Camera/Lens question

It'll quarter the amount of light entering the camera body, so that'll be a bad thing, and quite probably the autofocus won't work at all, which is usually a really bad thing. Also, the image quality will be worse. Try one out in a friendly shop and see what you think. 

Tony

What are you trying to shoot?

The Nikon teleconvertors will not work at all with that lens, and third party teleconvertors will work badly. You will lose autofocus most likely and image quality will suffer as well.

Nikon teleconvertors really work much better with fast primes (like the 200/2 and 300/2.8) and the venerable 70-200/2.8. lens. I use a 1.4x with the latter.

Your best bet might be to look for a used Nikon 80-400mm f/4.5-5.6D VR, although it won't work so well for sports and low light photography.

All good advice. I have Nikon 2X teleconverter that I will use from time to time, usually with my f2.8 400mm lens. The teleconverter does lessen the sharpness and brings in some CA, But for distant subjects, with my 12MP D300, the teleconverter seems to have a quality benefit compared to cropping the smaller image you'd get without it. So it is the lesser of 2 evils. With the f2.8 lens, autofocus isn't an issue at all. The viewfinder is still bright. If I had a camera with a higher MP count (especially the D800), the difference would be slight, and may even favour using the prime lens and just cropping the image.

This was shot with the prime (and heavily cropped). Click through to Filckr to see full-sized.

DSC_4910 by winkyintheuk, on Flickr

I mostly shoot birds, boats and kite boarders at the moment. I met a pro photographer yesterday who had an expensive Canon rig with an enormous 70-200mm lens and a tele extender which she swore by and she specialises in shooting kite boarders all around the world - I had a look and I was amazed how much closer to the action she could get. I was hoping I could get the same type of set up without spending a fortune. 

I use Canon,  but same applies

I have a x2 that I have used with limited success.  I am a birder & LBJ's need a big lens & then some.  So a x2 seemed like a good idea.

I have since given up with it on my 70-200 f2.8 as I got better results & with all the AF & IS working properly with a straight 100-400 f4.5-5.6L & within sensible limits & cropping that seems a better solution. 

It works well on my short primes,  but in truth I rarely use it.

She had a lens that will work with a teleconvertor. You don't.

Her Canon 70-200 is probably the the red-ring 2.8, maybe an IS. That, like my Nikkor AF-S 70-200/2.8 VR, is designed to work with a teleconvertor, but it is a $2K lens.

I shoot motorsports and would love a 400mm lens, but the price of entry is stratospheric ($7K). If I want such a lens to shoot with at a race, I rent one, or borrow from a friend. 

RT,

I have no idea what she had - maybe you can tell from this cropped photo. Thanks for the information. I may have been tempted to take a punt at something on the internet so I am glad I asked for some advice. So a tele extender is out of the question and a 400mm lens looks expensive so I rather like your idea of a used Nikon 80-400mm f/4.5-5.6D VR. In what way might it not work so well for sports and any idea of price? Thanks for the advice. 

Forgive me if I am wrong. I am a mere amateur and terrible at calculating, but.....

I think the main problem here is going to be the aperture. It's ok to use a tele-converter with a (maximum) f.2.8 lens because a quartering of the light would change that to f.5.6, still ok for relatively fast speeds.

But, an (maximum) f.4 lens would change to f.8, meaning that speeds would be slower and it would be difficult to 'freeze' moving objects - probably one of the main reasons for buying a long telephoto.

Perhaps you experts can confirm if I am wrong or right !!

Before getting the 400mm, I used my 2X teleconverter with my (non VR) AF-S 80-200 f2.8 Nikkor. It worked OK. The autofocus worked fine.

I think that a mid-priced lens like the 80-400mm f/4.5-5.6 would work better and be less expensive if you don't already have a f2.8 200mm lens. As Tony says, the re-sale value of the pro-quality stuff is good. Less so for the mid priced stuff, but if you buy second hand, that is to your advantage.

Putting a 2X tele-converter on a cheap zoom would be pretty dire, if it worked at all.

Correct. For a 2X converter, an f2.8 lens become f5.6 and a f4 becomes f8. In these days of digital, you can compensate with ISO up to a point, but it is all a quality trade-off. Using a lens that is f8 wide open is horrible. Dingy in the viewfinder.

At the end of the day only $$ lessens the trade-offs. My f2.8 400mm is an extravagance I can't (but did) justify. I just love using it. (And it becomes an f5.6 800mm with the teleconverter. On my D300, this is the focal-length equivalent of a full-frame 1100mm lens.)

Then it wasn't an extravagance, Winky. Just a wise purchase.

Yes, offhand looks like she has the 70-200/2.8 IS. It's a pro lens in the $2K range.

I have to back off on the 80-400mm f/4.5-5.6D lens suggestion. It is a not an AF-S lens and requires an autofocus motor drive in the camera body. The 5100 does not have that. You need a D7000, D300s or better. Bird photography is generally expensive to do well. While you can get by with a lesser body, you still need quality, fast glass and a good tripod.

This is an option. A 300mm AF-S f4 and...

this teleconverter.

The result is a 420mm f5.6 lens with autofocus. Wouldn't be bad, and not too pricey,

I've used this combiation before, and it works pretty well. The 300/4 by itself is high quality and very sharp and one of the biggest bang for buck lenses in the Nikkor lineup. Both the lens and the 1.4 TC can be found used. 

I'd recommend trying an old M42 prime lens with a Nikon/M42 adaptor.

You'd have to set the speed, aperture and focus manually, just like 40 years ago. But given your photos will be taken in good and consistent light levels, once you've set the speed and aperture the only thing to worry about is focus. Buying an adaptor with focus confirm will make focusing quite easy with a bit of practice. 

Start off with a cheap 300mm M42 prime, probably about £30 from ebay. (I suspect on your body, this will give a focal length about 450mm). If you manage to get good results upgrade to something like a Takumar 300mm f4. Takumar lenses are seriously good, I'd suspect far better than a budget Nikon lens.

Plus, getting a good photo setting manually is far more satisfying than a photo produced by the computer in your camera.

I was thinking this exact combination. Might end up with it myself one day.....

I might well end up with this combo too. Thanks Winky.

There seems to be a confusing amount of Nikkor 300mm lenses and more than one f4 - may I ask what is the exact designation of the recommended lens? 

There is only one current 300/4 lens from Nikon: AF-S Nikkor 300mm f/4D IF-ED

The other 300 prime is the far more expensive f/2.8: AF-S NIKKOR 300mm f/2.8G ED VR II

Anything else in the Nikkor range as a 300mm prime would be much older and long out of production.