Please help me choose two SLR purchase schemes.

Hello, let's settle the choice between Sigma 17-70 and Canon 18- 135 first.

First, determine the positioning of the two lenses. Sigma 17-70 is a mid-range lens, while Canon 18- 135 is an entry-level lens with this kit. The positions of the two lenses are different. But Sigma is the vice factory and Canon is the original factory.

I won't talk about the original model.

Sigma 17-70 won the grand prize in the 22nd CAPA lens selection in Japan in 2006. The comprehensive reflection is not bad, but it is said that there is some light loss at the four corners of the maximum aperture at the end of 17, and sometimes the film is slightly yellow. Generally speaking, this lens belongs to the mid-range economical lens, and the imaging effect of the lens is excellent.

Compared with Canon 18- 135, large aperture is an advantage. The advantages in imaging are not so obvious. At least there is no distance.

So it depends on the subject you shoot. If you are often in a place with poor light and it is easy to focus, then choose the lens of 17-70. But the aperture of 17-70 is not large! Longteng A 16(B005) can also be referenced at the same time, and the imaging is half a catty. The aperture is larger, and the focal length is enough.

If it's just for normal use, it's for sightseeing, recording and taking pictures by the way. It is suggested to directly select 18- 135 and 50 1.8. Changing it to 17-70 is of little significance!