Lens hood always necessary?

I'm setting out on a trip on foot tomorrow to hopefully get some shots of the European bison that were reintroduced to The Netherlands a few years ago. It will be an overcast day, which led me to the question if I could leave the rather bulky lens hood of my Nikkor 80-400 at home.

In my understanding, a lens hood is mainly used to reduce the chances of flares from bright sunlight, of which there is no chance on an overcast day. However, I read somewhere that the hood also protects from diffuse stray/indirect light that may compromise IQ, which would mean that I have to bring the hood anyway.

Is this true and do you have any experience that IQ is indeed compromised? I'm not a faithful user of lens hoods, but have never noticed any obvious IQ loss apart from flares from bright sunlight.

Lens hood do three things they protect the front element help reduce flare and add contrast I always use them and really would not consider the hood for a 80-400 bulky.

Hi Jerry:

I used my Canon 400 DO (with and without 1.4TC) without a lens hood for most of the 3 years I owned it and never had an issue. If you photograph much more than birds, you probably want to consider using and taking the hood.

Hi all, I am not a technical expert in any way however, I never ever use any lens without the hood - both for bird photography and for my professional photography work. The reason for that is simple: lens hood is an integral part of the lens and it is there for a reason. I am sure everyone including the manufacturers would have loved to sell the lens without it but they all keep it. For me it's a good enough justification to use it as recommended.