Advise please - Canon EF 24-105mm f/4 L IS USM Lens

Hi all, I,m thinking of buying the above as a replacement for my current walkabout lens.
(Canon EF-S 17-85mm f/4-5.6 IS USM). My question is would this work ok with my 50D ?

Yes it will and it is a fine lens. But, most people here, me included think one of the 17-5x zooms better on your body: Tamron 17-50/2.8 etc.

Yes, the 24-105 will work fine on your 50D
You might however, find that 24mm might not be wide enough for your shooting style particularly when wide images are needed, have in mind that 24mm on a crop sensor behaves as 39mm.
Many pair the 24-105 with a ultra wide like a 10-20mm

It would be a solid upgrade from the 17-85 for sure, but as the others have said, 24 may not be suitable as your widest focal length on APS-C. Go back and look at the photos you have taken over time with the 17-85. How many of them were wider than 24mm? That will tell you a lot.

I upgraded from a 17-85 on my 40D -- with my shooting style I never have missed the wide end -- it is an improvement in almost every way over the 17-85 and I actually appreciated the extra reach and constant f4.

A good upgrade. Go for it!

The 24-105 is my general purpose/walkabout lens for my 50D. It is also the widest lens I own. There has never been one time it was not wide enough. I love the 24-105 with my 50D!

The 24mm focal length on a 1.6 crop camera gives a wider field of view than a 50 mm lens on a 35mm SLR film camera. A 50mm lens was the standard kit lens that came with 35mm SLR cameras for decades. I didn't know there was anything else available. We used foot zooming long before it was a popular phrase.

I would advise a Canon EF-S 17-55 f2.8 IS (or Tamron 17-50 f2.8)
Had them both on my 40D and ideal lenses!

I had the 24-105 also but on Fullframe, where 24mm = 24mm but sold it due to f4 not so fast, bokeh less nice than f2.8 and a lot of vignetting on 24+105mm. Now I have the 28-70 f2.8L on fullframe.

I never take f4 lenses again, I do a lot of portraits (also on my walkaround lens) and I like f2.8 fastness, also when in less ideal light conditions.

Ideal is combining with the 55-250 IS (or 70-200 f2.8) for more reach.
The more reach you want in 1 lens, you know it's compromising in fastness, bokeh and IQ.

That's a classic discussion, but fact is for most people the 24-105 is a good allround lens for fullframe in brighter days. Some people use it on crop, you can but it's not ideal due to the 24mm x 1.6 is no real wide-angle, so less allround if suddenly something more needs to be on the picture.

This one complains here allready, has to change lenses too fast with his 10-20
https://photography-on-the.net/forum/showthre​ad.php?t=999549

24-105 is fine, I use it on a 40D, definitely a step up from 17-85.
I use it alongside my 17-55 (mostly outdooors), the extra reach is great for portraits and the 24mm on the wide end does not hurt if you can move freely or if there is room enough.