17-40F4 or 24-105F4IS for London

I originally posted this on the picture forum, but thought this would be a better spot.

The last time I was in London, I used a 28-200 Tamron Adaptall zoom on my Minolta film camera. It has been many years. I was not happy with the results. I do recall a few times when 28 was not wide enough. On full frame, which lens would you recommend for a trip to London and why? I am undecided between the 17-40 and the 24-105. I will bring a fast prime for indoors photos. I am mainly interrested in the architecture and street scenes for London and touristy outlying areas, like Bath, etc. I am also undecided about the fast prime to take. I am leaning towards the 35F2IS, but considering the Canon 50F1.4. I wouldn't want to carry more than 2 lenses, and weight is a consideration. Please, no recommendations wanted for a 70-200 or a telephoto. I am tempted by the 17-40, especially because it is more compact and lighter than the 24-105L. Do you really like having the wider focal lengths of a superwide in a city like London? Do you think I will miss the longer focal lengths and IS on the 24-105L?
I am usually a prime shooter, unless I am travelling.

The ultrawide of the 17-40 will open new worlds to you, but keep in mind that once you get past the 24 that distortion starts being a big factor. Going wide can be lessmstisfying when your images are full of bent building and keystoned towers. Some of that can be corrected in post, others not so much. I'm not arguing against the ultrawide, just wanting you to understand that width comes with a price, especially in an urban setting with lots of straight lines.

I would choose the 17-40 as it is a lot lighter than the 24-105. There's gonna be some shots in the city where the extra 7mm of play will benefit you such as shooting a building or bridge from a close distance. Of course you can always move back and zoom in with the 17-40 in order to minimize distortion.

If I'm unsure of which lens to bring, I would just bring the wider of the 2 just in case. So I would also recommend the 35 vs the 50mm. More angle of view. It might make your portraits unpleasant up close, but I'd rather deal with a slightly distorted face than not being able to catch a shot indoors bc not enough space.

I would have to agree with this particularly as the OP says weight is a consideration.
Neither of the lenses have IS but assuming an FF camera then that should not be a problem.
The one thing I would look at is some form of simple support for dusk/night shots a monopod , trekking pole with a camera screw or a simple bean bag.
Whatever you choose have fun and get some great pics

The 17-40 is sharp and it is fun on full frame, but it sure seems to distort faces if they are too close to the side of the frame.
Is my copy the only one that does this? It seems easy to get perspective distortion with this lens.

Perspective distortion is the result of your working distance, not the lens. But they are tied together because you coundnt work that close with a telephoto lens and frame the same. But portraits are better with a longer lens from further away.

You don't say what your experience with UWA is so I'm going to say that either will do an excellent job but if you are unaccustomed to using a UWA lens and don't have time to become skilled with it before your trip you are better to stick with the 24-105. UWA is something that takes time and experimentation to get good results with. In the case you are using a 2nd body you could add the 17-40. A cheaper and ultra fun alternative would be the Samyang/Rokinon 14 2.8.

The UW works fine for photos of people at 35-40. Things get very iffy when you are at 17-20. The 17-40 is a nice lens, with good color and contrast. I can easily see it doing very interesting things with photos of large spaces, but you do have to pay attention to what you are doing with the lens. I have used UWA more on a crop, but not a whole lot.
I wish the lens had IS, but then it would be much more expensive, and a 16-35.

When I went to London, I used my 10-22 on a crop sensor (so pretty much the same focal range as the 17-40 on FF). I used that lens almost exclusively and along with a 50mm prime, all my needs were covered. And like what you're planning, most of my shots were of buildings and architecture. That said, I agree with the above comment that you do need to get used to ultra wide shooting so you don't end up with crazy perspectives and distortions.

17-40 & 50 1.4 are a perfect combo i'd bring. Throw a 85 1.8 in too just in case you want extra reach with carrying a lot of weight and waste a lot of room.

I found my 17-40 to be just perfect for London, especially for scenes around the Thames. So that's what I will bring on my trip next week!
I am also bringing a telephoto (for panoramas) and a 30mm F1.4 for low light indoor pictures. Out of your 35 and the 50, I'd lean towards the 35 because it's a bit more useful indoors.