incomatible w/ teleconverter

[Tennessee Landscape]

I was reading through the manuals on my two new lenses, and I almost overlooked it but read that niether of the two lenses can be used with a teleconverter....Does anyone know why this would be the case? They're Nikon brand AF lenses, does anyone know why are not compatible. I'm pretty disappointed as I'm on a budget and didn't want to drop a bunch of money on a 400 or 500mm lense...

 

[table1349]

Teleconverters are generally designed to be used with prime lenses with a focal length of 100mm or more. With a 1.4X teleconverte it bumps up your widest aperture by one full stop. A 2X teleconverter will add two full stops to you lenses widest aperture.

I can't speak for Nikon, but with Canon lenses you need at least a maximum aperture of 5.6 for the autofocus to work. That effectively makes you 18-55mm lens a f5-8 and your 55-200 a f5.6-8 with a 1.4X teleconverter. I use a 1.4 with my 70-200 f2.8 but it is a fixed aperture lens meaning that it is an f4 across the focal length. I only use it at 200 mm as well as at the wide end the TC causes quite a bit of distortion.

 

[Happy Hour]

Teleconverters are generally designed to be used with prime lenses with a focal length of 100mm or more. With a 1.4X teleconverte it bumps up your widest aperture by one full stop. A 2X teleconverter will add two full stops to you lenses widest aperture.

I can't speak for Nikon, but with Canon lenses you need at least a maximum aperture of 5.6 for the autofocus to work. That effectively makes you 18-55mm lens a f5-8 and your 55-200 a f5.6-8 with a 1.4X teleconverter. I use a 1.4 with my 70-200 f2.8 but it is a fixed aperture lens meaning that it is an f4 across the focal length. I only use it at 200 mm as well as at the wide end the TC causes quite a bit of distortion.

My camera is the same way but you can turn AF off and just manual focus. now with the pro lenses, they have a shallower space between the body and the camera so you have to use a teleconverter designed just for those lenses. so that the glass doesn't hit it when your focusing

 

[Joves]

Yeah I have the Nikor 80-400 VR and, it is not compatible with teleconverters either. You can use it but, you lose your AF and, if I remember right it also will not meter correctly. I know Sigma makes a couple of zooms that are compatible with their teleconverters. But I think they are all HSMs, too tired to remember now.

 

[Tennessee Landscape]

Thanks all, it makes sense now. I actually took my 55 to 200 back and got a 70 to 300. I'm planning on trying to break into sports and nature photography. Hopefully the 300mm will keep me happy til I can get a big daddy zoom...thanks again.....

 

[sabbath999]

The 70-300 VR is a nice lens, have fun with it!

 

[JerryPH]

I picked up the Nikkor 70-200 F/2.8, and all of Nikon's teleconverters are advertised to work perfectly with it. Of the ones that I know of (the 1.7X and 2.0X), both are excellent additions.

I will likely get the 1.7 when the right time comes.

I think that the reason teleconverters will not work on yours are because they are already quite slow. Putting on a teleconverter you lose 1-3 stops depending on the magnification. So an F/5.6 becomes anything from a F/8 to F/16, rendering them near usless in all but the very brightest of days.

In the case of my choice of teleconverters, it takes my F/2.8 and makes it into an F/4 and at the 200mm range magnifies it to a 340mm... still VERY useable.

 

[nagoshua]

im just wondering.... im getting an f2.8 70-200mm nd a teleconverter, i was thinking of getting the 2x converter but how much distortion will this cause? Also, will the depth of field still be the same as they just cause a fall off in light or am i getting all confuzzled here?

 

[Helen B]

im just wondering.... im getting an f2.8 70-200mm nd a teleconverter, i was thinking of getting the 2x converter but how much distortion will this cause? Also, will the depth of field still be the same as they just cause a fall off in light or am i getting all confuzzled here?

The effective F-number goes up two stops with a 2x behind-the-lens converter - the F-number is multiplied by the same factor as the focal length. This affects both exposure and depth of field, exactly like stopping down two stops.

Remember that the F-number is the focal length divided by the diameter of the entrance pupil. When you put a teleconverter behind a lens it has no effect on the diameter of the entrance pupil (the 'hole' you see through the lens when you look at it from the front). Therefore the focal length changes, but the entrance pupil doesn't.

There are teleconverters that go in front of the lens. Reasonably good ones are very expensive, they are very large and fairly uncommon. They alter both the focal length and the entrance pupil diameter, so they usually don't change the F-number.

Best,
Helen