2015/06/29

A good partner of APM-TMB 105-650: Borg 7704 Super ED Reducer

A long waited Borg 7704 Super ED reducer first light. It is a discontinuous model and I bid it from a Japan website http://www.buyee.jp/. It turns out that 7704 works perfectly with my APM-TMB 105/650. Although the back focus of Borg 7704 was not fine-tuned and default value was used, the stars at the extreme corners were reasonably sharp. There was more distortion at the lower left corner. It takes me sometimes to tune it anyway.

Date: 15-16/6/2015
Location: Pak Tam Chung, Hong Kong
APM-TMB 105/650 with Borg 7704 @F3.9, AVX, D1, 5DII, MGEN II

M8 + M20 : ISO 1600, 3mins x 25, Dark, Flat, Bias, uncropped



M16 + M17: ISO 1600, 3mins x 9, Dark, Flat, Bias, uncropped