Only some teleconverters work well with some lenses, and it is hard
to predict what will work well without a film check. VERY few double
converter combinations work well enough with any lens to warrent even
emergency use - would be better to crop a bit from a good lens-converter
combo. The Nikkor TC300 with a Nikkor TC14C on rear works adequately
with the ED non-IF version of the 300mm F4.5 Nikkor and with some
macro combinations at small stops, but most other combinations are poor
at best. Even a cheapo long lens will generally outperform a
multiconverter setup. Hope this helps.