OllieFCR

I recently purchased a Canon 1.4 extender to go with my 100-400mm Mark II Canon lens and 7D Mark II camera. As a test I mounted the camera and lens on a tripod with and without the extender. At 400mm I took pics of a sign some distance away with various sizes of text. When the photo without the extender was cropped to the same size (i.e. content) as the one with the extender it had significantly better resolution and contrast than the photo with the extender. I was surprised and disappointed by this. The question is then, why use the extender given the extra expense and loss in aperture?

Hank Radt

Very interested in the responses to this - have been thinking about getting a 1.4x, but this is the first time I've seen this issue raised. Thanks for posting.

Cdouthitt Loc: Traverse City, MI

It depends on the lens and tele extender. My 1.4x and 2x extenders give me the extra reach and are still perfectly sharp wide open. My 150 f2 becomes a 210 f2.8 and 300 f4.

Erv Loc: Medina Ohio

Well I have the 1.4 and the 2 extenders. They were fun to play with, but they spend most of the time in the camera bag.

PixelStan77 Loc: Vermont/Chicago

Welcome to UHH. The reality is that you do get reach with an extender but pay a price in resolution. My view is that an extender takes a good lens and degrades it for reach. I have proved that with resolution charts. It even gets worse if the extender is not the same brand. If you can, I would return the extender.

OddJobber Loc: Portland, OR

Did you try focus fine tuning the lens with the 1.4X attached?

joer Loc: Colorado/Illinois

A good number of people with experience have been saying this right along. I suspect it has a lot to do with the lens and camera being used.

I sold mine a long time ago.

CHG_CANON Loc: the Windy City

You want the largest subject focused on your sensor. Extenders (Nikon teleconverters) help to do this.

The resolution of the newest cameras give head-room for significant cropping that was unheard of even as recently as 2015. You may find cropping is all you require given your usage needs. You should also recognize the 'sweet spot' of your lens is moved when working with an extender. I get a lot better results for an extended 100-400L II at f/11 and 560mm than the maximum f/8 aperture. The AF fine-tuning option for your 7DII also should be considered. Below is an example result that can be captured at 560mm.

Chicago area Dragonflies by Paul Sager, on Flickr
http://farm8.staticflickr.com/7577/27357692983_b36c924717_b.jpg

OllieFCR

I should have added that I manually focused in both cases.

OllieFCR

I did return it.

PaulR01 Loc: West Texas

Ill give this reply as a freelance sports shooter. If I shoot an image and crop it at 75% and have a great image I can post it on the internet or print a 8x10 of that image. Other wise its useless What happens when a customer want a 16x20 or larger print or poster. Or the editor I am working a project for want this photo as a lead for a magazine or newspaper as a full page shot? I can still get a workable image in post with a large file size with a teleconverter. Not every image is destine to be a work of art hanging in a gallery. A slightly softer image catching the moment that is still acceptable is a better option. I use large prime Canon lenses most football and baseball games and a version ii 1.4 during daylight games. And the fall off is minimal as best.

OllieFCR

Thanks. Your advice is very reasonable. I am mostly shooting birds as amateur. Most are posted on internet and sharpness is very key with birds.

MT Shooter Loc: Montana

Did you manually focus in Live View or through the viewfinder? If through the viewfinder, was your diopter correctly adjusted? This can make all the difference! I have shot that exact combo and while I agreee there is some image degradation with the Extender, I found it was not severe at all and was quite acceptable in lieu of a longer lens. An Extender is never a "solution", it is merely a crutch when more reach is needed and not available.

OllieFCR

Live View always.

mwsilvers Loc: Central New Jersey

Micro focusing the lens/extender combo might help a bit. I also don't think you mentioned which version you have. The Canon 1.4 Extender III, the current version, is noticably better then the previous versions. Also some have found there is a bit of a learning curve to get the best from a extender/teleconverter which may be part of the reason that some folks are more successful than others.

Finally, some people are pixel peepers or crop alot or just have higher expectations and easily notice any image degradation. There are also some people who have lower standards. I've seen God awful images on these pages, taken with teleconverters, that are praised to the hilt. They are often soft with poor contrast and yet people don't seem to notice.

I have also seen some exceptionally good images taken with Canon extenders by people with top-notch equipment who know what they're doing. In the end, even after practicing with one, if it doesn't work for you, the solution should be clear.

I bought a 2x Extender III to use with my 7D Mark II and Canon EF 70-200mm f/4 L IS USM. No matter what I tried, hand held or on a tripod, I was unable to get more than a handful of images that were close to acceptable to me. After a couple of weeks I just gave up and returned it. I'm not a birder and rarely need 400mm so I ultimately decided that for me the 2x extender wasn't worth the cost or effort. I would have tried the 1.4x, but at the same price as the 2x version, the additional 80mm of reach on my lens didn't seem cost effective. I do know some people that use a combination of your lens, your extender, and your camera, who get outstanding results using autofocus. Of course, at an f/8 maximum aperture only a single point is available for AF on your camera.