wingclui44 Loc: CT USA

It's only my own opinion, it works fine if coupling with fast prime lenses at least f4.0 or faster.

mizzee Loc: Boston,Ma

When you look at a teleconverter make sure to check its compatibility list. They don’t work with all lenses. Sometimes you’ll lose autofocus, others they just flat out won’t work and may damage your connections.

imagemeister Loc: mid east Florida

Extenders/converters are only advantageous in GOOD light with:

1. Fast/good prime lenses
2. Fast/good (low ratio) zooms
3. Usually, but not always, with the same brand extender/converter as the lens.
4. slower moving, less active subjects

Otherwise, maximize you native IQ by stopping your lens down a little, not extending to full zoom, using low ISO, and using appropriate shutter speed and support/stabilization to prevent motion blur and CROPPING. Once you have done this you can then use well applied pixel enlargement software to make larger prints or display.
.

camerapapi Loc: Miami, Fl.

A piece of glass in front of a lens should be of good quality or the images will suffer. Buy the one made specifically for your lens brand.
Using a teleconverter means some light is going to be lost. Many photographers go with the 1.4 version. They loose 1 stop of light. The 1.4 version seems to be very popular.
Lenses with f5.6 aperture could show issues focusing using a teleconverter. Check with the manufacturer.
Always consider you are loosing light when working with a teleconverter and consider the ISO speed will need a lift which could bring more noise.

philo Loc: philo, ca

My canon 2x only fits on my 70-200 not worth the money, and it really increases the weight.
Cropping is a lot cheaper.

distill Loc: Huthwaite, Nottinghamshire UK

Well I am not sure if TC are worth it, everyone seems to say get the best or do not use but to me it is simply cost! why when a lens costing over a grand will have lots of prime and rare glass in it, carefully machined barrel and fittings, so it is worth the money and gives great image ( only if the photographer sees it ie. the image). Now having spent over a grand I think I will increase the reach of my lens and get a 1.4 tc, this in reality has bit of a barrel and houses a piddly bit of glass and costs 25% to 40% of my original lens, how can the manufacturers justify this cost, Ah its dedicated to the lens so we can rob you.

Would i see the difference in a large print (without a comparison), doubt it

my favorite quote "in the land of the blind the one eyed man is king"

rmorrison1116 Loc: Near Valley Forge, Pennsylvania

My Sigma 150-600 Sport cost around $2000 and the matching 1.4X teleconverter was around $350. The teleconverter is a precision high quality instrument that does an excellent job when used correctly. The 150-600 with the 1.4X teleconverter effectively gives one a quality 910mm lens. What do you thing a good quality 910mm lens would cost?! $5000, $10,000!?
Let's go with $5000. Would spending $2350 for something that will produce images that are probably 95% as good as something that cost $5000, be a smart decision?! Common sense tells me that, yes, it would be a smart decision but, there are many, many folks that would disagree, possibly yourself among them.
My favorite quote is, "common sense isn't".

bleirer

The reviews on the Canon 1.4 and 2x are quite good. I know nothing of other brands. 7 elements of good glass is not easy to make. One review was comparing a 200 with the 1.4 to a straight 300, and said the 300 was slightly better and had less chromatic aberration. But on the other hand you don't have to carry another lens in the bag, just the 8 ounce extender. Doubling my reach compared to cropping I think is better, don't know for certain.

amfoto1 Loc: San Jose, Calif. USA

Teleconverters work best with certain lenses. In fact, they can't be used at all with some lenses. Particularly with Nikon gear, you have to look into lens/teleconverter compatibility before spending any money on one.

How well a teleconverter works depends a great deal on the qualities of the lens it's used upon...

First, there are different "power" of teleconverters: 1.4X, 1.7X and 2X are the most common. This refers to how they change they effect focal length when combined with a lens. With a 200mm lens, for example, a 1.4X will make for an effective 280mm combo, a 1.7X added to the same lens will make an effective 340mm combo, and a 2X will make an effective 400mm.

But there is a "cost". There is light "lost" to the teleconverter. When a 1.4X is added to a lens, it loses one stop. A 1.7X causes 1.5 stops loss. And a 2X "costs" two full stops. So a lens that's f/4 will "become" an f/5.6 when a 1.4X is added, effective f/6.7 with a 1.7X or f/8 with a 2X. This can cause a camera's autofocus to hunt or fail. It also can dim down the viewfinder, potentially making manual focusing more difficult. Many manufacturers rate their AF systems as "f/5.6 limited" or "f/8 capable" or similar. This pertains to what lens/teleconverter combos are usable on the camera that will still allow autofocus to work. It also may be limited to a specific autofocus point or group of points. (A camera model I use has 65 AF points... the center point is "f/8 capable", so I can use a 2X on an f/4 lens or a 1.4X on an f/5.6 lens... either of those combos make for an effective f/8).

