DWU2 Loc: Phoenix Arizona area

I agree - I get OK results with my Canon 70-200 f/2.8, but with my Sigma 150-500, results are unacceptable.

CHG_CANON Loc: the Windy City

HORSESH** - wotsmith, you took the exact words out of my mouth on several of these nonsense, uninformed responses. 25% reduction, Gene - quit making stuff up .... notorious for problems - Lorendn, go join Gene in the recovery center ...

If you're talking about mixing brands and / or non Canon equipment, can't say if you're right or wrong. But, that wasn't the question asked by the OP, so why are you chiming in?

As shown above and cross-referenced by others responding with images created right now in 2016, your responses are factually wrong.

Haydon

Sorry Regis, your statement defies physics. I can even see a small degrading on a Canon 500 F4 with a Canon 1.4x III. It's mostly a small hit on clarity & sharpness. I can't speak for a 2x but there's plenty of supporting tests that suggest 20+%. Teleconverters seem to also rob you on focus speed as well. Arthur Morris is a huge advocate on both the 1.4x & 2.0x and highly recommends them for prime lenses. I still say using them sparingly is the best practice.

wdross Loc: Castle Rock, Colorado

It all comes down to design. Olympus does not recommend using the 1.4X and the 2.0X on every lense and makes a specific 1.4X for just a few of the pro lenses. Why? Some of the lense designs work well with certain teleconverters and some work well with the specific specialized teleconverter because of design. If the teleconverter design was done with specific lense designs for use, there will very little noticeable image lose (even to the point of negligible). But if it is a generalized teleconverter design, it is not beyond believing the image loss of 25%. I have an old film designed 400mm lense that is just acceptable with the 4/3rds but is totally unacceptable with a 2X converter.

LoneRangeFinder Loc: Left field

Well all I can say is sharpness is in the eye of the beholder. Is it works for you, fine-- but it ain't "tack sharp."

wotsmith Loc: Nashville TN

Amen to Regis' response; see also Art Morris -birdsasart.com BTW the eagle shots are hand held as well, What sharp photos with out a tripod??? You thought impossible? the proof is in the pudding. Check out Regis' eagle photo - down load and change your mind about extenders.

Gee, maybe poor technique or poor equipment is responsible for "soft" photos with tele extenders.

Regis Loc: Coeur d' Alene, Idaho

Have it your way. I won't argue with a man who has his mind made-up.

Regis Loc: Coeur d' Alene, Idaho

Thank you, wotsmith.

amfoto1 Loc: San Jose, Calif. USA

Yes, it would be better to remove the teleconverter if shooting under 400mm (in this example).

A teleconverter always costs some image quality... especially when use on a zoom rather than a prime lens. And a 2X costs more image quality than a 1.4X teleconverter.

A high quality 1.4X on a high quality prime lens might only "cost" 5 or 10% of image quality. A 2X is likely to impact image quality 15 to 25%.

Also, in your example I think you will lose auto focus.

AFAIK, only Canon makes a 100-400mm lens, so I'm guessing that's what you're using. If so, Canon's 100-400mm are variable aperture lenses that are f5 up to about 300mm and f5.6 beyond that. Adding a 2X to the lens makes for an f10 to f11 combo, which won't auto focus on any Canon camera. A 1.4X only "costs" one stop of light and makes for an f7.1 to f8 combo with 100-400mm, which can only autofocus on certain Canon models: 7DII and 5DIII (center AF point only), 80D (at 27 of its 45 AF points), 5DIV and 1DXII at all 61 points. Most other Canon cameras are "f5.6 limited" and will not be able to AF the 100-400mm with a 1.4X on it.

I've frequently used 1.4X with various f2.8 and f4 telephoto lenses, mostly primes but also occasionally with 70-200mm zoom. I also have used 2X sometimes, but only on primes and mostly just f2.8 lenses. (Both my 1.4X and 2X are high quality Canon TCs.)

At Internet sizes and resolutions you won't see much difference. When I'm shooting an event and can't move around much to shoot from different angles or closer up, I'll often first shoot without a TC, to be sure to get as sharp as possible shots of all the participants. Then I'll add a TC to get a series of tighter shots. Here's are a couple examples... Both shot with Canon EF 300mm f4 IS USM lens... the first without any TC, the second with Canon 1.4X II.



IMO, both look fine at these resolutions and sizes... But I can see some slight difference in quality viewing the original, full size images enlarged on my computer monitor.

mas24 Loc: Southern CA

I have a 500mm f8.0. reflex lens. I haven't used it in years. Never thought to use my 1.4X TC on it. It wasn't real sharp to begin with, but I'm curious as to how much degradation will be noticed.

