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Baader FlipMirror II Star Diagonal

Baader FlipMirror II Star Diagonal

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Baader FlipMirror II Star Diagonal

# 2458055

€ 195.00 Price excl. German VAT tax (19%): € 163.87

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Instruction Manual: Baader FlipMirror II Star Diagonal

Baader-FlipMirror II Star Diagonal (BFM II) with three ports:
- Straight-through (S52, M48 and T-2 on both sides) for full-frame camera, spectrograph, or other instruments
- Adjustable T-2 thread on top for eyepiece clamps, video modules (up to 32 mm image circle) or even a binoviewer
- Bottom flange for the optional Off Axis Guider for Baader FlipMirror II (BFM-OAG) (#2956951, € 98,-) or for an optional calibration lamp for quick calibration of spectra without removing the spectrograph
Precise surface-mirrored flip mirror with multi-layer Al coating, for high-resolution images with cameras with small pixels
The back of the flip mirror is also Al coated and masked to direct the light of an optional calibration lamp onto the slit of a spectrograph
Enables precise adjustment of all light paths
Shortest possible overall length for any application – compatible with a large number of adapters from the Baader Astro T-2 system, the M48 system and the UFC system (Universal Filter Changer)
Rotatable M48 connection rings made of hardened, stainless steel on front and rear, backlash-free adapted to the BFM housing. Can be fixed in the optimum position to rotate any accessory around the optical axis.
Prepared for an optional toothed belt for motorization (e.g. by Steeldrive II motor focuser with Controller (#2957165, € 595,-) ) – basic requirement for image acquisition, guiding and spectroscopy in remote observatories

Product Questions

In order to use the OAG port at the base of the flip mirror, the prism can only go so high before it will hit the mirror when ‘down’. If your connection to the telescope relied on a 1.25” nosepiece rather than a 2” / T2 /M48 connection, would the light ever reach the prism as it would be too low to pick up any light?

Question by: A Bell on Mar 20, 2020 9:33:00 AM | 1 Answer(s)

Can the Flip Mirror 2 be used with the Celestron Edge HD 11 and what adaptor is needed to attach it to the telescope back?
Thank you

Question by: Dick Lerski on Jun 29, 2020 5:45:00 PM | 1 Answer(s)

I cannot get the image in the eyepiece to center. I'm using the Baader Focusing Eyepiece holder. I have moved the adjustable T2 ring to its limit, but the image when centered in the camera is at the edge of the field of the eyepiece. Ideas?

Question by: Peter K. Detterline on Mar 25, 2020 1:50:00 AM | 1 Answer(s)

I have a Vixen VMC-200L, Vixen 50mm 2" ocular (with Baader skyglow filter), a ZWO ASI183MC camera, and a ZWO ASI120MC-S camera. Along with the Baader Flip Mirror Diagonal, what components do I need to mount the ocular on the top port, the ASI183 camera on the axial port, and the ASI120 camera as an off-axis guider?

Question by: WeBMartians on Jan 8, 2021 10:07:00 PM | 1 Answer(s)

This depends on the field stop position of the eyepiece and the backfocus of the cameras.
For the eyepiece on the upper port, we'd recommend
#2956242 M42i x 0,75-ClickLock (Astro T-2 System) with a height of 36,6mm.
Please note that the upper port is limited by the diameter of the T-2-thread, so it is a little bit less than 40mm, and there will be some vignetting with 2"-eyepieces with long focal lengths.
For the camera, you can use e.g.
#2956220 SC / HD (2")-Clicklock (5" SC, 6" SC/HD, 8" SC/HD and 9¼" SC)
with a height of 47mm.
If I understand the description of ZWO correctly, the larger camera has 6mm of backfocus when used with either T-2 or a 2" nosepiece; the smaller camera should be similar and also include a 2" nosepiece (if doesn't, but has got a female T-thread, you can use Baader 2" nosepiece to T-2 / M48 # 2408150; if it has got only a 1.25" nosepiece, there is Baader Pushfix Reducer 2" to 1¼" # 2408151 with only 1mm of optical height).

We'd recommend to use these two clamps and to determine the focus position of the eyepiece. You shouldn't need to insert it completely into upper port, as that clamp is shorter. If desired, you can add T-2-extensions later to get to the right distance. Or you focus your telescope now with the cameras to find out how much the focus differs between eyepiece and cameras, then you can determine the required T-2-extensions in advance.

For connection to the telescope, we'd need to know the available thread at the telescope. T-2 or M48 work out of the box, for other threads, an adapter would be required.

