72ed mounting and balancing

source: AstroCity.es, Madrid

• 72mm refractor: focal length of 420mm giving f5.8
• field flattener tsflat2: working distance [1]~ 128mm
• dslr: eos700d, back focus 44mm with m48 adpator at 11mm giving 55mm to the sensor
• spacers: 73mm from the shoulder of the ff to the m48 t-adaptor
• dovetail plates: vixen 2 x 130mm, losmandy-celestron 1 x 340mm
• maths: 55 + 73 = 128

    

[1] tsflat2 working distance

♦ focal length < 450   mm: 128 mm
♦ focal length 450-490 mm: 123 mm
♦ focal length 500-550 mm: 118 mm
♦ focal length 560-590 mm: 116 mm
♦ focal length 600-690 mm: 113 mm
♦ focal length 700-800 mm: 111 mm
♦ focal length > 800   mm: 108 mm