jeep_daddy Loc: Prescott AZ

I have the new 100-400 Mark II and the 2x will not autofocus because it becomes an f/11 minimum aperture with the 2x installed. It works great with the 1.4x though and on a newer body like the 7D Mark II you can use more than one focus point if you want. I also have the 500mm f/4 lens. What kind of price is being offered for that lens? If it's a good deal, go for it. I use mine on a tripod most of the time but I can hand hold it if necessary. The 500 will work with the 1.4x and the 2x.

chaman

Imperceptible? Unlikely.

amfoto1 Loc: San Jose, Calif. USA

First, the original Canon EF 400mm "DO" simply did not work well with teleconverters... 1.4X or 2X. The 400mm "DO" II purportedly works a lot better with them, but I don't use it and can't say from personal experience.

My advice is to avoid 2X teleconverters, when possible. For the best image quality use no more than 1.4X.

Teleconverters always work best on prime lenses and less well on zooms... though the IQ produced varies greatly depending upon the specific lens and TC combo.

Canon 70-200mm f/2.8L IS USM "II" works very well with Canon 1.4X III and pretty well with 2X III.

Canon 100-400mm L IS USM "II" works well with Canon 1.4X III.

Canon cameras that will autofocus with an f/8 lens & TC combo...

Full frame:
- 1DX Mark II (all 61 points)
- 5D Mark IV (all 61 points)
- 1DX (center AF point out of 61 AF points, four surrounding points "assist", requires later firmware version)
- 5D Mark III, 5DS, 5DS-R (center point of 61 AF points, four surrounding points "assist", 5DIII requires later firmware)

APS-C Crop sensor:
- 80D (27 of it's 45 AF points)
- 7D Mark II (one center point of it's 65 AF points).

Older full frame 1DS models and APS-H 1D models also have some f/8 capability (typically center point only, out of 45 total AF points).

All other Canon cameras are "f/5.6 limited", meaning that when they detect a lens/TC combo that makes for an effective aperture smaller than that, they are designed to turn off AF and force you to focus manually.

Keep in mind that 100-400mm with 2X will be an effective f/11 at the long end (anything longer than approx. 300m in the zoom range). Not only will the AF turn off, but the viewfinder will be heavily dimmed down as well, making manual focusing difficult. Focus Confirmation also will not work, when AF is disabled due to the lens/TC combo. So that's not available to help you manually focus, either.

Some things you can do....

#1. If using a full frame camera, consider supplementing it with an APS-C model, particularly for long lens use. This will be sort of like getting a "free 1.6X teleconverter". By "free" I mean that unlike an actual TC, there's no "light loss". On my APS-C 7D Mark IIs, my 100-400mm II lens "acts like a 160-640mm" would on my full frame 5D model. That makes for versatile, sharp lens and a 20MP image. Cropping a 5D III's 22MP FF image down to the same amount would leave you with only about 9MP... cropping a 5DIV's 30MP down the same would leave you about 12MP image. Not bad, in either case.... but not as good as 20MP! BTW, 7DII's sensor density is almost identical to the 50MP 5Ds-models', except the ISO range of 5Ds/5Ds-R is 100-6400, expandable to 50 and 12800. 7DII's is 100-16000, expandable to 25600. About a year newer than 7DII, 80D offers 20% more resolution with a 24MP image on APS-C, as well as more f/8 capable AF points (27 versus 1 in 7DII). 80D has slower continuous shooting rate (7 frames per second versus 10 fps with 7DII) and it's not as tough or well-sealed a camera, and maybe not quite as fast-handling... But it has same ISO range and many think offers the best APS-C sensor from Canon to date (a wee bit higher usable ISO and a little greater dynamic range).

