How do I convert a 240 -420 Symmar?

[John Jones]

I have a Symmar 240-420 convertable but have forgotten how for convert it. Do I remove the front element or the rear?

Thanks for answering such a stupid question.

John

[Chad Jarvis]

The front.

[Kevin Crisp]

Not such a stupid question, see how many of the professional sellers on Ebay have it backwards. Exposing the shutter blades to the outside just seems "wrong," I guess, so they assume you take the back off.

[Dave Willison]

Don't forget to read the corrected aperture numbers after you remove the front element. I have a 300/500mm convertible Symmar and the shutter has two sets of color-coded numbers: white for 300mm and green for 500mm. I seldom remove the front element but I'm always getting messed up by the two sets of numbers! Also remember that you will need more bellows draw to use the rear element and that convertble lenses have the reputation of loosing sharpness when elements are used separately.

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