Astro T-2 System Specs

Part # Description


Path Length (mm)


Objective End

Threads/Size, Eyepiece



Auxiliary Threads

MAX-1 T-2 Maxbright Mirror Diagonal 54 T-2 (i) T-2 (e) -
AMICI Deluxe Amici Diagonal 49 * T-2 (i) T-2 (e) -
T2-01B T-2 Prism Star Diagonal 42 * T-2 (i) T-2 (e) -
T2-01C T-2 Prism Star Diagonal 38.5 * T-2 (i) T-2 (e)  
T2-03 Adapter 36.4/T-2 (Takahashi/Vixen Small) 0.5 M36.4 x 1 (e) T-2 (e) M34 (i)
T2-06 T-2 Quick Changer 11 T-2 (i) Bayonette (i) -
T2-07 T-2 Change Ring 4 Dovetail (e) T-2 (e) Ø38mm(i)
T2-08 Clicklock Eyepiece Clamp 1.25"/T-2 32-38 ** T-2 (i) Ø1.25" (i) T-2 (e)
T2-09 Zeiss M44/T-2 Adapter (Inner) 14 T-2 (i) M44 x 1 (i) -
T2-10 Reducer 1.25"/.965" 6.5 Ø1.25" (e) Ø0.965" (i) M28.5 (i)
T2-12 Takahashi Converter M43/T2 (fits Takahashi Focusers) 1 M43 x 0.75 (e) T-2 (e) -
T2-12b Zeiss Position Circle 18 M44 x 1 (e) M44 x 1 (i) -
T2-13 Zeiss Camera Adapter M44/T2 5 M44 x 1 (e) T-2 (e) Ø38mm(i)
T2-14 Nosepiece 1.25"/T2 0.5 Ø1.25" (e) T-2 (e)


M34 (i)

T2-15 Deluxe Reducer 2"/1.25" 14 Ø2" (e) Ø1.25" (i) M48 (i)
T2-16 Nosepiece 2"/T2 2 Ø2" (e) T-2 (e)


T-2 (i)

T2-17 2" Deluxe Clamping Eyepiece Holder 53 UNC 2" (i) Ø2" (i) -
T2-21 Short T-Adapter (16mm) 16 SCT 2" thd (i) T-2 (e) Ø38mm(i)
T2-22 Adapter M43/T2 (Vixen) 2.5 M43 x 1 (e) T-2 (e) Ø38mm(i)
T2-23 Russian Camera Adapter M42/T2 7 M42 x 1 (i) T-2 (e) Ø38mm(i)
T2-25A T-2 Extension Tube 15mm 15 T-2 (i) T-2 (e) Ø38mm(i)
T2-25B T-2 Extension Tube 40mm 40 T-2 (i) T-2 (e) Ø38mm(i)
T2-25C T-2 Extension Tube 7.5mm 7.5 T-2 (i) T-2 (e) Ø38mm(i)
T2-26 Inverter T-2/T-2 0.0 T-2 (e) T-2 (e) Ø38mm(i)
T2-27 Adapter 2"/T-2 0.5 ** SCT UNC 2" (e) T-2 (e) M48 (i)
T2-28a Expanding Ring T-2/2" 1 T-2 (I) UNC 2" (e) -
T2-29 Expanding Ring T-2/M48 2.5 T-2 (i) M48 (e) -
T2-30 Focusing Ring Collar   FR-4 9.9 1.25" (i) - -
T2-32 2" Deluxe Clamp 17      
T2-34 T-2 Conversion Ring 10 T-2 (i) T-2 (e) -
T2-35 T-2 Locking Ring 2 T-2 (e) T-2 (e) -


(i) = Internal Thread

(e) = External Thread

T-2 Thread = M42 x 0.75


* Typical Value, measured at f/5.5.  Effective Path Length will be slightly different due to optical effect of prism on path length (less path length is required for scopes faster than f/5.5, more for longer scopes).


** When using the T2-08 plus T2-27 with the Herschel Wedge, the range of clearance from top of the T2-08 to the filter glass surface is 38-44mm.