Stellarvue Large Photographic Field Flattener For 2.5" Focusers
48 mm T-Thread
This Stellarvue Large Photographic Field Flattener is made for their f/7 refractors. It threads to the rear of the 2.5" Stellarvue or Feather Touch focusers. This flattener uses an over-sized 48 mm camera attachment thread. Using one of the over-sized 48 mm T-rings, a DSLR camera may be used with this field flattener.
A field flattener lens is normally required to provide a completely flat focal plane to match the flat surface of a CCD or other electronic imaging chip in a camera. Even though a particular telescope is designed to be Apochromatic and has the highest possible theoretical image resolution, its focal plane will usually exhibit some curvature of field. While this is not an issue for visual observing, it would be a problem for imaging.
This Stellarvue Large Photographic Field Flattener For 2.5" Focusers - 48 mm uses an oversized thread to attach to the camera, which is compatible with DSLR systems. This provides a completely threaded mounting solution for cameras when using a 2.5” focuser. When using a CCD astro camera, spacer rings and/or extension tubes may be required, depending on the exact location of the CCD chip behind the front attachment component of that camera. Some cameras have a short back focus. If you are not sure about your particular requirements please contact your dealer or call Stellarvue to discuss this matter in more detail.