Anat and I have the two scopes mounted side-by-side on his Losmandy G11 mount and we did some casual visual tests. To minimise any other variables in the optical train, we use the same diagonals (AstroPhysics Maxbrights) and eyepieces (TMB Supermonocentrics, ZAO-IIs). And to maintain similar magnification, we use the Supermono 5mm on the TMB 152/1200 to get 240x and Supermono 6mm on the AP 155 EDT to get 233x. To improve the focusing on the TMB 152/1200, I added the Orion Helical Fine-Focusing Adaptor which does indeed help to achieve correct focus position for observations at high magnification. The AP 155 EDT is using a new FeatherTouch focuser.
Looking at the same target (Mars, Trapezium etc) each of us took a few minutes to compare them back and forth. Four other guys also took a look and said they did not see a difference. At first glance both scopes do indeed give the same excellent optical performance. Visually I observed only very minor differences: slightly brighter in the AP, slight warmer tone in the TMB (cooler tone in the AP), and better light control of veiling glare for off-the-edge-bright-object in the AP. These differences are very subtle, like splitting hair. The poorer light control in the TMB 152 is probably due to the Orion flex-shield used as dewshield for the TMB 152. The image crispness, resolution of planetary details, colour correction and the overall image contrast generally seemed to be the same in both scopes.
The seeing was quite good on most nights. On one occasion approaching dawn, I was able to observe Mars with clear and sharp details of both polar caps and Syrtis Major at 558x magnification through the AP 155 EDT with a Pentax XO 2.5mm eyepiece.
In spite of the presence of some thin high clouds on most nights, the sky transparency is still very good. My wife Siti had no problem counting 15 stars in the Pleiades at the zenith with her naked eyes using just direct vision. I only managed ten stars with direct vision and three more with averted vision, giving a total of 13 stars but this is still my personal best record.
![[smilie=work.gif]](./images/smilies/work.gif "work")
I just managed to translate the review into Chinese.
very,very impressive.