#2. If using a TC/lens combo that exceeds the camera's AF rating, it's possible to tape up a couple of the contacts on the TC so the camera doesn't know it's installed and will still try to AF. One minor drawback is that EXIF metadata in images will be incorrect... it will only show the lens focal length. This also might effect distance info if using ETTL II flash. And you also should expect AF performance to decrease significantly... more AF hunting and failure to lock on. How good or bad AF works will depend a lot upon ambient lighting conditions, subject contrast, etc. If interested in trying this, Google for more info online. I know I've seen web sites that show which contacts to tape up, but don't have a link handy.

#3. Live View might be helpful if the viewfinder is too dimmed-down for manual focusing. Enabling Exposure Simulation in Live View can brighten the image displayed on the LCD screen. Also, you can magnify the Live View image to check manual focus.

Personally I use the Canon 1.4X II and 2X II teleconverters.

The 1.4X II I use on Canon 135/2L, occasionally on EF 70-200/2.8L IS USM (rarely, there's a lot of loss of IQ on the original f/2.8 version), frequently on EF 300mm f/4L IS USM, EF 300mm f/2.8L IS USM and 500mm f/4L IS USM. I have not yet had occasion to try it on EF 100-400mm IS USM "II" which I added to my kit last year (and use a lot on 7DII). I also haven't tried it on EF 70-200mm f4L IS USM zoom.

I use the 2X II almost exclusively on EF 300mm f/2.8L IS USM, occasionally on my 500mm... never on any zoom. Image quality takes a much greater hit with a 2X.... where there might be 5% loss with a 1.4X.... there's probably more like 15% or more loss to a 2X. But there's huge variation in the degree of loss of image quality, depending upon the exact lens/TC combination.


Canon EF 500mm f/4L IS USM with EF 1.4X II, on Canon 30D (APS-C, 8MP)

The Canon "III" teleconverters are also said to be quite good. Personally I did not see need to upgrade from "II"... In part that's because I simply don't need to use wither with zooms. I have prime lens and TC combos that work very well and make that unnecessary.

I've also heard a lot of good things about the Kenko 1.4X, which are a whole lot less expensive. Their cheaper "MC-4" is quite sharp in the center, some think even sharper than the Canon, but less so in the corners and at the edges. Often some corner softness doesn't matter very much for wildlife photography. But if it does using that TC on an APS-C camera will mostly just use the "sweet spot" of the image area. If you will be using the TC on full frame and want better edge-to-edge and corner-to-corner sharpness, the Kenko "Pro 300" model might be preferable. It's slightly more expensive (though still about 1/3 the price of the Canon "III"!) There are Kenko 2X MC-7 and Pro 300, too... though I don't know how they compare.

If you'd like to compare for yourself, Bryan Carnathian's the-digital-picture.com has both sample images and magnified test shots done with many lenses and lens/TC combinations. You can compare side-by-side there, too... at different apertures, various zoom focal length settings, with and without TC, and on different cameras. For example, http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=972&Camera=979&Sample=0&FLI=4&API=1&LensComp=972&CameraComp=979&SampleComp=0&FLIComp=5&APIComp=2 shows the 100-400mm II wide open performance without any TC at 400mm (left) and with 1.4X III at 560mm (right). Switch the right hand display to 800mm to see how it performs with 2X III. You also can choose smaller apertures to see how it improves and compares. At that link the test shots are all done with 5Ds-R.... just about the most demanding camera available. You may be able to switch both over to another camera model that's more like what you use. (Note: I compared the 400mm "DO" original with 2X II against the 400mm "DO II" with 2X III and the newer combo certainly looks a lot better to me!)

JayB Loc: Northeast US

Thank you! A lot of information in this. I've been checking out lots of your pictures. They are stunning and jaw-droppingly sharp (though one of my favorites is the Harrier at dawn in fog). Are all of the 2017 shots taken with the DO? Your comments about using a Hi-Res body was interesting. BTW, I'm no longer considering the 100-400 IS II for these purposes. I might get one anyway at some point to replace my original version. But I understand it doesn't really answer this particular need. Thank you again for your help.