For further information, please also take a look at this blog post: https://www.baader-planetarium.com/en/blog/using-the-flipmirror-the-correct-working-distances/

Answer by: Baader Web Team (Admin) on Jan 11, 2021 3:54:00 PM

-2

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I would like to use your "flip mirror" as a ligth sources selector with my leitz microscope (LED cool ligth or halogen one); to do this I would like to replace the adapter rings with Leitz ones on two sides of the unit; the third one will be used for straigth connection to microscope inlet (by a locked coupling ring).
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.
Best regards

Question by: marco fiorentino on Sep 18, 2020 12:47:00 PM | 1 Answer(s)

I have a Skywatcher 150/750 PDS with a back-focus of 86mm. This Newtonian reflector is optimized gor astrophotography. Flip mirrors are generally not compatible with reflectors. However, in this case, given the optical path of the Baader flip mirror, would it be possible to use it on my scope? If so, how? Thank you.

Question by: JE Friedman on Jan 29, 2021 11:55:00 PM | 1 Answer(s)

I’m trying to build my optic train for a Nikon Z6 and an eyepiece on a Celestron 8” SCT (non EdgeHD). As I understand it, the back focus for the telescope is 127mm (5”). If I connect the OTA via the baader short adapter, what adapters do I need on both the camera train and the eyepiece train?

Question by: Jonathan on Jan 14, 2021 6:10:00 PM | 1 Answer(s)

Lets start with the camera:
- Nikon Z6 - 16mm
- Baader Wide-T-Ring Nikon Z (for Nikon Z bajonet) with D52i to T-2 and S52 # 2408335 (8.3mm)
- optional Reducing piece S52 / M48 # 2958552 (zero length) (for a wider clear aperture; not necessary, if you use T-2 on the telescope side)

The field stop of the eyepiece should be in the same distance from the FlipMirror as the camera sensor. That's ca. 24mm, if you attach the Wide-T-ring directly to the FlipMirror. Then you can use
- Baader Focusing Eyepiece Holder 1¼" / T-2 (T-2 part #08A) # 2458125, 29-35mm for the eyepiece
and
- Baader T-2 / 7.5 mm Extension Tube (T-2 part #25C) for the camera # 1508155
This gives you a working distance of 31,5mm for the camera and 29-35mm for the eyepiece. With this setup, you should reach focus with most eyepieces - usually, the field stop is at the transition between eyepiece body and 1.25" nosepiece, but it can vary. (We all know, that eyepieces are not parfocal...)

The length of the setup is then:
31,5mm for camera (and eyepiece)
59mm for Baader FlipMirror II Star Diagonal # 2458055 when used with T-2
15mm for Baader T Adapter (BTA) for SC and MAK Telescopes (T-2 part #21) T-2 Part #: 21 # 2408160
=> 105,5 mm

Optimum back focus is 127mm, so you need an additional 21.5mm extension, e.g.
Baader VariLock 29, lockable T-2 ExtensionTube 20-29mm with spanner tool (T-2 part #25Y) # 2956929,
if you want to be precise. (a 20mm extension should work good enough, and there is always Set: T-2 Fine-Adjustment rings (0,3 / 0,5 / 1 mm) - Aluminium #2457910) If you want to use the Off Axis Guider, you should place one 211mm-extension in front of the camera and one in front of the eyepiece holder, this will give you more back focus fur the guiding camera. If you don't use the off-axis-port, you can save money and put the extension between flip mirror and telescope. Fortunately, a Schmidt-Cassegrain is a userfriendly telescope, so that you don't have to keep to distance to a tenth of a millimeter.

Answer by: Baader Web Team (Admin) on Jan 18, 2021 1:43:00 PM

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What attachment would I need, to be able to screw the flip mirror directly to a Celestron CPC 1100? Also for a Celestron 8” Evolution.

Question by: William P Johnson on Jul 28, 2020 8:49:00 PM | 1 Answer(s)

I have a Celestron C8 with f6.3 Focal Reducer [FR]. This gives a required backfocus of ~ 105mm from the rear of the FR to the imaging camera sensor. I'm using the BFM-OAG with a ZWO-mini as guide camera, but cannot get the guide camera backfocus to 105mm from the rear of the FR. Is this possible please?

-1

Question by: Tim Aldworth on Dec 5, 2020 10:25:00 PM | 1 Answer(s)

I have a Meade LX90 with the Peterson Eyeopener 2” conversation. This allows a 2”diagonal or lens to be inserted.
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?

-2

Question by: Peter on Nov 17, 2020 6:33:00 AM | 1 Answer(s)

To attach the BFM-II to a 2" eyepiece clamp, you can use 2" / S52 Nosepiece # 2958551

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.

Answer by: Baader Web Team (Admin) on Nov 17, 2020 10:42:00 AM

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Description

Details

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

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Specifications

Additional Information

Manufacturer	Baader Planetarium
SKU (#)	2458055
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

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