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Canon Lens EF 70-200mm L F4 USM+ 2X L series extender


Hi, I have a Canon Lens EF 70-200mm L F4 USM. Now I want to purchase a 2X L series extender. Can anybody help me by informing that AF can work with EF 70-200mm L F4 USM + 2X extender mounted on 650D camera and how much picture quality I have to compromise for the same.


@mithun_pal129 wrote:

Thank you all for your valuable comments. I forgot to mention that my intension of extender to make my EF 70-200mm L F4 USM to a telephoto lens for wild life / birds. But now as I am staying in Abu Dhabi, there is not much scope of bird / wild life. Hence I don't want to spend much on super telephoto lens and personally I don't want to go for cheap Sigma lens. So I wanted to make 70-200mm lens + 2x extender as 140-400mm. As I got impression 1.4X extender is pretty good but it will give me upto 280mm. I know it is not very good focal length for bird / wild lift photography. But want to know still is workable or if I use 2x extender to make the lens 400mm the auto focus is required for wild life or manual focus can still work at F8. I don't have much experience in wild life photography that is why I wanted to know the things.

In a nutshell... No.


Putting a 2X teleconverter onto a 70-200/4 makes for an "effective" 140-400/8  lens. Due to the reduction in light reaching the AF sensors, your camera will turn off auto focus. A stronger 2X also will "cost" more loss of image quality due to degradation.


It is possible to tape over some of the electronic contacts on the teleconverter, so that the camera doesn't know it's there and will still try to auto focus. However, auto focus will be much slower and will tend to hunt a lot more.


In some situations you might be able to focus manually. However, effective f8 makes for a pretty dim viewfinder, plus modern auto focus cameras like yours do not have some fo the features to assist manual focus, that vintage cameras designed for manual focusing had in the past. Some people change out to a third party focusing screen to add manual focus assist features (split image finder, micro diaprisms, for example). However this requires some careful work to install the focus screen and the different focus screen can effect the camera's metering accuracy, especially making Spot Metering inaccurate.


 Adding a weaker 1.4X teleconverter makes your lens into an effecive 112-280mm f5.6, which will still autofocus and will have considerably less loss of image quality, though not as much "reach". If yours is an IS lens, it might be reasonably handholdable. If it's not an IS lens, you will need to watch your shutter speeds more carefully, probably will want to keep to 1/500 or faster to prevent camera shake blur. Or use a tripod, as ebibgs suggests, or at least a monopod. You also will need to limit your camera's autofocus to the center AF point only, I believe.


@ebiggs1 wrote:

On your camera the 70-200mm f4 acts like a 112-320mm f4.  With a 1.4x converter you are looking at 448mm on th elong end and f5.6.  400+mm should be long enough for you to get some bird shots.  BTW, use a tripod.


While it is technically correct, citing the "crop camera lens factor" this way may not help very much, might be confusing.


The original poster simply has a 70-200mm lens that they are accustomed to using on a crop sensor camera. Now they would like to double the reach of that lens on their camera. Bringing crop sensor lens factor into the conversation is most useful when the user is going from film/full frame to crop camera or vice versa. To someone who has never used a film camera or hasn't used one in many years and is now completely accustomed to how a lens focal length performs on their crop camera, it is a completly moot point.


But what it comes down to is that while you can add a 2X, it's probably not a good idea for several reasons. Auto focus won't work or, with some tricks, will work only poorly. Manual focus will be difficult. And the image quality might take too big a hit, pairing up a 2X with your lens. .


I have 70-200/4 IS, 70-200/2.8 IS ("Mark I"), 1.4X II and 2X II teleconverters. I also have longer telephoto lenses, so rarely have need to add teleconverter to these zooms. However if needed I would use 1.4X on either of them. But even though AF still works on the 70-200/2.8 + 2X combo, I won't use it due to the amount of image quality loss (the newer 70-200/2.8 IS Mark II and 2X Mark III are said to work better together, than my older versions of each). 


I mostly only use the 2X on 300/2.8 and 500/4 prime lenses, where image quality is still good. (Note: yes, on some of my cameras the 2X on 500/4 causes AF to stop working, just as it would on your f4 lens, so I only use the combo in a limited way.)


mithun_pal129... At most I'd suggest you get a 1.4X and use that  with your lens. See if the image quality is up to your expectations. Then work to get closer to your subjects. Or get them to come closer to you. Practice stalking techniques and study your subjects' behaviours to discover ways to get closer. Work from a blind and use attractants (food, calls). And start saving up for a longer focal length lens.


The Canon 1.4X II and III teleconverters are excellent. All Canon teleconverters have protruding front elements which limit the lenses they can physically be attached to, but the 70-200s are among those where it's possible. Kenko teleconverters are another that I see recommended quite often. They have two different quality levels: A more expensive "Pro 300" version and a less expensive "MC-4". These currently are offered in "DGX" versions that function very much like Canon teleconverters. Older Kenko "DG" teleconverters did not "report" to the camera, the camera didn't know they were there, so would try to focus.  From the reviews and tests I've seen, the current Kenko DGX Pro 300 is quite good across the whole image area. The cheaper MC-4 is actually slightly sharper at the center, but not as sharp in the corners and at the edges of the image. Tamron and Sigma also make teleconverters, but I have little experience or knowledge of current versions of those.


Wildlife/bird photography isn't easy. No matter how long a lens you have, there will be times when the subjects are just out of reach and all you can go is sit back and enjoy the show.


