Short answer: No — there are no practical adapters to use Sony FE (E-mount) lenses on a Sony A99 (A-mount body).
Here’s why:
🔴 Fundamental issue: mount geometry
- The Sony A99 uses the older A-mount (SLT DSLR-style).
- Sony FE lenses are E-mount (mirrorless).
The key problem is flange distance (distance from lens mount to sensor):
- A-mount: longer flange distance
- E-mount / FE: much shorter flange distance
Because of this, adapting FE → A-mount would require the lens to sit inside the camera body — physically impossible without optics.
🔴 What exists (but in the opposite direction)
Sony does support:
- A-mount lenses → E-mount bodies using adapters like Sony LA‑EA5 adapter
- This works because you can add spacing — not remove it
🔴 Theoretical workaround (not recommended)
- You could build an adapter with corrective optics (like a teleconverter)
- But this would:
- degrade image quality
- affect focal length and aperture
- likely lose autofocus
In practice, no mainstream manufacturer makes such an adapter (for good reason).
✔️ Practical options for you
If you want to use FE lenses:
- Move to a Sony E-mount body (e.g. A7 series)
If you want to keep the A99:
- Stick with A-mount lenses
- Or adapt manual lenses from other mounts (many work fine)
Bottom line
- A-mount → E-mount: ✔️ common and supported
- E-mount (FE) → A-mount: ❌ effectively impossible in practice