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Pt.3: The more I write the more new stuff occurs to me that I have not already covered.
Another image of the side view with the 67° Brewster Angle [eyepiece viewing angle] drawn in.
Note the hex socket head screws in the slotted recesses: These are for aligning [or collimating] the prism in its housing. By this means the prism tilt can be adjusted to make the input and output beams concentric with the tubular adapters.
Here I have rotated the image by 57 degrees to show the eyepiece angle at my maximum, local, solar altitude, at lunchtime, in high summer, here at 55N. I can't see any problem.
Relative size compared with a 2" star diagonal in their storage box. The star diagonal felt absolutely huge when it first arrived in the post. Now it is, itself, dwarfed by the Lacerta solar prism.
The Lacerta probably weighs twice as much. Mostly thanks to the hefty plates from which it is constructed. A simple, bolt together solution, involving CNC machines but no expensive castings. It can be easily dismantled if necessary for cleaning or modification. Rumour has it that these units are made in Hungary.
Here is the Lacerta dangling from my old, Vixen, refractor, 2" focuser on a heavily overcast day. Well, you have to practice, when you can, don't you?
No doubt more pictures will follow when I can actually fit an eyepiece to the prism. Delivery of an M48 to T2 adapter and T2 to 1.25" receptacle from TS expected tomorrow. Their same-day dispatch, via UPS, is amazingly quick. Two days from ordering from Germany items are delivered to my home in Denmark.
Here is the screw-in 2" filter holder & 48mm threaded adapter. The rotatable filter holder with Baader 2" polarizing filter and M48 male thread is inverted to show the layout.
The adapter will normally be rotated to the required angle for desirable dimming and locked with the three thumbscrews. An eyepiece receptacle is attached to the M48 x 0.75 thread not shown.
M48 to eyepiece adapters are available in 1.25" and 2" sizes from TS amongst other dealers. M48 x 0.75mm pitch is the standard 2" filter thread.
The 2" filter holder now inverted. Shown with ND3 filter installed by the factory. Already covered in dust and only one day out of the packet. I keep a rubber bulb, lens blower in the observatory.
The final image [right] shows both components the correct way up. The M48 male thread is on top of the rotatable, polarizing filter holder.
The Lacerta probably weighs twice as much. Mostly thanks to the hefty plates from which it is constructed. A simple, bolt together solution, involving CNC machines but no expensive castings. It can be easily dismantled if necessary for cleaning or modification. Rumour has it that these units are made in Hungary.
No doubt more pictures will follow when I can actually fit an eyepiece to the prism. Delivery of an M48 to T2 adapter and T2 to 1.25" receptacle from TS expected tomorrow. Their same-day dispatch, via UPS, is amazingly quick. Two days from ordering from Germany items are delivered to my home in Denmark.
The adapter will normally be rotated to the required angle for desirable dimming and locked with the three thumbscrews. An eyepiece receptacle is attached to the M48 x 0.75 thread not shown.
M48 to eyepiece adapters are available in 1.25" and 2" sizes from TS amongst other dealers. M48 x 0.75mm pitch is the standard 2" filter thread.
The final image [right] shows both components the correct way up. The M48 male thread is on top of the rotatable, polarizing filter holder.
Click on any image for an enlargement.
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