To meet the needs of the ever increasing CCD size used in astro-imaging, Optec has designed a larger cousin to the IFW 2-inch. The new IFW 3" (full 3-inch clear aperture) supports a large variety of filter sizes with the ease of selection that is the hallmark of the IFW 2-inch. Three different types of interchangeable filter wheels are available: 58mm square with 5 positions, 50mm square with 6 positions and 50mm round with 9 positions. The 58mm square filters are a new standard available only from Optec. All filters are mounted using convenient delrin plastic tabs and spacers.

When used with the 3-inch couplings to the telescope and instrument package, either 58mm or 50mm square filter wheels can be used. These adapters and couplings are the same as what is used with the TCF-S3 and the Pyxis 3-inch instruments. Removing and installing a different wheel is as easy as with the IFW 2-inch. A side door is opened and the wheel removed after releasing the center axis hub. After the HOME serial function or HOME button is pressed, the wheel ID is identified and the new stack of filter names are available to the control program or display on the control box. For the 50mm and 58mm square filters, three filter wheels with unique ID are possible. There are two wheels available for the 9-position 50mm round filters

The 50mm round filter wheels are intended for 2-inch adapters and couplers for both the telescope and instrument package. These adapters are the same as what is used with the IFW 2-inch and TCF-S products. The 50mm round filter wheel is not intended for use with the 3-inch adapters.

Note: The IFW 3" is a massive unit that measures 10-inches on a side and is 2.5-inches thick including both the telescope and camera side adapters. At 7 pounds, a large telescope with capable telescope mount is required. A variety of telescope mounts are available to fit, and a very complete line of 3-inch drawtube adapters are available.