http://www.amazon.com/Olympus-200-540-1-45X-Teleconverter-Lens/dp/B00000JHX1 I picked up on of these at a car boot sale ages ago and tried it on a variety of lenses without success, often dreadful pincushion distortion. It appears to have been originally called an Olympus D-1.45x HQ Tele Converter Lens for their Centurion APS film cameras but has re-surfaced as a converter for early Olympus digicams. As the 46mm clip on fitting snaps straight onto the filter threads of the 45-175 I gave it a try and it looks like it may be useful if only for video EFL is 507mm. It is really tiny and light compared to the tcon17 and doesn't look too stupid when fitted. It looks like there are a few still about on Ebay, don't all rush!