There is also some loss of image quality whenever a teleconverter is added to a lens. How much varies greatly depending upon the quality of the lens and the quality of the teleconverter, plus how well the two "play together".

The stronger the teleconverter, the greater the loss of image quality. Actually, a teleconverter is a complex magnifying lens.... and it will magnify any shortcomings of the lens it's used upon. If a lens has extremely high image quality on its own to start with, then it will tolerate being used with a teleconverter more than a lens with lower image quality would.

In very broad terms, a 1.4X might cause approx. 5% loss of image quality... a 1.7X 10% or 15%... and a 2X may cost 15% to 25%. But, these are just estimates and generations. There's huge variation among all the different lens/teleconverter combinations.

In general, teleconverters work best with prime lenses (i.e., not zooms)... 200mm, 300mm, 400mm, etc. When used on zooms, they generally work best with those that have the least extreme range of focal lengths... 3X (such as 70-200mm) and 4X (such as 100-400mm) usually work pretty well with teleconverters. More extreme zooms such as 28-300mm (10X) or greater usually work more poorly with teleconverters.

There also can be physical limitations. Some teleconverters have a protruding front element that fits inside the rear barrel of the lens. As a result, the lens' barrel needs to be large enough diameter to accommodate that... plus the lens can't be a design that would cause the rear elements of the lens to come in contact with the teleconverter, possibly damaging them both.

Usually a telephoto lens is used with teleconverter combo. It usually doesn't make much sense to use shorter focal lengths with a TC.

Personally I have both 1.4X and 2X teleconverters. Both very high quality OEM.

Overall I use the 1.4X a lot more often... on 300mm, 500mm and 100-400mm lenses. I occasionally use it on a 135mm lens, too. I've tried it on a couple 70-200mm and don't care for the image quality... Other combos may work better than mine, but I also have little use for this combo, since I have several other lenses that cover the same focal length without need for

I use the 2X mostly on 300mm f/2.8 and a lot less frequently on 500mm f/4 lens.

ecurb1105

Teleconverters are iffy. They may work for you or they may not.
They degrade image quality.
They absorbe light and cost you one to three stops or more.
They only work with certain lenses and may physically damage others. Look at Nikons chart for teleconverters.
YMMV good luck.

amfoto1 Loc: San Jose, Calif. USA

Canon 300mm f/4L IS lens with Canon 1.4X II teleconverter on crop sensor camera...



Canon 300mm f/4L IS w/Canon 1.4X II TC on full frame camera (with enlarged detail)...



Canon 500mm f/4L IS lens w/Canon 1.4X II TC on crop sensor cameras:



Or, totally ridiculous... 500mm lens with 1.4X AND 2X TCs, on crop sensor camera (full frame equiv. 2140mm, image is not very usable)...



Recently I also tried the 1.4X TC on my Canon EF 100-400mm IS USM "II" lens. These aren't the greatest shots, but can be viewed a lot larger via the download and their similarity makes them useful for comparison of the lens with and without the TC...

100-400mm lens alone, at 400mm.

(Download)

100-400mm lens with 1.4X TC, at 450mm

(Download)

jpgto Loc: North East Tennessee

B&H is a great source and always very helpful. Good luck.

rmorrison1116 Loc: Near Valley Forge, Pennsylvania

I have both Canon 1.4X III and 2.0X III teleconverter and they are both excellent tools if you know how to use them. The beauty of the Canon teleconverters, although some will disagree, is they will only work on certain Canon L series lenses. I'm sure they will work on aftermarket lenses but I don't believe I've ever tried. This way Canon ensures the user doesn't put a teleconverter on a less than optimal lens thus helping prevent poor quality images due to teleconverter usage. Even Canon can't help prevent bad photos.
Over the years I've managed to collect several teleconverters; the two Canon's, two Kenko, two Tamron, three Sigma and one Nikon and I use all of them; you just have to know how and when.

47greyfox Loc: on the edge of the Colorado front range

I second that!! I've tried Kenko teleconverters (1.4 & 2.0) with lenses they claimed compatibility with. Disappointment reigned supreme.

47greyfox Loc: on the edge of the Colorado front range

Sweet! Very nice! Bravo Zulu!!