Nikon 50mm 1.8G - more like 55mm?

[Dmac60]

Compared to my other lenses (Tamron 17-50 and Nikon 18-105), my 50mm 1.8G seems to have an extra few mm compared to 50mm on the zooms - is this normal?

 

[redddraggon]

What sort of distance are you focusing at?

 

[Dmac60]

1.5m when I noticed.

 

[redddraggon]

1.5m when I noticed.

That might be why then, some lenses do something called "focal length breathing" at close range and appear to have a shorter focal length. It may be that both your zooms suffer from this while the prime doesn't as much.

Try focusing at infinity and you may see less of a difference.

 

[HoppyUK]

Edit: crossed post with James

Common. Though it'll be the other way around with the zooms understating, especially at closer distances.

Focal length only holds true at infinity focus. Some zooms are notorious for 'focus breathing' as it's euphemistically called, and most 70-200s are more like 150-160mm max when you get down to 3m or so.

 

[Dmac60]

Thanks for the explanation