18-55 vs. 18-70 lens different zoom?

[000destruct0]

I feel stupid for asking this and maybe I'm totally off base. I have a Nikkor 18-70mm lens with my D50 and I was amazed at how poorly it focuses at close distances. I attached a friend's Nikkor 18-55mm to my D50 and it gets remarkably closer with the same item in focus. My assumption is that 18mm settings on two lenses with the same body should produce focus at the same distance. Am I wrong to assume this?
What might be wrong with my 18-70mm lens then?

 

[DerekSalem]

Some lenses are better at macro focusing than others. The minimum focus distance on the second lens is just closer than the first. Every lens is different

 

[Dao]

When you look at the lens specification, take a look if they have something like "Closest Focus Distance" or "Minimum Focus Distance"

 

[Big Mike]

It's probably not on the lenses, but you can usually find it on the spec sheet (in the manual or on the manufacturer's website).

"macro' doesn't always have the same meaning when it comes to lenses. What most people consider to be true macro, is 1:1 reproduction. That means that the size of the object is the same size as it's image, as it appears at the film plane (sensor). For example (using a film camera), if you took a flat photo of a dime at 1:1, you could take the negative and lay the dime on the image and it would be the same size.

The problem is that many lens manufacturer's have started using "macro" as a sales gimmick. They stick that in the lens's name or on in the description, although it might only be capable of 1:4 reproduction. So you can't always be sure that a "macro" lens is truly capable of 1:1 reproduction.

AFAIK, all the Canon "Macro" lenses are capable of true Macro. It's usually some of the cheaper off-brand zoom lenses that you have to be weary of. I would assume Nikon lenses are similar to Canon in this.

 

[boomer]

The closest focusing distance for the two are as followed (copied from B&H):

18-70:
Minimum Focus Distance 15" (38 cm) Magnification 1:6.2

18-55:
Minimum Focus Distance 11" (0.28 m) Magnification 1:3.2