Focal Reducer/Field Flattener for the new Stellarvue SV80A Doublet Apo. This IS NOT for the SV80ST Triplet.
This reducer/flattener is optimized for our SV80 Access doublet lens. The flattener inserts into the 2" focuser. The 0.8X focal reduction converts the 80 mm f-7 into an f-5.6 with a focal length of 448 mm.
This reducer/flattener has a standard 42 mm filter thread and M48 thread on the opposite end. Standard 2" filters can be added to the reducer/flattener when imaging. The backfocus of the unit is 55 mm.
If you are using a CCD camera, an additional set of extension tubes may be needed depending on the backfocus of the camera. You need to know how much distance there is between the cameras T-thread and the ccd chip. It is important that the distance from the back of the field flattener to the chip be maintained at 55 mm. If the ccd camera has a backfocus of only 35 mm, a 20 mm extension will be needed.