Astro-Physics considered four primary goals when creating this adapter:
- To reduce vignetting introduced as a consequence of standard 2-inch nosepiece usage on the STL-11000's large CCD chip. This adapter attaches directly to the accessory mounting block of SBIG STL Series cameras.
- To permit easy image framing.
- To preserve the essential distances to the focal plane the Astro-Physics 2.7-inch and 4-inch Prime Focus Field Flatteners require.
- To permit un-vignetted 2.7-inch Photo-Visual Telecompressor (27TVPH) performance with STL, AO-8 or AO-L adaptive optics units when the 2.7-inch to 6 x 7 Outer Bayonet Adapter (ADA2767) is also in use.
ADA672 is the longer 1.93-inch length model. This is the adapter for STL series cameras with the standard 5-position color filter wheel. It positions the STL's CCD sensor at the ideal 3.4-inch distance from the field flattener for pinpoint stars over the large CCD chip. Developed to be used with all 2.7-inch and 4-inch Astro-Physics Field Flatteners from the Traveler's 2.7-inch Field Flattener to the 206EDF's large 4-inch model. The only exemptions to this are the field flatteners made for the 175EDF and 160EDF StarFire Refractors which have their own individual STL camera adapters.
Additional Applications: A whole new world of opportunities for those who own STL cameras as well as AO-8 and AO-L Adaptive Optics Units has opened up with the production of the 2.7-inch to 6 x 7 Outer Bayonet Adapter (ADA2767) when coupled with this longer 1.93-inch adapter or the shorter 1.58-inch adapter (ADA671). (These adapters are not compatible with the older AO-7 model.) Now you can have a unencumbered light path to your STL camera or Adaptive Optics unit in addition to smooth image framing from any telescope featuring a 2.7-inch Astro-Physics female thread. This includes large Meade Schmidt-Cassegrains with the AP ADASCTLM27 substituted for the visual back. Most beneficial of all, however, is that this adapter enables the largest clear aperture available when the AP Photographic-Visual Telecompressor (27TVPH) is used with the STL or AO unit. This adapter may also be used in any light path that does not employ a field flattener and thus does not have strict spacing demands. If spacing is ever a critical issue, the shorter ADA671 adapter may be the better choice. Typically adding extensions is easier than reducing the length of your light path, especially when SBIG AO-8 or AO-L units are being employed since they already greatly increase light path distance. Machined from single pieces of aluminum for strength and stability, this adapter bolts directly to the STL camera's accessory mounting surface. The 2-inch nosepiece is therefore allowed to be detached giving the adapter a much larger opening so that the only conceivable source of vignetting on the CCD chip edges is the camera's own internal filters. Ingenious radius-cut keyhole slots located at the bolt attachment positions let you connect the bolts to the STL safely before mounting the adapter and twisting it into position. Both the ADA671 and ADA672 adapters are CNC precision machined at Astro-Physics' own building and black anodized for a full, lush finish. The contrast in your images is maximized as a result of internal knife edge baffles that are painted flat black.