Newbies are struggling with the 17-40 and 24-105 lenses. I hope photographers can give me some advice! Thanks! ~

1.17-40 24-105 are not very good in imaging. There is a big gap from the first echelon. But the 17-40 is a very cost-effective full-frame wide angle (because the advantages of the 16-35 are not strong enough), while the 24-105 can only be said to be better in terms of focal length, but the aperture and image quality are not enough.

(The advantages I mentioned above are only for full-frame)

2. Let’s look at the APS-C model.

When the APS-C model is paired with 17-40, 27.2-64　F4. In terms of focal length, there is basically no wide angle. In terms of imaging, more generally, the purple edge dispersion is severe. In terms of aperture, it's still on the small side. What is the significance of this head? Internal focus? Appearance?

24-105 is equivalent to 38.4-168 F4. The focal length is not even 35, which is very convenient later. When it comes to imaging, the same principle is more general. When it comes to the aperture of F4 at the telephoto end, what is the use? Anti-shake? Appearance?

3. I think the 17-40 and 24-105 were originally designed for those who don’t have enough money but insist on going full frame. Firstly, it allows them to buy lenses, and secondly, by raising the price, they can earn more. You only have 70D, and then go to super wide? Why come and lie down in this muddy water?

4. Your purpose, online shop clothing flat shooting. The simplest method, 50 1.8, has better imaging than 1.4. Very good value for money. If you need details, add a 20 yuan macro adapter to get it straight away. For travel portraits and scenery, go directly to 15-85. Focal length 24-136, imaging and focal length are well balanced. If you have the money, consider the 17-55. The imaging is better than the 17-40, and so is the aperture.

5. If you still decide on 17-40 24-105, I can only say that what you are looking for is not the imaging and reality. Mainly the red circle L. If you choose 17-40 at both ends, it can be used as a similar focal length to 18-55, but it is not long enough. Equipped with 24-105, the wide angle is directly discarded. If I choose, I might consider the former.