Bayonet 58mm convertor? Neat idea or am I being dumb . .
 

I've just read and realised something. I've put off thinking/buying 2X TeleConverter from Century or whovever - but have been put off by the need to "screw" on the 58mm threaded lens. Is there such a thing as a 58mm threaded convertor to give a bayonet option? Or am I missing the plot here? Could it be that the focal plane will be majorly effected, this resulting in manufacturers not wanting to design, construct and retail such a product?

Grazie

Graham,
Not to declare that such a gadget doesn't exist but I sure do not know of one.

Indeed, the location of the adapter with respect to the main lens is a matter of some precision. Those who, for example, mount a filter between an adapter and the lens (for inexplicable reasons) do indeed throw this alignment off by a few millimeters.

Pity - But you don't surprise me.

On another tack, as you make me think, I DO use a filter between the WD58 and the Cammy lens. Not recommended?

Grazie

No, not recommended for the reason, above. But judge its merits for yourself.

What filter do you use and for what reason?

I didn't use a real filter between the teleconverter and my GL1 but I did use a filter with the glass removed in order to minimize wear and tear on the threads. It might have meant more vignetting occurred at wide angle (not that I use that). It might have affected auto-focus a little but not that I noticed.

I have stopped using the intermediate set of threads though and now just mount the lens straight to the camera. No real reason other than a feeling that using the filter might not be the best thing to do.