The focus issue may need some clarification. When Nikon talks about AF working, they are referring to the lens wide open and not your aperture. The Nikon system uses a wide open aperture for AF, then stops down when the shutter is depressed. That's why the DOF preview button is important. So when you are talking about AF working at f/8 on new camera bodies, it is looking at the lens and teleconverter wide open regardless of your aperture setting.

With a variable aperture lens like a 70-300 f/4.5-5.6 VR the f/5.6 aperture applies to the long end of the zoom - the place where you want more reach. So losing a full stop with a 1.4 teleconverter puts you at f/8 - an area where focus is only reliable with a few of the newest cameras. So even if you chose the Kenko teleconverter which will physically fit, you are at the limit of practical use.

The other thing to keep in mind is that not all AF sensors are the same. The center sensor is the one that produces f/8 AF. The adjoining cross type sensors produce AF at f/5.6. And the remainder AF at f/4. So if you want to try a teleconverter, you are probably going to want to use the center AF sensor. That is one reason why many of us use the back button (AF-On) to focus - so we can focus and recompose quickly. Also keep in mind focus reliability is not as good as you move away from the center sensor. You will get more images with missed focus and a wider range of AF error.

Many of the zoom lenses are not as sharp at the maximum zoom or long distances as they are in the sweet spot. But when you are using a teleconverter, you are often at maximum zoom - so of course the images are going to be softer. Add the normal image degradation of a teleconverter, and you end up with soft images unless your technique and conditions are optimal.

Finally - a teleconverter is going to reduce aperture and extend effective focal length. The longer focal length means you need a faster shutter speed to freeze any vibration or movement, and you need to offset the smaller aperture. So in practice you need enough light to add two stops to whatever you had without a teleconverter. This is true for all lenses - even those that accept teleconverters - and is part of why teleconverters are not used more often.

So I agree completely with the other posts. The teleconverter does not physically fit, AF is not as good or non-existant, you need more light, and image quality drops. You can overcome the physical fit with the Kenko Pro teleconverter, but the other factors remain.

I have the Kenko teleconverter and almost never use it. It is the most useless piece of equipment I own not because it is a bad teleconverter - its just the occasions when I have used it produce sharp images less than 10% of the time. That's too unreliable to be useful. I'm better off living with the constraints of the situation and gear, and working on techniques to get closer.

If you are on a tight budget with medium consumer lenses, the 70-300 ED (not VR) version is available used for around $175. It's a pretty good lens that has been around a long time. While not as good as the newest version, it is better than trying to turn a shorter zoom into something its not.

Here is the full frame of the above...

And, these cars are moving all over the place, so in a way it is like shooting a sports event where the direction of travel of the subject is not always known. I think for the price of USD $3000, the TC and 70-200 works very well.

OK, here is a crop from the 70-200mm f/2.8 VRII with the TC-20EIII. This is about 15% of the entire FX image. And it is shot at 1/400 sec, f/5.6 (wide open) with -0.7 ev. ISO 12,800.

The car was moving over 100mph and is about 600 feet from the camera.....

IMO, even with the 400mm f/2.8, at this distance one would not see a great difference, the only big factor is the sharpness would be higher as a result of lower ISO shooting at f/2.8 or using the TC-20EIII on the 400 would bring it up closer.

to specify Garteth post - most current bodies - from d200 can (in good light) focus with f8 or smaller (officially only d4, d800 and d600), though the focusing speed (AF tracking) is slower. what does it mean to TC users. basically, all f4 lenses can be used with TC20. all f2.8 lenses can be coupled with TC20 and TC14 - this option is also not supported by Nikon and requires TC trimming (I would say it's advance use of TC's).

wow!this is a great info Gareth...& i am totally agree with you dude.

Anytime I've considered buying a particular TC to use with a particular lens, I always send Nikon Tech an email and give them the model numbers and ask them what they think; They have always been pretty good about answering me.

Thanks all for replying.

After giving it much thought I don't think a TC would cut it with D800/soccer, lacrosse use because of multiple player density in a relatively small area (as opposed to a big car moving in almost predefined path with no arms, legs, goalnet, and sticks); unless I use manual focus, which I don't 80% of the time.

As suggested by many, I am leaning towards a fast fixed lense, but don't need to upgrade till spring next year.

In the meantime am hoping for nikon to upgrade their 80-400 or 300f4, in which case I will buy either one (most likely 300) and keep the 80-200 for indoors/night use.

El_Pickerel suggested a non vr used 300/2.8, this will work very well; but they (AF-S D versions) are still 3k, to afford that I may have to sell 80-200 (probably get ~$650 to $500) and be left without an indoor/night time lense. I have the 85/1.8g but that doesn't serve the purpose all the times.

Maybe my financial situation would change, and I can buy 300 vr, still have 5 months to save.

