Question400 f/4.5 GM or one of the 100-400s for football from the touchline?

My son moved up to 11-a-side this season, so the pitch is bigger and my 70-200 is now too short for anything past halfway. I shoot standing on the touchline, usually without a monopod, two halves of about 35 minutes. One body, the A7 V.

Options I am looking at:

The new 400 f/4.5 GM. £2,399, 994g. Light for a 400, but a prime with one body means anything that comes close to me is lost.

The new 100-400 f/4.5 GM. Constant f/4.5 and internal zoom, but 1,840g and much more money ($4,299 in the US, UK price I have seen varies).

The old 100-400 f/4.5-5.6 GM used. Cheapest, about 1.4kg, a bit slower at the long end.

With one body the zoom makes more sense, I know. But the weight over a full match hand-held matters to me. Has anyone used the new 100-400 hand-held for a whole match? Happy to answer questions.

I shoot my nephew's rugby with a used A7 IV and the 70-200 f/4, and I have exactly the same problem past halfway. I don't have an answer, I'm afraid, but I'll be following this. Thank you for laying the options out so clearly.

When I do youth sports for clients I use a zoom every time, because you can't predict where play goes and a prime on one body means missed shots. The 1.8kg is real, but a monopod fixes most of that. If this is your kid and you want keepers, it's the zoom. If what you actually want is the lightest bag, it's the 400.

dmitri_k said:

the weight over a full match hand-held matters to me

Then it's the old 100-400 used, and spend the difference on a monopod and a decent coat. You're shooting under-13s, not the Champions League... I know, I know, your money. Just saying.

cdalton_photo said:

a prime on one body means missed shots

This is my worry too. I rented a 400 prime years ago on a different system and missed nearly everything inside 20 metres. Monopod is a fair point. I own one, I just never take it.

@tomthurlow the used one is the sensible answer, I know. Not sure I want sensible.

FWIW... 1.8kg isn't heavy, it's a workout. I haul the 180-600 around the desert for hours at a time and that's over 2kg. A decent strap that goes across the body, not round the neck, and you'll forget about it by the second half. IMHO the zoom. Be kind to your son's highlight reel.

• Walt

Rented the new 100-400 for Saturday. Will see how my arms feel by the final whistle.