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Tuesday 2nd June. 72F high. Warm and sunny.
I decided to dig out my original "universal digiscoping adapter" for my old, Vixen 90/11 achromatic refractor.Without the adapter I had no photographic reference point to compare with the 85mm Vortex Razor and the Vortex PS-100 camera adapter. Though I could buy a suitable T2 threaded, clamping cup from T-S for the PS-100. They do a whole range. See below.
The image shows heavy vignetting on the 90mm f/11 Vixen with 32mm Meade 4000 eyepiece. 12mm zoom on the camera gives about 34x. [1000/32 x 12/11] More camera zoom will push the bright image right out to the corners but increase the magnification.
The Vixen uses 1.25" standard, astro eyepieces. I have a collection of Meade 4000 series eyepieces. Mostly bought secondhand in good/as new condition. These provide pleasing views but are not the last word in wide field of view.
My memories of my original digiscoping adapter's foibles had not grown dimmer with time. The fact that you have to loosen the "master" clamping knob to make vertical or horizontal movements is a handicap. Nor did it exclude light between the eyepiece and camera lens like a cup-shaped adapter. The vertical adjustment knob is far too small and hidden in the extended lower casting. Making adjustment unnecessarily difficult and pointlessly bulky.
The camera platform is of sturdy plastic but as slippery as hell! My square of bicycle, inner tube was still in place. Pierced by the camera [tripod] clamping crew. The rubber provided the vital friction to stop the camera squirming about as the camera's [tripod] fixing screw was tightened.
In comparison, the Vortex PS-100 adapter is quite a sophisticated bit of kit. The Vortex is all metal and uses one bolt to hold it together after adjustment for alignment. It uses a front plate with a slot to allow sideways and vertical adjustment all in one go. Don't worry, you get used to it.
Once aligned and tightened onto the PS-100's rubber stripped platform, the camera can be removed and replaced at will. The trick was to fix two, hex socket head screws as stops for the base of the camera body. Press the camera gently against the stop screws and re-tighten the tripod screw and alignment is almost perfect every time. No more fiddling like there is with the "Universal" adapter. I suppose the PS-100 is almost universal.
The PS-100 is far less bulky too. In fact you could saw off most of the PS-100 camera platform if you don't need it with your own compact camera. That would save some weight and be much easier to fit into a pocket or camera kitbag/rucksack pocket.The [discontinued] Vortex camera adapters sell for about £65 equivalent at Vortex dealers but still needs a clamping eyepiece 'cup.' Readily available in several size ranges from Telescope-Service in Germany. They have an unbelievable range of adapters. Including threaded for direct attachment to specific spotting telescopes. Their website is also in English if you click the correct flag at top right.
Cheapskates, like me, could use a piece of suitably thick, alloy angle profile instead for a camera platform. Though you'll need to make slots and cut an 8mm[?] crew thread for clamping the front plate. No big deal if you are a competent metalworker. The PS-100 uses an American screw thread so you'll need to find a more suitable socket head screw if you are universally metric.
BTW: The universal adapter's eyepiece is fixed into a Baader 45° terrestrial diagonal in these pictures. This provides correct views L-R & Erect on astronomical refractors. Making them into more typical bent spotting scopes. But without their advantages of shortness, lightness and shock and weather proofing. The downside is that the Baader diagonal uses up a lot of GPL [glass path length] unless you use a GPC [glass path corrector] a sort of Barlow negative lens. Which helps to throw the focus further out and compensates for the lack of inward focus on a typical spotting scope. And some astronomical refractors.
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