nikon 18-200 vs 55-200mm focal length difference..why?

[subabu2002]

hi SP and friends,

i had oppertunity to use both lenses.. i tested both the lenses for checking if any focal length differences.. surprisingly i saw the differences at same focal length,same place,same camera.. for example,



@200mm

1.nikon 55-200mm vr lens



2.nikon 18-200mm vr lens










@70mm

1.nikon 55-200mm vr lens




2.nikon 18-200mm vr lens




which one is correct? why this differences with same company? is there any reason for this diffrences?

please help
suresh babu

[Ravish.Khare]

I have Canon EF-S 18-55 mm and Canon EF-S 55-250 mm.
Now only 55 mm is common. So I checked at 55 mm in both lenses and found a bit of difference. Logically, there shouldn't be a difference. Do the lens manufacturers need some more quality controls?

[gopall]

it is the difference of fixing lens element in single and in groups...besides, the manufacturing units exist at different places...some lenses are made in china and other in korea etc...there is no match of 100% with any company.
-time gap may also change in inner design of the same focal lengths, depending upon the feedback from the market/users.