Which is correct?

@MahaB82A 

This is an imitation of a classic real-life photographic situation: Your shutter speed isn't high enough to completely freeze all motion.

So you have two choices:

• you can pan the camera to freeze the skater - this is what sports photographers generally do.
• you can keep the camera still and let the skater blur past - this is what an architectural photographer would do in this case.

In other words, this is a choice, depending on what you want. You need to decide that for yourself.

Both are different valid ways of showing a subject in motion.

Both can be created in camera depending on the decisions you make when you take the picture.

The one that is correct depends on the photographer’s creative intention for the image.

An image like the left one can be created in camera by panning the camera to match the subject as you press the shutter button, while using a slow shutter speed. This would make the subject sharp while creating motion blur in the background.

An image like the right one can be created in camera by holding the camera still as the subject goes by at high speed, while using a slow shutter speed. This would create motion blur in the subject while the background is sharp.

usually In videos  we can tell how fast something is moving by how blurry it looks. But in Still photos, showing movement is a bit different as we need to keep the subject clear while still showing motion.

in digital SLR cameras, we often use shutter priority and sometimes speedlights to avoid a dark image when freezing the motion.

In the first photo, we see what most people expect: the subject is sharp and in focus, and the background (the building) is blurry ( Our brains are used to seeing this kind of effect usually in graphic designs )

However I prefer the second photo as it is a bit of " creative twist" : 

We can see the subject’s speed clearly, even without the background as a reference.

Hi,
I advise you to use the image where the effect was applied to the building. 🙂