FIRST LIGHT
Altair Wave Series 130EDT-F F7 apo refractor
A winning performance for observing and imaging, on a par with pricier scopes
VITAL STATS
• Price £2,499
• Optics Air-spaced triplet
• Aperture 130mm
• Focal length 905mm, f/7
• Focuser 92mm rack and pinion with 1:10 gearing
• Extras Aluminium storage case
• Weight 12kg with rings and Losmandy bar
• Supplier Altair Astro
• Tel 01263 731505
• www. altairastro.com
The Altair Wave Series 130EDT-F has been updated for 2022, with upgrades that will be popular with both observers and astrophotographers. Large refractors like this 130mm triplet always have a special air about them, they look like a proper telescope, as it were, and the 130EDT-F is certainly impressive, while the quality and build are exceptional. The tube rings, for example, come complete with carrying handle and are finished in red anodising. They are meticulously machined with bevelled edges and give an indication of the attention to detail that has been lavished on the fit and finish of this telescope.
Another upgrade is to the dovetail bar, which now has a Losmandy-style profile. We found this helped with balancing the 130EDT-F, something which can prove a little tricky with large refractors. Weight-wise, the package tips the scales at around 12kg, which is perhaps on the hefty side, but reassuring that the materials used are solid and robust enough to provide years of enjoyment when investing in this telescope.
With a focal length of 905mm (f/7) the 130EDT-F hits the sweet spot for observing and photography alike. Additional options are available to enhance the photographic ability of the telescope, including a dedicated flattener. We were loaned a matching 0.8x PlanoStar reducer lens, which took the focal ratio down to f/5.6.
Looking sharp
With a brief window of clear skies available, our first light from the telescope came from a CCD camera without the reducer, the target being the Hercules globular cluster, M13. These initial images demonstrated that the triplet lens was producing sharp, distinct stars and the surrounding star field was free from any optical issues. Suitably impressed, we turned the scope towards the supernova which had appeared in NGC 4647, and almost without effort the large optics revealed not only the exploded star itself, but dozens of smaller, far fainter distant galaxies. Considering the images were taken in suburban skies in late spring without astronomical darkness, they provide convincing evidence for the good, contrasty views from the 130EDT-F, no doubt helped by the lens coatings and internal baffles.
Air-spaced triplet lens
Altair Astro provides an optical guarantee with the Wave Series refractors – each unit has a minimum performance level. Each telescope comes with a printed optical report relating to the serial number on the lens. Our review model boasted an impressive 0.972 Strehl reading, which is a measurement of optical quality, with 0.95 being the baseline for the Wave Series.
The proof of the pudding is in the eating, though, and our results both with a camera and an eyepiece do bear those figures out. Taking an edge-of-field star, captured by our one-shot colour CCD camera, we split the channels into red, green, and blue, blew the image up to 25x and compared the star sizes. There was negligible observable difference between the star sizes, demonstrating that the triplet lens, having been carefully aligned, performs its job of bringing all three colours into a single point of focus. This optical performance makes the 130EDT-F a desirable telescope for use with increasingly popular and capable one-shot colour astronomy cameras, and certainly with an eyepiece.
With an Atik 460EX camera, in 10’ exposures the 130EDT-F delivered distinct and sharp stars in M13 (4h 40’ total) 
Picking out the Sombrero Galaxy, M104, with the same setup using 1h 20’ of 10’ exposures
Eyepiece excellence
As the Moon became dominant, we switched to visual use of the telescope, using our own diagonal and eyepieces. Our 13mm, 100° eyepiece gave 70x magnification, and on the Moon, illuminated about 50 per cent or so; high in the sky, the results were breathtaking: the Moon almost appeared to be in 3D. Triplet telescopes are perhaps a luxury for observational use, but presented with views like these, that luxury seems perfectly justified. Switching to our 4.5mm eyepiece ramped up the magnification to 200x, which was pushing the seeing, but glimpses through steadier patches revealed craterlets within craters and definition inside illuminated crater walls, all without distracting colour artefacts on bright edges.
Our favourite view came from our 10mm eyepiece though, at 90x, with sharp views of craters, ridges and flows within the lunar maria. The skies weren’t really dark enough for deep sky objects, but M13 was visible with reasonable contrast and good distinction between stars, and we even got both galaxy cores from M51, thanks to the telescope’s 130mm lens.
Our observing notes included this sentence: “This is the kind of telescope that could tempt an astrophotographer to leave the camera and fit an eyepiece instead, offering lovely crisp views that are comfortable to observe.” We did go back to the camera though, this time with the 0.8x reducer in place, which screws firmly to the focuser. Again we were very impressed with the images and the 130EDT-F proved itself very capable on galaxies and the Iris Nebula. In particular, the updated focuser was a joy to use. Not only is it slick and responsive to work with, but locking the position was accurate without pushing the image off. The whole focuser can be rotated, or just the camera, with easy-to-use fittings.
In short, the 130EDT-F is an all-round, high-quality large refractor, providing excellent views and images comparable to more expensive telescopes.
KIT TO ADD
1. Altair Astro PlanoStar M92 1.0x reducer
2. Altair Astro PlanoStar M92 0.8x reducer
3. Altair Astro 60mm guide scope, Vixen bar rings and GPCAM2 guide camera combo