I wish I'd hung on a bit longer for a 300/2.8 (I'd really prefer a 400 if I had a choice). A mint used one (400) was offered to me a few weeks ago and I didn't have the cash available so I started to sell off all of my Pentax gear but someone bought it the day I called to buy.. The 300/4 is a nice lens but doesn't grab my imagination for some reason. I really like the 14E II though.. I'd never use a 2x on these lenses.. I did buy one but couldn't return it quick enough when it turned my 70-200 VR2 to mush.

Nikoner said:
Advise wanted on D800+fast tele+tc

1) I wonder how a 70-200 vr2 with a teleconverter fare for soccer?

this is not a good combination with the D800. The 70 -200 is a fabulous lens, the D800 a brilliant high resolution camera

The x 2 converter will magnify any defects in the 70-200
and with a D800 those defects will show
You will not be much better off than simply cropping
The answer is one of the expensive super teles
300 f 2.8 + 1.4 converter
200 -400 f4
400 f 2.8 + 1.4; 1.7 and x2 converters

http://nikonrumors.com/forum/topic.php?id=8053

Yes they are expensive, and sorry, if you want high, IQ you are going to pay for it

@ PaulR

Information has it that Leica built a one-off APO-Telyt-R 1:5.6/1600mm lens and it cost $2,064,500.

To see the photo http://nikonrumors.com/forum/topic.php?id=8053&page=3

I moved up to the Mk 111 converter quite a while ago.I now use it with a 300 2.8 =600 and a V1 2.7 crop factor = 1620. Needless to say this cannot be hand held but I shudder to think if Nikon made a lens this big what would it cost
When used with the V1 video mode , I am amazed at the quality, Ok I don't use this converter everyday but I would not be without it

@ bossa

No argument about the D800 having greater resolution characteristics....

So, if one wants good resolution, 300mm f/2.8, 400mm f/2.8, 500mm f/4 are the lenses of choice, used as suggested by El_Pickerel. And, the question for me is aways just how large does one want to go in the final print? I tend to be very pragmatic about all this.

For the money, I am still of the opinion the teleconverter is the best option.

msmoto said:
I have shot hundreds of race cars, some at high shutter speeds, some at slower shutter speeds. And, with the D90 and with the D4, I have no complaints with the 70-200mm f/2.8 VRII with either the TC-20EIII or TC-14EII. I wonder if the lens/
TC, camera body needs to be fine turned in cases where there is a problem. Now, shooting wide open with the TC...this may be where problems show up. I have not tested this out, but will be doing this in about three days shooting the World of Outlaws at Charlotte, north Carolina at night . I will use the 70-200 with TC 20EIII and try to remember to shoot some wide open.
But, the alternative to a 70-200 with teleconverter is a 200-400mm f/4.0 for nearly $7,000......or a couple of non-pro zooms to 300mm

Of course the 300mm f/2.8 with a TC-14EII would be a nice lens.

With due respect the OP is asking about use with a D800 and I doubt a D90 or D4 qualifies as an answer in this regard. The D800 will show up every fault in the optics if you zoom in to 100%. And why wouldn't you? You may as well buy a D4 or D90 if all you wanted was Lo-res. ;-P

Nikoner said:
Advise wanted on D800+fast tele+tc

I shoot sports indoors, outdoors, and at night under the lights.
Use a D800 as primary and D90 as backup.

I had bought the 80-200 2.8D as a stopgap measure till I can afford the 70-200 vr2, indoors I can get by with it, but for outdoors sports like soccer/lacrosse/baseball the tele end is limiting.

If you are shooting sports, I imagine the VR is not the greatest concern for you as you are stopping motion anyways. Maybe you can look at older pre-VR telephotos. The demand is much lower for these lenses - for example you could get an older 300mm f/2.8 lens for a steal.

I have shot hundreds of race cars, some at high shutter speeds, some at slower shutter speeds. And, with the D90 and with the D4, I have no complaints with the 70-200mm f/2.8 VRII with either the TC-20EIII or TC-14EII. I wonder if the lens/
TC, camera body needs to be fine turned in cases where there is a problem. Now, shooting wide open with the TC...this may be where problems show up. I have not tested this out, but will be doing this in about three days shooting the World of Outlaws at Charlotte, north Carolina at night . I will use the 70-200 with TC 20EIII and try to remember to shoot some wide open.
But, the alternative to a 70-200 with teleconverter is a 200-400mm f/4.0 for nearly $7,000......or a couple of non-pro zooms to 300mm

Of course the 300mm f/2.8 with a TC-14EII would be a nice lens.

My 70-200 VR2 was woefull with th e TC20 series 3 but great with the 14E II..as is my 300/4. The viewfinder is very dark with the converter and the 300/4 though. Keep in mind that a f/2.8 lens becomes a f/4 lens with a TC14 and 2 stops slower with the 20E III.

