No zooming Hello The lens do not response when I am turning the zoom ring?!

In either mode, you're zooming by turning the zoom ring on the lens? In live view mode, if you zoom in by pressing the magnifying glass button, all you're doing is zooming the display, not the image itself.

The zoom button merely zooms in on the display. It magnifies a portion of the picture so you can get a better look at what you're about to photograph. LiveView or otherwise, if you want to zoom, you have use the zoom ring on your lens (assuming you're using a zoom lens in the first place, of course).

Some of the Rokinon (and other ) zoom lenses could only go into MACRO at certain focal lengths- the lens you have "zooms" from 80 to 200 focal length,but is that done by "sliding" a ring forward and back on the lens, or by twisting a different ring that the one that focuses?

Yes. It's a push pull zoom action.

One touch zooms as used on 35mm film SLRs used to have the same mechanism, the zoom ring twisted as well to achieve focus but now that most lenses are autofocus that's unnecessary. So you have a lens which just retains the push-pull, a far more natural action in my opinion and usually faster than a rotating zoom. Once you get used to it I think that you'll prefer it.

By contrast, most modern zooms have what was considered in 35mm terms to be an old-fashioned twin touch zoom: one ring was turned to zoom the lens and another was turned to focus it. This sometimes meant that after zooming you had to refocus; your push pull zoom will likely have a more technically demanding constant focus zoom action, there will be an additional manual focus control as well, but it's very much a minor secondary control used only when your AF has broken or is switched off.

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HI I need to no what fit the lens is

1) What camera body are you using?

2) I do not understand your assertion that it automatically zoomed in. Zooming is a manual function. The automatic functions of your lens pertain only to focusing on of the subject so that your picture is sharp and ensuring that the correct amount of light is admitted so that you have a correct exposure.

3) Are you sure you were turning the zoom ring and not the f-stop ring? The zoom ring is labeled 200 on one end of the scale and 55 on the other. It is also the widest ring on the lens barrel. When you rotate it, the physical length of the lens will lengthen as you rotate it clockwise (viewed from behind the camera) and shorten as you rotate it counter-clockwise.

4) For reference, at 200mm the angle of view on your lens should be 10 degrees and at 55mm about 40 degrees.

Yes, this happens even when the lens is brand new. Some other lenses have a Zoom lock to prevent it. What I did was to slip a flat rubber band around the black area just behind the zoom ring, the area where there is s white mark or line, with the band ring just touching the zoom ring. The rubber band should be fairly tight, but not too tight. When the zoom ring revolves, the rubber band touching it gives it just enough friction to prevent it from turning. You can adjust it to give as much friction as you want. Hope this helps. Jay

Slide a piece of paper partway under the ring (make sure you leave enough hanging out so you can remove it later) and see if that tightens the action some.

Another low-tech approach is to push the ring to expose the inner barrel, then attack one or more pieces of Scotch tape or masking tape.

Are you sure it's the zoom ring that's stuck, and not the focus ring? The focus ring doesn't move when the camera is in autofocus.
If it's indeed the zoom ring that's stuck, you can spend more money than the lens is worth in repairs, or buy a replacement (circa 35 dollars on ebay) for dreadfully cheap. Good luck.

The following blog outlines some repair options for a lens error:

http://camerarepair.blogspot.com/2007/12/fixing-lens-error-on-digital-camera.html