TS Optics Apochromatic refractor AP 70/474 OTA (61436)

The TS Optics Apochromatic Refractor AP 70/474 OTA is a premium small refractor highly valued for both astrophotography and visual astronomy. With a 71 mm aperture and 474 mm focal length, it provides a focal ratio of f/6.8, making it versatile for a range of astronomical applications. Its advanced four-element Petzval optical design, using FPL53 glass, delivers excellent chromatic correction and a wide, fully illuminated field—ideal for use with full-frame cameras. The sturdy 2.5" rack-and-pinion focuser features 1:10 micro-reduction and a 360° rotator, supporting heavy imaging accessories up to 4 kg with secure locking.

This telescope is especially recommended for use with cooled CMOS cameras for deep-sky imaging, but it also excels in visual observation, offering sharp and high-contrast views from 10x to 200x magnification. The AP 70/474 stands out as a strong alternative to other high-end compact refractors and is suitable for advanced users seeking optical quality and flexibility.

TS Optics is a brand of Teleskop-Service.

Specifications

Optics

• Type: Refractor

• Optical design: Apochromat (four-element Petzval, FPL53 glass)

• Aperture: 70 mm

• Focal length: 474 mm

• Aperture ratio: f/6.8

• Resolving capacity: 1.97 arcseconds

• Limiting magnitude: 11

• Light gathering capacity: 100

• Maximum useful magnification: 140x

• Tube weight: 3.2 kg

• Carrying length: 450 mm

• Coating: Multiple coatings

• Tube construction: Full tube

• Fully corrected field: 32 mm

Focuser

• Type: Rack and pinion

• Eyepiece connection: 2 inches

• Camera-side thread: M54

• Backfocus: 135 mm

• Free aperture: 64 mm

• Ring clamp: Yes

• Fine focus gear reduction: 1:10

• Adjustment range: 70 mm

• 360° integrated rotator

• Maximum load: 4 kg

Mount

• Type: OTA (no mount included)

Included accessories

• Finder scope: Not included

• Tube clamps: Yes

• Prism rail: Vixen-Style

• Dew shield: Yes

• Integrated corrector: Yes

• Transport cases: Yes

• Eyepiece adaptor: 2" / 1.25"

Area of application

• Astrophotography: Yes (very good, supports full-frame sensors)

• Moon and planets: Yes

• Nature observation: No

• Nebulae and galaxies: Yes

• Sun: No (only with appropriate sun filter)

Recommended for

• Beginners: No

• Advanced users: Yes

• Observatories: No