wdross Loc: Castle Rock, Colorado

As some have said, the Olympus 12-100 f4 with the Panasonic 100-400 is the best travel system for 4/3rds. I have heard of the slight softness at the 400 but not about repair issues. I have thought about this combination, but I have decided to go a different route. For me, I have decided to go with the Olympus 12-100 f4 and the 300mm f4 with the 1.4X teleconverter (I have an E-M1 mrII). One of the other considerations / possibilities would be the Panasonic 200 f2.8 with the matched 1.4X teleconverter. Yes, either setup would not be as versatile as the 100-400, but each lense choice would provide two focal lengths without much loss of sharpness. And I believe either lense / teleconverter combo would be lighter and slighty smaller than the 100-400 zoom. From the sounds of it, should you go with the 100-400, a good replacement insurance policy might be necessary to go with it.

RJM Loc: Cardiff, S Wales, UK

I have the 100-400 and I find it sharp to 400mm....so that’s 800mm optical reach! On the Panasonic the quality is very good with x2 digital zoom giving you 1600mm. X4 digital and you can easily see noise but it is 3200mm in full frame equivalent reach!

I used it on my G80 for bird photography. Focus often hits the branch instead of the bird and it’ll hunt to get correct focus. Same problem on G9. I tried different settings with no noticeable improvement.

I also have the Oly 75-300mk2. The lens is much lighter and a quarter the cost of the Pan 100-400. Unless you need the extra reach this is the better option. It’s a very good capable lens and better value.

To get 800mm optical on an APS-C or full frame system you talking thousands of pounds or dollars. As far as I know there’s nothing better for the reach snd the money than the Pan 100-400. It’s not perfect but it’s very very good quality image wise.

Others have mentioned it can be fragile mounted on some cameras. I remove it when not in use and it’s being carried.

HardwareGuy

Before making blanket statements like this, do have a read at this site, and it will help to dispel some of this misinformation:
http://naturalexposures.com/question-from-christopher-sawtell/

gordone Loc: Red Deer AB Canada

That is nice they go through the explanation of how they senscthe lens back to Japan and refurbish then. The kicker is the refurbished lens is $1400 and a new one is $1600 so who would buy a used lens for $200 less. So the point it this this a disposable lens

burkphoto Loc: High Point, NC

For those who own two professional level Lumix bodies (G85, G9, GH4, GH5, GH5s) and four of the qualifying lenses*, Panasonic offers a professional support organization service similar to NPS and CPS. It's $199/year in the US. For those doing serious video work, weddings, events, etc., it may make sense.

https://lumix-pro.us

For the rest of us, Panasonic has a way to go to ensure reasonable repair and support opportunities.

*Lumix-Pro QUALIFYING LENSES:

12-35mm f/2.8
12-35mm f/2.8 II
14-42mm f/3.5-5.6 Power Zoom
35-100mm f/2.8
35-100mm f/2.8 II
45-175mm f/3.5-5.6 Power Zoom
Leica 100-400mm f/4-6.3 - Vario-Elmar
Leica 12-60mm f/2.8-4 Vario-Elmarit
Leica 12mm f/1.4 Summilux
Leica 15mm f/1.7 Summilux
Leica 25mm f/1.4 Summilux
Leica 200mm f/2.8 Elmarit
Leica 42.5mm f/1.2 Nocticron
Leica 45mm F/2.8 Macro-Elmar
Leica 50-200mm f/2.8-4 Vario-Elmarit
Leica 8-18mm f/2.8-4 Vario-Elmarit

(In other words, these are the optics Panasonic considers pro-grade lenses.)

suntouched Loc: Sierra Vista AZ

While you are not addressing me, from my perspective (and a prior owner) it certainly feels like a disposable lens although I haven't heard it called that before. When a lens of this caliber and cost fails due to a mechanical defect, (not mistreatment) it feels very disposable when it can't be fixed.

HardwareGuy

I meant zero disrespect to anyone. It was just an interesting piece of information to add to the conversation when one poster was writing off the whole compay due to this lens.