Focus at infinity

[biggerry]

I have a 100-300mm old school lens that I use quite often, I learnt early on that with the focus barrel rotated all the way to the infinity stop the images of things in the horizon, and even the moon, are not terribly sharp, however, backing the focus off the stop just a fraction really improved the sharpness and i guess that point is the real focus for infinity.

Has anyone else experienced this with other nikkor lens? It is not of real concern for me, but I am curious if anyone else has had the same issue.

[Big Red]

AF lenses are more likely to do that as they need room to "go past" the focus point so they can then turn back the other way.
i have one that is exactly on the mark and in certain weather conditions it gets stuck there as it can't turn back because it is still trying to go forward.

[aim54x]

A lot of my lenses focus past infinite....but I have never noticed them AF-ing past infinite nor have i noticed them being not as sharp as infinite.

[Matt. K]

Many zoom lenses focus beyond infinity because this position changes as the focal length changes. (I'm pretty sure I've got this right!)

[ATJ]

I think that is true of most lenses. It is just more noticeable with longer lenses as the magnification is greater and depth of field is less.

[Photopotamus]

Seems to me I recall reading somewhere that the tolerances beyond infinity were to allow for "environmental changes" (ie: temp, humidity, etc..), that would cause minor variations (expansion/contraction) in the lens construction.

[Mr Darcy]

Dare I admit that I have been caught by this on more than one occasion. Usually on a night shoot. "Arr it' a long way away... I'll just turn the focus ring all the way...She'll be right"

[Willy wombat]

Its a trap - I learnt the hard way that screwed out all the way is not infinity, (its just back a bit)

[biggerry]

AF lenses are more likely to do that as they need room to "go past" the focus point s

yeah, all my AF lens do this, however my 105mm f2.5 stops smack on the infinty point and seems to be in focus, quite handy when you just want to bang it out to infinty without worrying about the horizon or whatever not being in focus.

Dare I admit that I have been caught by this on more than one occasion.

yep, been done on this as well, however only on the AF units when doing manual focus.

When I get a spare 5 minutes i will take some sample shots for interests sake...