Aperture and Long Lenses

[John Driscoll]

I just returned from the 2015 CES and got a chance to play with Nikon's new 300mm F/4 PF ED Vr.....

My personal experience, which is limited, is that anything above an F2.8 is less sharp.  This can certainly be my technique, but I would like to get some input.

I have rented a Nikon 200-400 F/4 for a couple of airshows, and didn't get anything spectacular.  However, the shots I took with my 70-200 F2.8, even with a TC, seemed sharper.

I will try a 300 F2.8 or 400 F2.8 prime for next attempt, but the size and price of this new lens has me very intrigued.

[Jay Beckman]

Canon's 200-400 is at least as sharp as my 500mm f/4L IS and it gives my 300mm f/2.8L IS a solid run as well.

[Anna M. Wood]

John,

What do you mean by not getting anything spectacular?  What were your expectations of what you would see with the lens?  Can you post an example image or two that shows the issue you feel the lens has?

I am assuming that you can adjust the micro-focus of the lens / body combination on your Nikon, like one can do with Canon bodies. 

My 300mm f2.8 prime with 2x extender had a soft focus until I did a micro-adjustment of that combo with my 7D2 (about 7 ticks).  Made a world of difference for image quality for that combination.

[John Driscoll]

Perhaps that is what I get for renting 2 different lenses from 2 different places.

The first Nikon 200-400 f4 I used on a DX body (Nikon D5200), under cloudy skies at the St. George, UT show.  The second I used for the first time on my New FX (Nikon D750) on the second and third day of the Miramar show.  I used the Nikon 70-200 F2.8 the first day on that body and all of my keepers seemed to be from that day.  Days 2 and 3 were very soft under the same lighting and shooting techniques.

The D750 is capable of micro focus adjustment, but wasn't within my capabilities at the time.

Certainly not trying to blame the lens, just getting the kind of feedback that I need to make better decisions going forward.

[Jay Beckman]

The max aperture of a lens is usually a moot point in our world because of the slow shutter speeds we tend to work with in daylight which yield such small apertures.

More often than not, I'm more concerned with diffraction at f/13 and smaller and will sometimes drop in some ND in an effort to push my aperture back closer to the sweet spot (usually around two stops below wide open.)

[John Driscoll]

Picked up this little contraption the other day.  Looks like -3 is the magic setting for my 70-200 f2.8.

I'm certain this will help when I pick up random rentals.


upload a picture

[Jay Beckman]

Does that -3 hold up through the entire zoom range?

[John Driscoll]

Seems to Jay.  Pretty accurate at both 70 and 200.  Did not try with TC.