The TPO 2" f/5 Focal Reducer will help to lower the focal ratio of your optics. The outside thread connection of M48 x 0.75 will fit most 2" eyepieces for visual use, too! Now you can connect your CCD camera and any 2" threaded camera adapter, just by using the TPO 2" Focal Reducer. Guess what? It even allows the connection of most 2" filters, too!
The actual reduction will vary a little over or under 0.5x depending on exactly where the focal reducer is placed in the optical path. The exact focal length specification of this reducer has not been provided by the manufacturer, but we estimate it to be approximately 101-103mm. Hence, the "working distance" of this specific reducer is estimated to be 51mm, i.e., this reducer will provide a reduction of 0.5x when the center of its lens assembly is placed 51mm from the focal plane of the eyepiece or imaging device. Move the focal reducer closer to the eyepiece/camera and its reduction factor will increase. Move it away and the reduction provided will decrease.
By using additional spacers or extension tubes (sold separately), you can vary the amount of reduction you obtain with this reducer as follows:
| Extra Spacer Length |
Nominal Reduction Provided |
| 0" / 0mm |
0.50x |
| 0.25" / 6.4mm |
0.44x |
| 0.5" / 12.7mm |
0.38x |
| 0.75" / 19.1mm |
0.31x |
| 1" / 25.4mm |
0.25x |
TPO Product Number: FR2
- Connects to 2" nosepieces for CCD cameras and 2" threads on 2" camera adapters
- Fits most 2" eyepieces for visual use
- A 2" thread inside to connect with most 2" filters
- Outside thread is M48 x 0.75.
- TPO 2" Focal Reducer - 0.5X
