I am new to DSLR photography, and using using a Canon 1300D and Tamron 18-200. While using 200mm and trying to take a picture at 5 second or longer shutter speeds, I am developing camera shake and the McLean pictures ... even though I am using a tripod.
With the same settings while I use the 55-250 canon lens, I am getting crisp pictures. Is my Tamron lens faulty? Under 5sec shutter speed I am getting crisp images.
Sample images would be awesome - as there's a few questions here that might help you:
How can I prevent blurred images when using a tripod?
My own hunch is what WayneF commented: you're probably getting a bit of wobble from pressing the shutter release button. If this is actually the case, you've got options!
This answer, however, is highly speculative - and I'd really like to update it with something more relevant to you. So, please edit your question and add some samples to it! Thanks!
Although you do not state whether you are using optical image stabilization, I suspect optical image stabilization is responding to phantom movements because you have problems with exposures > 5 sec, but not with exposures < 5 sec. (You state: "Under 5sec shutter speed I am getting crisp images.") If this is the case, turn off image stabilization while using a tripod.
Image stabilization is the only lens function that actively alters the image during exposure. Aperture and focus remain constant during exposure. Although zoom is not intended to change during exposure, zoom creep is possible.
Other possibilities include:
Spurious movements of the tripod. Use a sturdier tripod or hang sandbags.
Movement of the camera caused by pressing the shutter button or mirror slap. However, this is unlikely in your situation because such movements would not take > 5 sec to affect the image. They would also be expected to affect images taken with both of your lenses.
See also (the same links Hueco lists):
