Takahashi TOA-150B – 150 mm apochromatic telescope, tube only

The Takahashi TOA-150B is an apochromatic triplet refractor with two ED lenses, featuring a 150 mm aperture and a focal length of 1,100 mm (f/7.3), designed primarily for deep-sky astrophotography. Its focal length is ideal for observing galaxies (M51, M101, the Leo Triplet), planetary nebulae such as M27, and globular clusters, with a good level of detail. At f/7.3, its standard aperture ratio requires slightly longer exposure times, but in exchange delivers very fine star points.

With an APS-C camera featuring 3.76 µm pixels (Sony IMX571 sensor), you get approximately 0.71″ per pixel for a field of view of 1.2° × 0.8°. This is a fine resolution: under moderate turbulence, 2×2 pixel binning or a reducer will produce rounder stars. With the 0.7× reducer, the resolution increases to 1.01″ per pixel and a field of view of 1.7° × 1.2°.

Yes, whenever you're using an APS-C or full-frame sensor: like any uncorrected triplet lens, it has a slight field curvature that stretches the stars in the corners. Dedicated correctors: Takahashi TKA32587S: TOA-645 corrector kit for TOA-150 ; Takahashi TOA-35 - 0.7× focal reducer for TSA/TOA (equivalent focal length of 770 mm, f/5.1).

275 mm (metal back); 117.5 mm with TOA-35FL; 56.2 mm with TOA-645FL; 62.5 mm with TOA-35RD 0.7×. This focal length is measured from the thread to the sensor, including rings, filter wheel, and filter drawer: adhering to this measurement down to the millimeter ensures that stars remain round in the corners.

The tube weighs about 15.2 kg; with the camera, filter wheel, and guide scope, expect it to weigh around 16.7 kg: you’ll need a heavy-duty mount with a capacity of over 25 kg for astrophotography, ideally mounted on a fixed pillar. A refractor requires no collimation: once balanced, it’s ready to use as soon as it reaches operating temperature. At 111 cm long, it requires a spacious storage case.

Yes, as a bonus: with an angled mirror and an eyepiece, it provides high-contrast, color-accurate images of the Moon, the planets, and double stars, up to about 300×.