Apollo 150
|
Helios Apollo 150. 6" f/6.7 Newtonian with spherical aberration correction lens/focal extender. Tube assembly on Helios EQ3 equatorial mount and tripod. Accessories included - 20mm, 10mm Plossls, 2X Barlow lens, Pole-finding scope, 6X30 finder and bracket.Price - only £319 while stocks last |
Explorer 150 |
Helios Explorer 150 Price - £389
|
||||||||||||||||||||||||||
|
An excellent value 6" f/5 classic Newtonian for the beginner or as a second, easily transportable telescope. The Explorer 150 features a paraboloid primary, 1 1/4" Rack and Pinion focusser and has reduced thickness spider secondary support arms, from the original 2mm to the new 0.5mm (original 2mm support arms shown in above photograph). This reduces the total area of obstruction in front of the primary, slightly increasing planetary contrast. The Helios EQ3 German equatorial mount can be driven by the addition of the optional Helios motor drives to either RA or both RA and Dec. axis. Manual slow motion controls to both RA and Dec. axis provided. The best value for money 6" Newtonian on the market? |
|||||||||||||||||||||||||||
Explorer 200 |
Helios Explorer 200 Price - £489
|
||||||||||||||||||||||||||
|
Arguably the best value for money beginners telescope on the market. The 200mm paraboloid primary mirror is capable of good resolution on lunar/planetary images, plus the important 8" light grasp that enables clear, resolved views of globular clusters and other deep sky images (Tested unit revealed the Veil nebula in Cygnus without an O III filter). The thickness of the spider secondary support arms are now reduced to 0.5mm from the original 2mm (0.5mm arms shown in right photograph above). This allows a slight increase in low level planetary contrast. The Explorer 200 is offered on the Helios EQ5 German equatorial mount, a more substantial version of the EQ3. The entire telescope package is easily transportable. The mount can be driven by the addition of the optional Dual axis or single axis Helios motor drives plus hand controller. Dual axis manual slow motion controls are provided. A 2" Rack and Pinion focusser is included with an 1 1/4" adapter plus a useful 9X50 finderscope. Full frame 35mm photography possible through the telescope as well as the piggy-back camera platform on the tube rings. My personal favourite Helios telescope. |
|||||||||||||||||||||||||||
Evostar 102 |
Helios Evostar 102 Achromatic f/9.8 Refractor
|
||||||||||||||||||||||||||
|
Standard Specification: |
|
|---|---|
|
Magnification Range |
50X, 100X |
|
Objective Lens Diameter |
102mm |
|
Diffraction Limited Optics |
|
|
Telescope Focal Length |
1000mm (f/9.8) |
|
Eyepieces Supplied |
10mm, 20mm Plossls |
|
2X Deluxe Barlow lens |
|
|
6x30 Finder Scope |
|
|
Dual Fit 1.25"/2" Focusser |
|
|
Direct SLR Camera Connection possible |
|
|
Aluminum Tripod with Accessory Tray |
|
|
Fully Multi-Coated Optics |
|
|
Evostar 102-1 supplied with EQ3-2 Deluxe Equatorial Mount with built-in polar alignment scope |
|
A better quality 4" achromatic refractor at an affordable price. Quite capable of 50X per inch of aperture, this instrument will provide great views of lunar/planetary detail as well as deep sky images within reach of a 4" aperture. Tube assembly is mounted on the Helios EQ3 German equatorial, with slow motion manual controls to both axis, and the option for adding dual or single axis motor drives. We offer the facility to notably increase the performance of this telescope by the addition of the Aries Chromacor I or the superior new Chromacor II (Please refer to notes on the Chromacors at the bottom of the page)
Evostar 120 |
Helios Evostar 120 Achromatic f/8.3 Refractor
|
||||||||||||||||||||||||||||
|
Standard Specification: |
|
|---|---|
|
Magnification Range |
50X, 100X |
|
Objective Lens Diameter |
120mm |
|
Diffraction Limited Optics |
|
|
Telescope Focal Length |
1000mm (f/8.33) |
|
Eyepieces Supplied |
10mm, 20mm Plossls |
|
2X Deluxe Barlow lens |
|
|
Built in polar alignment scope |
|
|
6x30 Finder Scope |
|
|
Dual Fit 1.25"/2" Focusser |
|
|
EQ3-2 Deluxe Equatorial Mount |
|
|
Direct SLR Camera Connection possible |
|
|
Aluminum Tripod with Accessory Tray |
|
|
Fully Multi-Coated Optics |
|
