Takahashi TOA-130S OTA
With its Ortho-Apochromat Triplet (TOA) concept, Takahashi gives a second youth to the refractors of large diameter, often confined with the planetary and lunar observation. Greatest accessibility with the imagery as well as the appearance of increasingly large and increasingly powerful numerical sensors obliges to make these telescopes much more general-purpose and compact, less restricted with planets and observatories.
The TOA-130 associates the extraordinary contrast of the images and the absence of chromatism of apochromatic refractors with a consequent diameter and a reasonable focal distance, allowing a general-purpose use as well for the planetary high-resolution as for deep sky imaging. In this last field, its optical design enables it to fully use the capacities of all imagers of the market (35mm SLR/DSLR or 6x7 cameras but also wide-field CCD imagers).
The TOA-130 is available in S version, with traditional rack-and-pinion focuser, and in F version, with oversized rack-and-pinion focuser (and camera angle adjuster), perfectly adapted to imaging. For this optical tube of 1015mm length, of 130mm of diameter and of almost 10kg, configurations exist on EM-200 or EM-400 equatorial mountings.
The Triplet ED objective
The apochromatic objective with triplet ED of TOA-130 (D=130mm, F=1000mm, F/D 7,7) is assembled in an extremely neat and precise barrel mechanical, entirely adjustable. Collimation is easy to realize and makes it possible to adapt perfectly the optical stresses to the conditions of observation or imaging. The tube has a retractable dewshield.
The two versions S and F are equipped exactly with same optics. Only the rack-and-pinion focuser differs.
The TOA-130S rack-and-pinion focuser
The S version has a traditional rack-and-pinion focuser of 69mm of diameter. The back focus is important. To obtain the exit of the focal point, the refractor is equipped with a focuser extension tube, removable (see the system-charts) and with a 50.8mm traditional one. A balancing counterweight cradle is provided because of the important weight of the objective. For photography, the FL-35 flattener offers a consequent image circle of 40mm diameter.
The TOA-130F rack-and-pinion focuser
The balancing counterweight cradle and the removable extension tube for focuser are not necessary on the F version because the rack-and-pinion focuser, alike FSQ, is much more massive (102mm of diameter). A camera angle adjuster is delivered, included in the focuser. Thanks to this configuration, the F version is resolutely turned towards imaging. It allows more rigid imaging assemblies in particular with CCD cameras of big size, without generating mechanical stresses. Last but not least, this focuser enables it to accept some of the specific accessories of the TOA-150, such as the 645-RD reducer or the 67-FL flattener which offers an incredible image circle of 88mm diameter (60% not vignetted).