A long waited Borg 7704 Super ED reducer, a discontinuous model, first light. I bid it from Japan with a relatively high price! It's optics and reducing power, 0.65X on average, is irresistible!
However, after owned it. It is hard to have a chance to try it. It is hard to find time to process the images. Finally I can't wait to learn PixInsight, but have a fast food, Deep Sky Stacker! In addition, I tried to manage several second handed and borrowed equipment together...
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 were more distortion at the lower left corner. It takes me sometimes to tune it.
Date: 15-16/6/2015
Location: PTC
APM-TMB 105/650 with Borg 7704 @F3.9, AVX, D1, 5DII
M8 + M20 : ISO 1600, 3mins x 25, Dark, Flat, Bias, uncropped
M16 + M17: ISO 1600, 3mins x 9, Dark, Flat, Bias, uncropped
圖片附件: M16 M17 105-650 7704 D1 16-6-2015 27m 1600L.jpg (2015-6-29 23:21, 596.51 KB) / 下載次數 75
