85mm f/1.4 AF-D with PN-11 extension tube

[narayan]

Is it safe to use the 85mm f/1.4 AF-D with the PN-11 extension tube? What is the maximum magnification, working

distance, effective aperture, and effective focal length of this combination? I'll also appreciate any comments

on the image quality of this setup for macro work. Thanks.

[bjørn rørslett]

It's perfectly safe. Both items have matching "F" mounts.

 

The PN-11 adds 52.5 mm of extension so you won't quite to 1.1. Focal length is 85mm. I'd guess effective aperture drops to near f/2.8 if the pupil factor is included but haven't computed the exact value (why, the in-camera metering takes care of that anyway).

[dennis_d._hardenburger]

The only thing with Nikon extension tubes is no auto focus, which most people prefer to focus manually any way with

macro work. The metering with work fine.

[narayan]

Thanks, Bjorn and Dennis. I appreciate your comments. So the extension would cost about 2 stops of light, leading to an effective aperture of f/2.8. Then the viewfinder should be bright enough to focus. Now does this imply that my effective focal length is doubled to about 170mm (smaller f-stop for the same physical aperture size)? Also, does the IF design imply any additional changes in focal length? I hope the working distance and image quality are acceptable. By the way, I am using a D300.

[bjørn rørslett]

¨The focal length remains 85mm. An extension tube isn't a teleconverter. The working distance at nearest focus is

approx. 13 cm and magnification is about 1:1.3- The effective aperture is between f/2 and f/2.8.Don't expect

miracles in terms of sharpness unless you stop down a bit, but flatness of field seems to be quite good for fast

lens.

[Peter_in_PA]

Can you afford to just get a micro 105mm lens? Probably be better. What will you shoot actually anyway?

[bjørn rørslett]

If you already own a PN-11, the Micro-Nikkor 105/4 is the obvious companion for it. You'll get excellent close-up quality, nice field handling, and a huge free working distance. The 105/2.8 AIS also mates well with PN-11, but there are caveats due to the built-in CRC feature of that lens (same applies to the 105 F Micro).