Lens ?

[eyeguy 54]

pic a is is from my 18-300 set at 300. pic b is from my 55-300 set at 300. why so much difference? I was checking clarity on the 2 and saw the difference.

[Dbl]

I believe what you might be seeing here is "focus breathing". Say you shoot at 300mm on both lenses, when you actually focus the lens it moves its focal length slightly. Each lens has its own amount that it moves so that might be what you are seeing. For the most part this is both negligible and or not noticeable unless you do focus stacking with macro lenses.

[eyeguy 54]

interesting. I wonder if i use maunal focus it does the same. will check. thx!

[eyeguy 54]

hmmm, same thing. just another thing that makes me say, hmmmmmm. lol

[Dbl]

Well it will do the same thing on manual or auto focus. Focus is focus the only thing that changes is the method to accomplish that (assuming you are using the same focus point).

The point I was making in the first reply is that focal length changes when you actually focus. To check you normally use manual focus to take out any errors or in-accuracies in auto focus systems. But assuming both manual and auto focus on the same spot the error would be the same.

[eyeguy 54]

thx, I used the center spot focus on the same spot on the feeder. one lens is 4.5-5.6. and the other is 3.5-5.6. smoking turkey legs is easier to figure out.

[Dbl]

LOL, there you go. Its all really irrelevant, but it can make for interesting discussions.

[pulsar_nx]

Its probably due to the one being a 16x lens and the other being a 5x lens it is sure to struggle for focus accuracy.

[eyeguy 54]

focus is fine on both. I just thought when I maxed them at 300 zoom I would have the same pic. I was surprised that it was different. I sent nikon a note to see what they say.