120mm aperture refractor providing increased light grasp over the Evostar 102 for brighter deep sky images. Great views of lunar/planetary detail. Capable of 50X per inch of aperture. Tube assembly is mounted on the Helios EQ3 German equatorial, with manual slow motion controls to both axis. The mount can be driven by the addition of the optional single axis or dual axis Helios motor drives. Tube assembly is also offered on the more substantial EQ5 mount for an additional £50. We offer the facility to notably increase the performance of this telescope by the addition of the Aries Chromacorr I or the superior new Chromacor II. (Please refer to notes on the Chromacors at the bottom of the page)
Evostar 150 |
Helios Evostar 150 Achromatic f/8 Refractor
|
||||||||||||||||||||||||||||
|
Standard Specification: |
|
|---|---|
|
Magnification Range |
48X, 120X |
|
Objective Lens Diameter |
150mm |
|
Diffraction Limited Optics |
|
|
Telescope Focal Length |
1200mm (f/8) |
|
Eyepieces Supplied |
10mm, 20mm Plossls |
|
2X Deluxe Barlow lens |
|
|
Built in polar alignment scope |
|
|
9x50 Finder Scope |
|
|
Dual Fit 1.25"/2" Focusser |
|
|
EQ-5 Deluxe Equatorial Mount |
|
|
Direct SLR Camera Connection possible |
|
|
Aluminum Tripod with Accessory Tray |
|
|
Fully Multi-Coated Optics |
|
The largest of the Evostar refractors and the most impressive. A mounted 6" refractor for under £1000, even 10 years ago this was unthinkable. Excellent deep sky, lunar and planetary images, outperforming 8" f/10 SCT's for low level planetary contrast. Capable of 50X per inch of aperture with favourable seeing conditions. Tube assembly is mounted on the Helios EQ5 with manual slow motion controls to both axis and the facility to add the optional single axis or dual axis Helios motor drives. A useful 9X50 finderscope is included. We offer the facility to notably increase the performance of this telescope by the addition of the Aries Chromacor I or the superior new Chromacor II (Please refer to notes on the Chromacors at the bottom of the page)
Startravel 80 Tube Assembly
Helios Startravel 80 Achromatic f/5
|
Aries Chromacorr I |
The Aries Chromacorr series are chromatic aberration correcting lens systems, designed around (initially) the Chinese Synta f/8 - f/10 achromatic refractors. Although some report success with other brand refractors of similar focal ratios (f/), because of the popularity of Synta refractors (branded under Helios Evostar, Celestron CR 102 and 150 HD, Bresser, Skywatcher et. al.) the Chromacorrs were designed to correct chromatic and spherical aberration inherent in the objective lens doublets of these mass produced Chinese refractors. An in-depth explanation of the Chromacor principle can be found at http://www.apm-us.com/amateur/chromacorr_tech.htm |
|
Synta f/8 - f/10 refractor objectives are often found to contain moderate to notable undercorrection for lower order spherical aberration of between 1/7th to 1/4 wave although an increasing number are now being tested as neutral, with very few overcorrected. In order to correct this aberration, Chromacorrs are designed to be undercorrected, overcorrected or neutral, in order to counter the level of spherical aberration in a particular objective lens.
So, lower order spherical aberration can be eliminated and chromatic aberration drastically reduced by the use of a Chromacorr I in Synta 102mm f/10, 120mm f/8.3 and 150mm f/8 refractors. The longer the focal ratio, the greater correction of chromatic aberration is noted. The 102mm f/10 displays virtually no chromatic aberration at all with Chromacorr I, whilst the 150mm f/8 performs to the standard of a semi-apochromat. |
|
|
|
|
 |
|
|
If the level of spherical aberration is known by the owner, the appropriate Chromacorr can be ordered. If not, Bray Imaging can match a Chromacorr to a specific refractor providing the tube assembly is in our possession for testing. * Please note, all Chromacorrs require the use of a 2" Star diagonal. The Chromacorr screws into the barrel of the diagonal which is then inserted into the focus mount. Bray Imaging can supply the following 2" diagonals - Synta (Helios) 2" diagonal - £89
|
|
Aries Chromacorr II |
|
Just released by Aries, early tests show at least 30% correction improvement over Chromacorr I. The 6" f/8 Synta is (with Chromacorr II) now a near-apochromat, the 120mm f/8.3 the same, and the 102mm f/10 fully apochromatic. Please watch this page for future photographic evidence. |