CHG_CANON Loc: the Windy City

Shooting lines on a chart in a lab has only one audience: people who buy shots of thin lines on a chart from a lab. Most images with an extender are 100% sharper than no image at all.

If you can use a prime that covers the same focal length as a smaller lens with an extender (and you can afford that prime), you'll be better off with the prime. But, there aren't any 1000mm or 1200mm lenses on the market for the general public.

In the Canon line-up, regularly there are posts from people who buy an extender first and do their homework second to find their camera doesn't have any AF points sensitive to f/8. And they blame their equipment instead of their lack of knowledge.

And then there's the crowd that says the Canon extenders are not any good. Or quote a random number / percentage that reeks of truthiness. Was the dragonfly earlier or the Mustang below degraded by the use of an extender? By some specific percentage? Nonsense says I. The only percentage that can be independently verified is that neither would exist with 100% certainty had the equipment used not been available for either of these scenarios.

There's trade-offs. The 100-400L and a 1.4x extender is a whole lot cheaper and the combo is smaller in size & weight than a 500L or 600L. And 'cheap' is a relative term given the new version of the zoom is 4-figure investment plus a top-line camera to drive the combo. (Even the ver I and the 1.4III is 4-figs and still requires a top camera.) But these comments saying that using an extender is at best 90% as good and probably as low as 75%. This crowd is just ignoring the facts or they're laboring under conceptions of reality that do not exist in today's reality. Or maybe, shooting lines on a chart is more important to them than capturing images of things out in the world.

P-51 Mustang 'Baby Duck'; by Paul Sager, on Flickr
http://c3.staticflickr.com/9/8336/29474610570_ed38a1dd32_b.jpg

wdross Loc: Castle Rock, Colorado

The original question posed by JayHT in his paragraph was should he shoot the 200 - 400mm range with or without the teleconverter. He wanted to know which was best and why. The most accurate answer is without the teleconverter. No one has told him not to shoot with the teleconverter on the lense. Anyone who is a true photographer is going to take the picture first and then see if they can improve it to the max. If that means then taking off the teleconverter because one has time and the future shots will not be greater than 400mm, one should do it. If there is doubt that 400mm is going to be long enough, don't take it off. With his combination, there probably will be little apparent difference in an 11 X 14 or smaller at a proper viewing distance. And unless it is a side by side comparison of larger prints, the differences may not be that obvious in larger prints. But to say that there are no differences is to say that sales figures lie. Why would anyone put the money out for a five or six digit costing lense when they could get an "equal" lense using just a teleconverter? There are articles on using two teleconverters, a 1.4X and a 2X, together and which order to put them in. That is because the designs of the teleconverters work acceptably with one order and unacceptably with the reverse order. Again, it comes down to the design of the lense and the design of the teleconverter as to whether the change in the image quality is negligible or profound.

wdross Loc: Castle Rock, Colorado

JayHT, as you can see there is much opinion on the subject. I think I will suggest the best answer to your question is your own opinion. To best answer your own question, pick an area with close and distance stationary subjects that you might actually shoot. Then shoot those subjects at 200mm, 250mm, 300mm, 350mm, and 400mm with and without the teleconverter. Use the same techniques as you would for normal shooting. Blow them up as large as you would expect to if you were going to print these pictures. Compare the with and without images for the 200 - 400mm range. You will then be able to decide if your teleconverter, shooting style, and required image quality are going to be acceptable to you. It really comes down to what you find acceptable, not what we feel is acceptable.

CHG_CANON Loc: the Windy City

Jay / all - the original 100-400L benefited from stepping down to f/8 even before adding a valid extender. But, if you want to use a 2.0x as referenced in your OP, you're turning an autofocus lens into a manual focus lens. For me, there's no reason to even bother with this combination.

But, if you have the light and the settings, your loss is negligible image-wise using the 1.4x III even where the situation doesn't require it. You're more likely to gather sensor dust or dropping equipment adding / removing extenders worrying about image quality over the 200-400 range ...

There's been a side discussion elsewhere on AF performance. Again, if your camera body can't drive an f/8 configuration, this whole discussion is worthless for a manual focus configuration. My experience is the best performance is continuous AF and back-button as the extenders do add a 'lag' to the AF performance where continuous seeks to overcome that lag.

JayHT Loc: NorthWest Washington

To All,

Thanks for the opinions that members have expressed regarding the use of extenders. I am planning a trip to go out to the field so that I can experience what members have experienced in forming their opinions.

Thanks once again for sharing your experiences.

JayHT