Provides an upright, correctly orientated image for terrestrial observations. Suitable for use with Newtonian Reflector Telescopes or Refractor telescopes. Supplied with extension tube. (1.25"/31.7mm format) 

Battery operated red LED illuminates the crosshair reticle. 

These contrast-enhancing anodized aluminium, optical glass filters are designed to block out the wavelengths of light emitted by mercury-vapour light and other common causes of light pollution, whilst providing higher transmission at critical hydrogen-alpha and hydrogen-beta lines than competing filters. Bright, light-polluted skies appear much darker, and the contrast between object and sky is improved significantly. This contrast-enhancement effect is particularly apparent on nebulae. Unlike stars, emission nebulae give off light in a very narrow range of wavelengths. These filters allow maximum transmission of the important wavelengths of H-alpha, H-beta and doubly ionized oxygen – the ones most commonly emitted by nebulae. Views of galaxies and star clusters are also enhanced, but to a lesser degree. Also improves contrast on reddish planetary detail. Works well in telescopes of all apertures but is highly recommended for use on smaller telescopes up to 114mm diameter, where conventional filters swallow up too much light. Available in two sizes, threaded to fit either standard 1.25” or 2” astronomical eyepieces. Supplied with storage case.

The narrowband UHC filter, like the O-III filter, isolates the two doubly ionized oxygen lines (496 and 501nm) in addition to the hydrogen-beta line (486nm) emitted by planetary and most emission nebulae. This filter permits superb views of objects like the Orion, Lagoon, Swan and other extended nebulae. It performs well in smaller aperture instruments owing to its greater light transmission than the O-III, yet still suppresses light pollution well. The UHC filter is the best all-around dark-sky nebula filter. Available in two sizes, threaded to fit either standard 1.25” or 2” astronomical eyepieces. Supplied with storage case.

These high quality anodized aluminium, optical glass variable polarising filters reduce the amount of light entering your eyepiece. You can progressively dim the view when observing a bright object, such as the Moon or certain planets, to a level according to your needs, whilst increasing contrast, reducing glare and increasing the amount of detail that can be studied. The light transmission can be varied from 40% down to as little as 1%. The filter will not change the colour of the object being viewed and will prevent eye fatigue and loss of night vision. Each filter set consists of two polarizing filters, one which can be rotated in its cell to adjust the brightness. The filters, used as single elements, can also be used for daytime terrestrial use for reducing sunlight glare from lakes oceans or window glass. Available in two sizes, threaded to fit either standard 1.25” or 2” astronomical eyepieces. Supplied with storage case. 

The O-III narrowband filter is specially designed for the observation of gas and  planetary nebulae.

It distinguishes different contrasts of the wavelengths of light that pass through, giving ideal conditions for the observation of faint super nova remnants and planetary remnants.

The O-III narrow band-pass filter isolates just the two doubly ionized oxygen lines (496 and 501nm) emitted by diffuse, planetary and extremely faint nebulae. O-III filters work ideally with larger aperture telescopes in the 200mm and  larger range. With larger aperture telescopes, observers will have a better opportunity to identify nebulae objects in the deep sky. It can produce near-photographic views of the Veil, Ring, Dumbbell, Orion, plus many other nebulae under dark skies. These Available in two sizes, threaded to fit either standard 1.25” or 2” astronomical eyepieces. Supplied with storage case.  

Superb quality, non-focal reducing Field Flattener optimised for DSLR imaging on refractor telescopes with focal ratios of between f/5.5 to f6.0. Will also provide much improved results on refractors with focal lengths narrowly outside this optimised f/range. Integral T-Ring adaptor thread. High quality CNC machined body with gloss black anodised finish.