These photos of small subjects were shot with various lenses, but close to or less than the same effective focal length as your 70-200mm + a 1.4X teleconverter would be on your camera...


Hi mom!


Waxwing brunch


Redtail hunting


Goose in a new day


Alan Myers

San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7D(x2), 50D(x3), some other cameras, various lenses & accessories


View solution in original post


The EF 400mm f/5.6L USM lens is a great lens. I use my 100-400 a lot, but I do so handheld most of the time. But, if I were using the 400mm prime I would want to use it on tripod, due to its’ long FL.

Using a super telephoto lens has learning curve. You have to get used to viewing the world through a straw. The longer the straw, the harder it is to get your bearings. This is one advantage of a zoom. You can back to reacquire a subject, and back in again.

I like the advice to pass on an extender. If you plan to use the extended FL most all of the time, then you are better off with a lens with the native FL.
"The right mouse button is your friend."

Yeah, this is clear, but thank you for warning for me. 😉

What do you think the EF 300mm f/4 L IS USM lens? This would be better for the IS, even if I lose a hundred mm-s...

"What do you think the EF 300mm f/4 L IS USM lens?"


I love that lens.  It is a buy and it works well with the 1.4x tel-con. That results in a 420mm f5.6 lens with IS.  A win, win win.

Without the tel-con the 300mil is very sharp and a fast f4.

EOS 1DX and 1D Mk IV and less lenses then before!

Wowza, thats sound good! 🙂 Plus the 80D crop (1,6x), and final results absolutely fabulous!

"Plus the 80D crop (1,6x), and final results absolutely fabulous!'


Yup, good and bad!  You are looking at nearly 700mm equivalent there.  All the good is added but all the bad is added, too. Remember there is no free lunch in photography. You give to get. It will take some time and practice to get the best out of it.

EOS 1DX and 1D Mk IV and less lenses then before!

Yes, you are absolutely right in this. 😉

Canon EF 300mm f/4L IS USM on APS-C camera (7D)...


Waxwing brunch


EF 300mm f/4L with EF 1.4X II teleconverter on APS-C camera....


Valley coyote


EF 300mm f/4L IS USM on full frame camera (5D Mark II)...


Red tail hawk flyby


Enlarged detail from above...


Red tail hawk detail


EF 300mm f/4L IS USM with EF 1.4X II teleconverter on full frame camera (5D Mark II)....


Black tail mule deer buck


Enlarged detail from above image...


Black tail detail


The Canon EF 300mm f/4L IS USM is an old model, first introduced in the mid or late 1990s I think... But it's still in production and still a great lens. The lens alone is right around 3 lb. and the Canon 1.4X only adds another half lb.... so it's all pretty easily hand held. It has fast autofocus and image stabilization to help with handheld shots (all the above except the mule deer were hand held... for that I used a monopod).


The 300mm f/4L is pretty darned sharp, even with a 1.4X teleconverter. The 400mm f/5.6L lens alone is probably sharper than the 300mm with 1.4X... It's a great lens, but the EF 400mm f/5.6L USM doesn't have image stabilization. I also prefer that the 300mm and a 1.4X teleconverter give me two different and useful focal lengths to work with: 300mm with the lens alone and the 420mm combo.


The 300mm f/4L IS USM also is one of the closest focusing of the Canon lenses longer than 200mm. It gets to almost 1/3 life size without any assistance, but can be made even closer focusing with macro extension tubes. (In comparison, many of the far more expensive super telephotos only manage 1/4, 1/5 life size or less.) This image of a spider is slighlty cropped, but was shot with 300mm f/4L IS without any added extension tubes (hand held, on APS-C 7D camera)....


Spider on fence post


I've used the 300mm f/4L extensively for sports and wildlife. It has a few very minor quirks. For example, notice the purple or magenta higlight in the hawk's eye above. That's common in specular highlights with this particular lens. It's super easy to fix, if wanted, in post-processing. I didnt bother fixing it in this image because I don't feel it detracts in any way.


As an older design, the 300mm f/4L also uses a more "primitive" form of image stabilization. It doesn't give quite as much "assistance" as some of the newer ones... maybe two to three stops worth (newer can give up to four stops). Still, the IS is very helpful. More importantly, the type of IS system this lens uses needs to be turned off by the user IF the lens is fully locked down on a tripod or being used in any other way where there's no movement for the IS to correct. When there's absolutely no movement, the IS in this lens can go into sort of a feedback loop where it's actually creating movement and can cause shake blur in images. So it needs to be turned off at the switch on the lens (most other Canon IS lenses self-detect and turn off IS automatically). Using this lens hand held and occasionally on a monopod or a "loose" gimbal on a tripod, I can't recall ever turing the IS off.


Overall, I like the 300mm f/4L enough that I bought a second one! My oldest one is down with some problems with it's IS system. That older lens was used extensively for many years, so I'm not surprised it needs some service work.


More recently I got the Canon EF 100-400mm L IS USM "II" and have been working with that zoom a lot for similar purposes. It is a bit bigger and heavier than the 300mm f/4. It's also a larger diameter which I find tires my hand holding it a lot faster during extended shooting sessions. As a result I'm more likely to use this zoom on a tripod.... Something I rarely have done with the 300mm lens. I've often shot with the 300mm hand held for 4, 6 or 8 hours, with just an occasional break. 



Alan Myers
San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7DII (x2), 7D(x2) some other cameras, various lenses & accessories







Thanks for this complex and detailed answer, you helped a lot. Presumably I will choose this lens.

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