NAKOH 60GT 测试报告 NAKOH 60GT Test Report (English at lower part of this post)

NAKOH是一个日本新望远镜品牌，星河科研社月前获邀成为香港独家代理，首款产品60GT折射镜、0.65x减焦镜及1.0x平场镜，为市场上最高修正度的目视及摄星折射镜之一，

早前进行星空测试，结果十分理想。

1. 这台镜的机械造工十分好，如业界里常叫的"built like a tank"，三片式APO镜头采用一片日本SD玻璃及一片ED玻璃，官网上的测试样本修正度达97.% Strehl，已是业界里传奇品牌TMB-LZOS的水平了。接上顶级行星目镜TMB Supermonocentric目镜及TMB 1.8x ED barlow，织女星是纯白没色差的，木星云带及大红斑对比度非一般折反射镜能比，在香港近郊，受惠于这镜的高对比度，一些主要深空天体形态也十分易见。当然，始终口径只有60mm，很难做深入的目视观测，但带出去观察或纪录日月食等天象，则十分理想。

2. 接上Canon Ra全片幅天文相机，试用Bahtinov调焦版，潇洒点用手动调焦，0.65x减焦镜及1.0x平场镜的表现，星点修正度及渐晕(像场边缘失光)情况，一如官网上的参数般理想。这摄星系统完全能覆盖全片幅相机。

可以从以下连结下载参考测试星场，RAW转TIFF

60GT + 1.0x平场镜 + Canon Ra全片幅相机

CR3 raw https://drive.google.com/file/d/1tmuKDokA8Y-thaGQZ-lEIP6ONo8FuzX3/view?usp=sharing

CR3 转 TIFF调高一级曝光 https://drive.google.com/file/d/15Q9I96XabH4jhMBEhXbU1yIUsW1HiXAN/view?usp=sharing

60GT + 0.65x减焦镜 + Canon Ra全片幅相机

CR3 raw https://drive.google.com/file/d/1gqFnjyoKLDZ3duG3ZIqS7LGZHq7X-HwD/view?usp=sharing

CR3 转 TIFF调高一级曝光 https://drive.google.com/file/d/1gWlGWF7nbdUWVx5zSxWfRULfPWxg1fG4/view?usp=sharing

NAKOH 60GT Test Report

NAKOH is a new Japanese telescope brand. Galaxy Scientific Group was recently invited to become the exclusive distributor in Hong Kong. Its first product lineup includes the 60GT apochromatic refractor, a 0.65× focal reducer, and a 1.0× field flattener. The 60GT is positioned as one of the highest-corrected refractors on the market for both visual observation and astrophotography.

We conducted field tests under the night sky, and the results were very impressive.

1. Visual Performance

The mechanical construction of the 60GT is excellent - truly"built like a tank.” The triplet APO objective uses one Japanese SD glass element and one ED element. According to the manufacturer’s test sample data, the optical correction reaches 97% Strehl, which is on par with legendary brands such as TMB-LZOS. When paired with a premium planetary eyepiece (TMB Supermonocentric) and a TMB 1.8× ED Barlow, Vega appeared pure white with no detectable chromatic aberration. Jupiter's cloud bands and the Great Red Spot showed contrast levels that are difficult for typical catadioptric systems to match. Even under suburban Hong Kong skies, the high contrast of this telescope made the structure of several major deep-sky objects clearly visible. Of course, with an aperture of only 60mm, it is difficult to perform very indepth visual observations. However, it is an excellent choice for portable observing or for documenting astronomical events such as solar and lunar eclipses.

2. Astrophotography Performance

The telescope was tested with a Canon EOS Ra full-frame astronomy camera. Manual focus was achieved quickly and effortlessly using a Bahtinov mask. Both the 0.65× focal reducer and the 1.0× field flattener performed as specified. Star correction and vignetting control were consistent with the official specifications. The imaging system fully covers a full-frame sensor with excellent star quality across the field.

Sample test star-field images (RAW converted to TIFF) can be downloaded from the links below:

60GT + 1.0× Field Flattener + Canon Ra (Full Frame)

CR3 RAW https://drive.google.com/file/d/1tmuKDokA8Y-thaGQZ-lEIP6ONo8FuzX3/view?usp=sharing

CR3 converted to TIFF (+1 stop exposure) https://drive.google.com/file/d/15Q9I96XabH4jhMBEhXbU1yIUsW1HiXAN/view?usp=sharing

60GT + 0.65× Focal Reducer + Canon Ra (Full Frame)

CR3 RAW https://drive.google.com/file/d/1gqFnjyoKLDZ3duG3ZIqS7LGZHq7X-HwD/view?usp=sharing

CR3 converted to TIFF (+1 stop exposure) https://drive.google.com/file/d/1gWlGWF7nbdUWVx5zSxWfRULfPWxg1fG4/view?usp=sharing