I read your reaction on the OM-1II and 150-600mm specs. And yes, I too wondered if the OM-1II was juts an OM-1 with software updates and the 150-600mm just the regular Sigma 150-600mm Full Frame lens with Micro Four Thirds mount. I tried to get some answers from my sources and this is what I got:

OM-1II seems to have three hardware upgrades:

• Larger buffer ( I don’t think that would be possible via simple firmware update)
• 8.5 stops IBIS (0.5 stops more than the OM-1)
• Improved haptics and ergonomics

On the nw OM 150-600mm lens:

The OM 150-600mm lens is definitely based on the Sigma lens. When my sources asked OM Digital if this is the same Sigma 150-600mm FF lens the managers siad simply “no”. Without to explain further if the optical design has been adapted to MFT.

A source told me this:

Om-1II has new ND options of computational nd filters

OM-1II specs:

1. Re-branded as OM SYSTEMS (as you know the OM-1 still has the Olympus name on it).
2. Double the internal buffer memory
3. 14bit raw for High resolution mode
4. human AI recognition
5. nd2 nd4 nd8 added as new options of computational nd filters
6. better focusing system

Gear top be announced on January 30 at 6am London time:

1. OM-1II
2. 9-18mm II
3. 150-600mm f/5.0-6.3

One source that was briefed on the new OM 150-600mm 5.0-6.3 lens told me this:

150-600mm (not a pro lens) with stabilization co-work with camera body. I believe the telephoto lens is sigma designed and manufactured from their existing full frame 150-600mm. Weight is 2+ kg.

It would be disappointing if this would be EXACTLY the same lens. This lens was designed for FF and it would be unnecessarily bigger than it should. SO I hope that if it is based on the existing Sigma it might have been optically adapter to MFT.

Hope sources can soon confirm (or debunk) this rumor…