planepics Loc: St. Louis burbs, but originally Chicago burbs

I was looking at possible rentals for the summer and one of the FAQ had to do with AF-D compatibility with a particular body. In a search I tried to find out what it meant and I just want to be sure I understood it...it has to do with the camera automatically adjusting the power of a flash unit?

rmalarz Loc: Tempe, Arizona

http://photo.net/nikon-camera-forum/00LuUJ

--Bob

MT Shooter Loc: Montana

The "D" is for Distance, in simple terms it allows the camera to TTL the flash while the amount of light is determined partly based on the Distance that the lens is focused at.

Entry level Nikon DSLR cameras will not focus AF-D lenses as those cameras require the lens to have a focusing motor inside the lens. AF-D lenses all have a mechanical screw-drive focus system that relies on a focus drive motor inside the camera body.

RWR Loc: La Mesa, CA

Its not just for flash. The focus data also helps determine which matrix meter segment is most relevant for the exposure.

planepics Loc: St. Louis burbs, but originally Chicago burbs

Thanks for the answers. I'm contemplating the purchase of an a99ii and wanted to try one out at an aviation convention I frequent (never used a ff) but noticed that an a99 is quite a bit cheaper, although less well equipped. At least it would give me an idea of the IQ vs my a77. I've had some luck with pics at the same event with the a77 (2 winners on the net and one in a book for charity) so I figure with a better camera, who knows what I can do. Besides "plane pics" I also like trying macro, although I'm not very good at it yet. One thing I like about the a77 is the 12 fps - ideal when the Blue Angels are performing...If I DID rent an a99, I'd probably take the a77 for the reach with the 70-300.

a6k Loc: Detroit & Sanibel

I have arranged a rental of a camera and 2 lenses for the week of the 30th. My reason appears to be the same - try it out before spending enough to buy a good used car.
I found that dealing with https://www.lensrentals.com has been a very positive experience. They have experts and have helped me with compatibility issues. I can't comment on the actual rental yet, but I'm impressed with their overall approach and telephone service. If I had a question like that I would feel free to ask them. Just my $.02.

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

The D stands for the fact that on Nikon lenses the lens communicates the Distance you are from the subject to the flash unit, it is one of several systems the camera uses to determine the amount of flash output to correctly expose your shot.

amfoto1 Loc: San Jose, Calif. USA

"AF-D" is a Nikon-specific term for one of their many different types of lenses, and it really only matters to Nikon users.

If you are using a Nikon, they have used two main types of autofocus drive over the years: an in-camera motor and an in-lens motor.

As previously stated, AF-D Nikkors do not have a motor in the lens. This is no problem for users of the more advanced Nikon cameras, such as the D500 and D7000-series models, because those have the focus drive motor built into the camera body and are capable of focusing both lenses without and lenses with a built-in motor.

"AF-S" and now "AF-P" lenses are the Nikkors with a motor built-in. If they want their camera to be able to autofocus, D3000-series and D5000-series Nikon camera users need to buy this type of lens and avoid the AF-D.

AF-D lenses can be used on those more entry-level camera models, but will be manual focus only. There also might be some light metering limitations depending upon which type of Nikkor is used on which camera.

Here's a reasonably complete and concise chart of Nikon camera/Nikkor lens compatibility and limitations:

https://www.nikonians.org/reviews/nikon-slr-camera-and-lens-compatibility

That chart does not yet include the AF-P lenses recently introduced. AFAIK, they're similar to AF-S.

bdk Loc: Sanibel Fl.

Ive posted this before its helpful understanding some of the letters on a lens
http://improvephotography.com/888/finally-a-simple-guide-to-lens-acronyms/