Do not you have a room with two sensors but do not want to give up this privilege …… no problem the brand new off-axis (Off Axis Guider) of LBastro will allow the same performance of a CCD that incorporates a second device dedicated to driving .
Proxyma OAG crafted by Technical LB, is adaptable to any optical configuration dedicated to astrophotography of the deep sky.
Proxyma OAG combines two useful caratterestiche today much sought ….. off-axis total rotation, independent of room.
Main technical features:
– OAG rotation and independent room to 360 °
– Single block for each rotary system
– Outer circles graduated
– Free surface on both sides of more than 4,000 mm square
– Attacks f / f M72 (Takahashi standard)
Total compatibility with any commercial connection (with optional fittings)
-prisma bright 10×10 mm (certified reflectance of 98%) longitudinally adjustable (depending on the shooting sensor)
– Stem and built-in prism interchangeable
– Attachment of type T2 or Lodestar guide camera (standard) exchangeable
– Fine adjustment of the guide chamber both for the fire that for the positioning of the axes (x, y)
– Weight 900 grams
All users who use the SX Lodestar remember that the “metal back-focus” of the CCD is 12.5 mm (distance of the sensor from the external metallic stop).
If you have then this room or rooms of driving “back-focus”, using the ns. Proxima OAG in the standard version (with attachment “C”), the focus of the “guider” will be screened at about 62 mm from the surface of the internal prism driving off-axis.
If using driving rooms with back-focus more (eg. ST402ME T2 back-focus attack ..17,5 mm ..) the position of the guide sensor will be about 67 mm.
The OAG focheggiatura the Proxima system will allow you to find in every situation the migliorre focus position of your guide camera.
With appropriate fitting T2 (in the alternative to “C”) the back-focus of the guide sensor drops to about 60,5 mm (if the metal back-focus of the guide chamber is 12.5 mm).
The fire will be sought between 60.5 mm and 66.5 mm.
Back-focus with DSRL
Generally when using as imaging camera a DSLR, the distance between the plane of the CCD sensor (illuminated surface) and the outer metallic stop (attaccco ring T) is about 55mm (44 mm due to the natural draft of the room and about 11 mm thickness T of the ring).
The following measures will be added to the said fixed “back-focus”:
15 mm determined from the fitting (M72-T2) required for the connection between the ring T (EOS) and off-axis (the 15 mm are calculated to prevent the SLR flash will not interfere with driving off-axis)
40 mm determined by the thickness of the off-axis Proxima OAG
mm 3 if the telescope to be connected is for example a Takahashi FS102 (for other optics must be evaluated for the fitting length)
In the case of telescopes with moderate back-focus, we invite you to check in advance the maximum distance of the focus position in each configuration (focal ratio) in which you plan to use them (focal reducers, flattener etc.).
Recall that the use of any fittings 2 “(nose) prepended to the off-axis, can determine vignettattura in the presence of gerose size sensors.