Advise wanted on D800+fast tele+tc

I shoot sports indoors, outdoors, and at night under the lights.
Use a D800 as primary and D90 as backup.

I had bought the 80-200 2.8D as a stopgap measure till I can afford the 70-200 vr2, indoors I can get by with it, but for outdoors sports like soccer/lacrosse/baseball the tele end is limiting.

I am thinking of trading it in for a fixed, fast lense.

I tried 300 af-s 2.8 vr2 it is magnificent indoors & out, and totally out of my reach at 6k.

300 f4 will not give desired shutter speed indoors and like 300/2.8 also be a bit long for inside use.

1) I wonder how a 70-200 vr2 with a teleconverter fare for soccer?

or

2) I wish there was something like a 200/2.8 vr3 @ ~ $2k in the pipes? (I cant afford the f2)

or

3) Keep the 80-200 and buy a 80-400 for outdoors day sports, when they upgrade it?

A very lengthy and informative article on this topic can be found on Lens Rentals site, written by in-house guru Roger. I can't put the link here because I can never remember whether they're a sponsor, so you'll have to Google it. Sevencrossing does a good job of summarizing the issue though.

I will warn against trying ones that aren't on the list...I would make certain they will work. You will scratch the rear element on your lens by say putting the 18-200 on a teleconverter.

So two factor...light loss as mentioned and space between the rear element. General rule...constant F2.8 to use any of them. Constant F4 is decent with 1.4 and 1.7, but too much loss at 2.0. I don't know of any variable aperture lenses that are compatible, but I haven't looked into it much.

Teleconverters reduce the aperture. A f2.8 lens with x 2 converter becomes f 5.6

The smaller the aperture the slower the auto focus

The auto focus does not work well below a certain aperture, so for example the x 2 only works well if the main lens is f2.8 or wider, this rules out all "consumer" zooms
leaving you with the 70-200 f 2.8

If you have the 200-400 f4 , Nikon, say auto focus will only work with x1.4 but people do use this lens with the x 2, although the focus may be sluggish

the latest Nikon D800 and D4 are ment to have better auto focus at smaller apertures

remember autofocus happens with the lens wide open ,

there needs to be enough space for it to fit for one thing. i.e. the back element is far enough forward in the lens for the tc to slot in behind it.

then there are issues of aperture for af, which nikon doesn't over commit itself to. they don't want people complaining when it doesn't af, they'll just say they never said it did. that doesn't necessarily mean it wont though.

What determines teleconverter - lens compatibility?

Looking at the "official" Nikon list, not that many lens are compatible. However, I keep seeing comments about various lens not on Nikon's list being used successfully with a TC.

Is Nikon's official list a marketing effort to keep people from using the TCs except with the most expensive lens, or is there something else going on here?

Intuitively at least, I would think that an IF lens would stand the most chance of compatibility, as nothing external moves...

Can someone please clarify?

Eric said:
@andyp - Liveview and its' associated AF system uses the data at the image sensor, so Liveview focusing (contrast detect) is very accurate, (but slow).

Hi, sorry I'm late to this party, as one who has never had the courage to play with the manual AF adjustment on my cameras, because the opportunity to screw it up seems all too real, and the expertise to do it correctly seems beyond me, the above comment got me thinking Eric. Why can the camera not use its contrast detect system to calibrate the phase detect AF on the camera? Am I missing something? It seems to me if that was possible, then you could attach any lens/tc combination to the camera, perfrom the calibration, and all of your equipment could be set up quickly. I'm sure if it was that simple the system would already exist, can someone explain to me why it's more complicated than that?

@sevencrossing - TCs work fine on the 200-400. Prior to the D4 & D800, AF could be occasionally iffy with anything except the TC 14. Here is the Nikon Teleconverter Compatibility Chart:
http://www.nikonusa.com/en_INC/IMG/Assets/Common-Assets/Images/Teleconverter-Compatibility/en_US_Comp_chart.html

This chart has not yet been updated and still reflects the f/5.6 capability of the old AF system. I believe that with the new f/8 AF capability of the D4 & D800, all of the TCs will autofocus with the lenses listed on this page.

I have and enjoy the 200-400, but it is not great at infinity. I keep it under 300 meters and its great. But, it is quite large and I rarely even try using it without a monopod.

The 300 f/2.8 is phenomenal and it's great with TCs. I love mine and you can't go wrong with it... except that it is difficult to explain to ones' significant other that you need to spend $5500 on a lens in order to be able to spend another $500 on a TC.

msmoto said:
While I have the 400 and use it without hesitation with the TC-20EIII, I might recommend to someone the 300mm f/2.8, and both the TC-14EII and the TC-20EIII. The 300 is a lens which one can hand hold, the 400 is a bit to heavy, for me at least.

Thanks the 400 is £6500 the 300 "ONLY" £4000