JayB Loc: Northeast US

Awesome. Yes, I find myself doing that sometimes anyway. TTL focusing at f11 though. I don't mind manual focusing, but I like to see what I'm trying to focus on. But great to know that IQ is good. I love the 100-400 and would buy the new version for what it does even without any extenders. Thanks for your thoughts and information. Really helpful.

JayB Loc: Northeast US

Wow. Thank you for that. You have the distinction of FINALLY helping me understand the mysterious crop-factor advantage of an APS-C camera. This fabled extra reach when there is no extra reach. I finally gave up asking on this forum. It was inciting riots. Well, maybe not quite that bad. Even seasoned photographers would say that it was just a marketing scheme. One person stated that I just didn't understand. She was correct but it wasn't helpful. Now I GET IT! Moving along, I've spent quite a lot of time on The Digital Image site. Most of the time, the results concur with what one expects. But I'm seeing lots of images with the DO using the 2xIII that are very detailed. Sometimes a little too detailed and I wonder if that's the lens or PP. Anyway, a lot to digest in your generous post. I'd love to trial that lens with my Mark III and with some of the latest high-def model. I'm not that much of a fan of the hi def look so I'm actually hoping that my MarkIII will keep things a little more "vulnerable" with the DO. Another concern is specular bokeh I've noticed. One user of that lens consistently shoots at rather high f/stops even when there's room to open up. I wonder if that's to avoid the bokeh issue. There's no arguing that the new DO produces spectacular images. I've been blown away by many of them. But is it art?

chaman

Marketing scheme?! LOL! I wonder what clown said such a thing.

JayB Loc: Northeast US

I'm sure they were just exasperated by my dunderheadedness and said it to shut me up. But the answer is very logical. I just wonder why no one was able to simply state it.

imagemeister Loc: mid east Florida

For those having a serious interest, here is a link comparing all canon 400mm lenses with MTF https://www.lensrentals.com/blog/2016/08/the-sort-of-great-400mm-shootout/ -

Nalu Loc: Southern Arizona

I usually include the lens and camera body info on my posts. Almost everything I post is either with the DOII plus 1.4x III converter (560 mm) or the 600mm IS II with a 1.4 (840mm) (I have 2 1.4 converters and one 2X). Appreciate the complements on the photos and I also love the Harrier shot in fog (a serine morning at the Merced national wildlife refuge). We were actually hoping for incoming sandhill cranes before dawn but they didn't show up. Again, good luck with your decision. I have had the 400 DO II for almost 2 years and love it. I hardly ever use it on a tripod. Not as light as the 100/400, but definitely hand holdable. I keep usually keep it on a 1DX for flight. But I lean most of the time now on my 600mm IS II with a 1.4X mounted on a gimbal head with a 5DIV. The 5DIV is amazing camera and I am trying to not do the burst thing unless something really special shows up. At 7 fps I am finding the 5DIV fast enough for most stuff, but the speed of the 1DX is handy at times. The sensor on the 5DIV is pretty dam good, allowing for some pretty good crops without too much loss. With the encouragement of Artie Morris I have been experimenting with a 2XII on the 600 as well and am seeing some pretty reasonable results. His results are excellent so I know in the right hands the 2x on prime lenses can produce. So the optics are there and its a matter of the operator to get good results. If you can swing he 400 mm DO II you will love it.

JayB Loc: Northeast US

Epilogue: Passed on the 400 IS II DO. I bought the older EF 500mm f/4 IS for now. Soon to be followed by the 100-400 IS II with the 1.4x and the 5DIV. Thanks for all of your great comments.

RRS Loc: Not sure

You will be very happy with the 500mmf/4.0 and it works very well with the 1.4.

JayB Loc: Northeast US

Thank you! That's what I hear. [big grin]

JayB Loc: Northeast US

And thank you for commenting.

Nalu Loc: Southern Arizona

Good choice. I would get the 5DIV first, then the 100/400. You will really pleased with the body.