Lens mount help

[Ibcus]

Does anyone know what mount this lens is?
It's a Sigma 400mm f/5.6 APO, manual focus and manual aperture.

Is there an adaptor to make it fit my Sony a550?

This is the full lens

So far I've been told it's a Minolta MD/MC and a Nikon AIS.

 

[heyho]

I'm sure somebody here will know, but it has no electrical contacts, so something fairly old I'd guess.

The only decent lenses I've seen used on Sony DSLRs are M42 with glassless adaptors, others like the minolta MD require an adaptor containing additional glass to achieve infinity focus, hence the reason people stick to M42 for manual lenses.

 

[scottthehat]

i would say its a pentax mount(pka).