Ektar wide field - what's this ring for?

**bill_1041** · 29-Jan-2002, 20:40

Just acquired a 250mm 6.3 Ektar Wide Field. There's a removable ring that screws into the filter threads on the front element - what's the ring for? Maybe to pr otect the threads when I'm not using a filter??

Thanks in advance - Bill

**David Haynes** · 29-Jan-2002, 22:31

Bill,

It's a retaining ring for an unthreaded, drop-in "series" filter. Sorry, but I can't remember which series filters the WF Ektar uses, but they should be available from Tiffen, etc., but for a price.

**John Hicks** · 30-Jan-2002, 02:28

I'll give a WAG of series 8...but that may be entirely wrong. Anyway, if you can fit a screw-in filter be careful because the thread pitch of the series retaini ng ring and a screw-in filter is slightly different. Some filters screw in fine and others bind and can strip threads if forced.