Mongo has only just acquired a lovely used copy of this lens. Weight is an issue with the f2.8 version when travelling for holidays so he thought this might be the answer.
Mongo is yet to do some fine AF adjusting on the lens when the weather clears long enough for that to happen and also to take more test shots. For now, he thought he would take a quick shot in difficult circumstances to really test its abilities.
300mm f4 at effectively f16 i.e stopped down 2 stops and with X2 converter (20EIII), tripod, on AF tracking mode, ISO1600, shutter 1/100th, -0.7 EV, D800 set to 1.2 crop factor. The image is virtually uncropped in post processing and only some noise reduction and mild sharpening applied.
Mongo thinks it did alright in the circumstances and is not unhappy with it. Should be able to do better when Mongo gets to know all its little quirks
Below is the original RAW (NEF) file with nothing done to it but reduced in size for posting