Karl Howells Loc: Jessup Pennsylvania

Hello everyone this is my first attempt on UHPF was looking for any results/opinion with using a Canon 1.4 Extender EF 1.4x III with a Canon 400mm f5.6 and a sigma 18mm-300mm combination these are the two lens I walk around in the woods with. Some times the 400mm is just not large enough. Would spending the $400+ for the converter be worth it. I shoot with a T7i.
Thanks
Karl

Jamiesonjjj

Don't think it will fit anything over 2.8.

CHG_CANON Loc: the Windy City

See the note at the bottom of page 134 of your EOS T7i manual. Combing the 1-stop loss of light to an f/5.6 lens may cause problems in low-light situations. Your Sigma lens likely cannot physically be connected to a Canon-brand extender. You should hesitate purchasing a 1.4x until you clearly understand the performance and technical compatibility of this tool with your candidate body and lenses. The Canon extenders have compatibility to a limited group of only Canon's L-brand lenses, although that limitation is not limited to the maximum aperture of the supported lenses. The EF 400 f/5.6L may work fine for your needs in the best light. The T7i manual details all of the supported Canon lenses and Canon extenders on pages 135-138.

Karl Howells Loc: Jessup Pennsylvania

Thank You CHG Canon, unfortunately the manual that came with my camera did not have that information that's why I was asking, I did look for a different manual on line and did find it with the information that you have provided/referred me to. I may just rent the 1.4 for a weekend and try it out. Thanks again.
Karl

howdysmom Loc: the Northwoods of Wisconsin

Here is a link to everything you need to know about Canon extenders. I found this very useful in deciding whether to get a 1.4 http://learn.usa.canon.com/resources/articles/2013/ef_extenders_pt1.shtml

dsmeltz Loc: Philadelphia

Title says the version II the text says the III. Which one are you asking about?

the f/stops here Loc: New Mexico

Simply put, the 1.4 extendor will work well with the 400mm lens and will not work at all with the sigma zoom or any other zoom in that range. You will enjoy the 560mm’s for wildlife.

mwsilvers Loc: Central New Jersey

Since your camera supports up to 27 auto focus points with a lens/extender combination maximum aperture of f/8, the EF 400mm f/5.6 should work. The Sigma definitely WILL NOT work. In the event you're even considering the 2x version, which is around the same price as the 1.4x, that would bring the combination's maximum aperture to f/11 and you would not be able to auto focus.

mwsilvers Loc: Central New Jersey

And of course with his t7i's crop factor, the 35mm equivalent angle of view would be similar to 896mm!

CHG_CANON Loc: the Windy City

Actually, the official EOS T7i / EOS 800D Instruction Manual should be consulted for technical details, where the 1.4 I/II/III and EF 400 f/5.6L are documented as a Group H configuration (page 136). Group H is defined as supporting AF only via the center point (page 134).

amfoto1 Loc: San Jose, Calif. USA

Canon EF 1.4X III will work fine with the 400mm f/5.6 lens. In fact, to save a little, buy a used II version instead. I don't think there's much to be gained spending more for the III, with that older lens. The III teleconverters are optimized for use with some of the more recent "II" series lenses, in particular. You can probably save around $200 buying a used II, compared to buying a new III.

With T7i you'll be limited to using the center AF point only, I believe, using the 1.4X on an f/5.6 lens (where the effective aperture "becomes" f/8).

The 400mm with 1.4X will be a real bugger to try to get a steady shot, especially on a 24MP APS-C camera! It will "act like" almost 900mm..... and with no image stabilization... well, you might want a tripod or at least a monopod!

I doubt the EF 1.4X will even fit on that Sigma lens.... Or that the image quality of the combo would be worth a damn anyway. TCs generally work best with prime lenses instead of zooms.... And I'd expect a "do everything" 15X zoom that tries to cover wide to super telephoto focal lengths all-in-one to be especially bad with any TC added, since they usually don't have particularly good image quality to begin with. The 400mm, on the other hand, is quite sharp on its own, so will see little loss. I wouldn't even bother trying to use the TC on the 18-300mm. But all Canon TCs have a protruding front element that has to fit inside the rear barrel of the lens they are used upon, and I doubt the Sigma's is large enough diameter. Also, if the lens' rear elements move when focusing or zooming, there might be interference between that and the TC, possibly damaging one or both.

I don't have the Canon 400mm f/5.6 lens..... but I do use their 1.4X II and 2X II teleconverters on other lenses.

Here are some examples shot with Canon 300mm f/4 IS lenses without any teleconverter...



While these two were shot using the same lens with the 1.4X II teleconverter....



Hopefully even at Internet sizes and resolutions you can see that there's little effect on image quality adding the teleconverter. I expect the EF 400mm would be similarly good with 1.4X (though IS sure would be helpful!)

mwsilvers Loc: Central New Jersey

I didn't know the specifics for that particular lens, but I know the number of available focus points at f/8 varies by group. That's why I said up to 27 focal points. That technology is becoming so common on Canon bodies that I wonder if at some point the higher-end bodies will be able to autofocus at a maximum aperture level of f/11 so you could use a 2X Extender with a slow lens. It might have limited usefulness because of the amount of available light, but I'll bet there would be a bunch of people who would be thrilled.

jeep_daddy Loc: Prescott AZ

I don't know if you can rent one or not but you might want to try that first. I am 99% sure that this will NOT work on the Sigma lens since it's a f/6.3 lens. But it will work on the Canon 400mm lens and when you install the teleconverter is will become an f/8 lens. This can cause your shutter speeds to be somewhat slow and or cause you to increase your ISO which will introduce noise in your pictures. That's why I say it's best to try one first. Or buy one from a store that has a 30 day return policy so you can buy and try.

Notorious T.O.D. Loc: Harrisburg, North Carolina

Check out some of Arthur Morris' YouTube videos on using Canon Extenders. Very good results with most of the longer Canon lenses...

Best,
Todd Ferguson

imagemeister Loc: mid east Florida

I never knew the T7i was capable of AF at f8 ! - Apparently, it has the same focus system as the 80D ! ?

I have the 80D and the 400 prime with 1.4X II. It is my understanding, that ( because of it's age) using the 400 prime can only give you center point AF - no matter which extender or body you use - so no advantage for the III series extender regarding AF with the 400 prime. There may be an optical advantage for using the III series extender - but is it $200-250 better than using a used II series - IMO NO.....but if spending the extra for the III series makes you sleep better at night - go for it

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