To be honest, autoguiding is usually used for larger sensors which would be obstructed by a 1,25"-focuser anyway, and most focusers which are strong enough for a flip mirror, a camera, a guiding camera and maybe even an eyepiece are 2"-focusers, so we preferred a larger mirror.
To test this, take a look through the eyepiece and move the mirror slightly up - if the star moves in the desired direction (or contrary to it), then you need to adjust the brass pins. Please see page 11 in the manual (chapter 3 - Adjusting the mirror). If it moves sideways instead, things get complicated. But that's most probably the solution.
Baader SC / HD Ultra Short T-Adaptor, 7mm optical length # 2958500B
to attach it to the T-2-thread of the FlipMirror.
Do you think it is feasible? may you send me a tech drawing with ring holes on the three sides?
I thank you in advance for your kind answer.
I also have a DSLR with the T2 adapter for Astro photography. Can you tell me specifically what additional adapters i will need to connect the flip mirror to the 2” opening on the Meade and to allow 2” eyepiece plus the DSLR?
Please note that the upper port is restricted by the T-2-thread and the diameter of the diagonal. The usable field is 32mm, equal to our 32mm T-2 prism diagonals.
You can screw a standard DSLR with standard T-ring directly to the back of the BFM-II. There are small set screws to adjust the rotation of the camera with a screw driver or an allen key. The distance from the sensor to the flip mirror is then 55mm (the standard flange distance of T-2).
On the upper port, you can use the M42i x 0.75-ClickLock (Astro T-2 System) #2956242 with a height of 36,6mm. Then you need a T-2-extension of ca. 18mm to bring eyepiece and camera to the same focal distance. It might be the best to use the shorter Baader T-2 / 15 mm Extension Tube (T-2 part #25A) # 1508154 and let the eyepiece stick out a little bit, or to use a 7.5mm or 15mm extension between camera and flip mirror and a Vari Lock for the eyepiece holder. We can't give a final anser to this, because not all eyepieces have the same focus position - it is often at the top of the 2" nose piece, but it may vary. For 1.25" eyepieces, you have to take the length of the 1.25"-adapter into account, too. The shortest solution is Baader Pushfix Reducer 2" to 1¼" (T-2 part #15a) # 2408151.
For more about this, please take a look at this article: https://www.baader-planetarium.com/en/blog/using-the-flipmirror-the-correct-working-distances/
You ned to place the field stop eyepiece at the same distance from the BFM-II as the camera; and it is easier to vary the eyepiece positin than that of the camera.
Baader FlipMirror II Star Diagonal
Various ports – variable work
Telescope auxillary instruments cover a wide range of interests, from a sole eyepiece, via camera use, to high end spectroscopy. Unfortunately every telescope just features one exit port. This causes relentless manual exchange of parts in the dark, causing huge time loss, wear on the parts - and "nerves". And whenever you start controlling your telescope remotely - the single port becomes a painful reality.
Improving workflow, especially during astrophotography is the goal set out for the BFM II. This is not just a simple flip mirror but much more, as there are three ports to be put into action.
BFM II makes your single telescope port variable - to suit your various interests.
The FlipMirror II Star Diagonal allows a variety of permanent adaptations to your telescope 1 . Use the rotary knob 2 to switch between the rear port 3 and the top port 4; you can use an optional toothed belt to operate it with a motor (not included). An autoguider or a calibration lamp can be connected to the bottom port 5.
General Function of the FlipMirror II Star Diagonal
The BFM II lets you switch between a straight light path (Position A) for a camera or other measuring instruments and an angled light path (Position B), e.g.
for an eyepiece. The following figure shows how it works. In addition, a calibration lamp for spectrographs or an Off-Axis-Guider pickoff-prism (that is not affected by the mirror position) can be connected at the AUX-port on the bottom
Scope of Delivery of the Baader FlipMirror II Star Diagonal:
- Baader FlipMirror II Star Diagonal – with fine-optically polished, movable mirror
- Laterally adjustable T-2a top ring
- 2x M48i / S52 Dovetail ring made of hardened stainless steel # 2958552
- Reducing ring M48a / T-2i # 2958553
- Reducing ring M48a / T-2a # 2958554
- Inverter ring M48a / M48a # 2958555
- Pin type face wrench for M48 / T-2 and M4 counter nuts
- 3 mm screwdriver for M 4 brass adjustment screws
- 4x hex keys (2.5 / 2.0 / 1.5 / 1.3 mm). The 2.0 mm wrench has a ball head to reach screws even when accessories are mounted by holding the wrench at an angle.
- Bottom flange (laterally adjustable 1mm) for off-axis guide or calibration lamp for spectroscopy
- Dust cap for bottom flange
- 2 x M48 dust caps
- T-2 dust cap
|Optical length (mm)||55 mm with S52, 59 mm with M48/T-2|
|Dimensions||63 x 77 x 69 mm|
|Inner Connection (lens sided)||Thread, Dovetail ring clamp, S52, T-2 (M42 x 0,75), M48|
|Weight (kg)||195 g|
|Inner Connection (eyepiece/-camera-sided)||Thread, Dovetail ring clamp, M48, S52|
|Outer Connection (eyepiece/-camera-sided)||Thread, M48|
|Type of Adapter||Variable|