nights are not a given.
Professional 4-element ED NEXUS corrector
The key to maintaining image quality at such a low f-number is the professional 4-element ED NEXUS reducer/corrector, which provides full coma and aberration correction up to APS-C format. Stars are pinpoints across the entire frame - no wings, no coma spikes at the edges of your images. The corrector has a working distance of 55 mm from the M48 thread, making adaptation of standard astro cameras and DSLRs straightforward and hassle-free.
Carbon tube - light, rigid, ready to travel
The tube is made from carbon fibre, offering exceptional rigidity at low weight. Key dimensions and specifications:
| Parameter |
Value |
| Aperture |
150 mm (6″) |
| Focal length (with corrector) |
420 mm |
| Focal ratio |
f/2.8 |
| Tube length |
540 mm (without cap, with collimation screws) |
| Tube diameter |
176 mm |
| Total weight |
under 4 kg |
| Primary mirror reflectivity |
94 % |
| Secondary mirror reflectivity |
94 % |
| Secondary mirror minor axis |
70 mm |
The compact dimensions and low weight mean that even lighter travel mounts can carry this astrograph comfortably - no need to invest in a heavy and expensive mount.
Dual-speed focuser with motorisation support
The TS UNCN2-G2 focuser is a dual-speed unit (1:10 ratio) with a 2″ drawtube, designed to carry both DSLRs and heavier astro cameras without any tilt. The focuser is compatible with motorised autofocus drives such as the ZWO EAF - ideal for observatory use or remote operation. The thread connection is T2, so adapting standard astrophotography accessories is straightforward.
Two focal ratios in one instrument
One of the most interesting features of this astrograph is the ability to quickly switch between two focal ratios:
- f/2.8 - 420 mm - with the NEXUS ED corrector, for maximum speed and wide-field deep sky imaging
- f/4 - 600 mm - by swapping to the optional aplanatic coma corrector TSGPU, optimised for f/4 systems, you gain a higher resolution setup suited to planetary nebulae, globular clusters or small galaxies
Switching between configurations takes just a few minutes and collimation remains completely undisturbed. For correct placement of the GPU corrector, we recommend using the 2zKonter spacer ring, which ensures the optimal position without the need for extension tubes.
The right choice for serious astrophotographers
The Boren-Simon PowerNewton 6″ N 150/420 is the choice for astrophotographers who want to make the most of every clear night - whether shooting from a dark rural site or battling light pollution in the suburbs. The combination of extreme light gathering power, a professional ED corrector, a rigid carbon tube and the flexibility of two focal ratios makes this one of the most versatile astrographs in its class. If you are looking for an instrument that lets you go straight to results without unnecessary waiting or compromises in image quality, this is it.
