Kenko Extenders 1.4x and 2x

Hey everyone, I was considering buying one of these, but I heard something...

These aren't compatible with EF-s lenses? That would be a great let-down for me.

If so, I might sell my 55-250mm and get a 70-300mm EF lens.

Thanks!

just a heads up, if you want to keep autofocus working you need a lens with constant aperture of 4 for the 1.4x and 2.8 for the 2x

Warl0rd wrote in post #9292338
just a heads up, if you want to keep autofocus working you need a lens with constant aperture of 4 for the 1.4x and 2.8 for the 2x

just a heads up...AF works on the 1.4 TC and 70-300mm if you are maxed out at 300mm with the TC using center point it will hunt though, back it off, and it's fine...also the outer points work fine when at 300mm...

but yeah, just cause the lens is a f5.6 doesn't mean you always lose autofocus

would i use it to shoot sports or anything no...but a bird in a tree works fine...

They are not compatible with EF-S. But if you use an extender you can get them to work. Probably not a good combo though.

jgatti wrote in post #9292375
The ones I have are compatible with EF-S. I have both the 1.4x and 2x Kenkos.

really?...they work with your 55-250mm IS?...that's the first i've ever heard...i wonder if there's a new model out...that'd be great for all those 55-250mm owners

ah...too quick...saw your edit

Sorry, I tried to edit quick before anybody read that. I got the macro tubes and teleconverters at the same time and I mixed them up in my brain. The macro tubes are compatible with EF-S but the teleconverters are not. But I can get the TC's to work when using the macro tubes, but it's not a desirable combo.

There is one that is compatable with many EF-S lenses and allows AF to work at f/8 and above on all the EOS bodies.

Kenko Pro 300 DG 2X or 1.4x (not DGX)

Here's my big post about it:

https://photography-on-the.net/forum/showthre​ad.php?t=802142

My 2x tele and 70-200 f/4 AutoFocus works (Video and Photos)

AutoFocused Sample with TC @ 400mm from Canon 70-200 F/4 on Canon 5D

Full Image JPG Convert

3 Pin TAPE PHOTO : EXPAND IMAGE TO SEE TAPE ON TC PINS ON BOTTOM RIGHT:

HTTP response: 404 | MIME changed to 'text/html' | Byte size: ZERO

DreDaze wrote in post #9292364
just a heads up...AF works on the 1.4 TC and 70-300mm if you are maxed out at 300mm with the TC using center point it will hunt though, back it off, and it's fine...also the outer points work fine when at 300mm...

but yeah, just cause the lens is a f5.6 doesn't mean you always lose autofocus

would i use it to shoot sports or anything no...but a bird in a tree works fine...

I'm just saying what both kenko and canon say regarding extenders. canon says their 1.4x isn't even compatible with the 70-300 IS.
i don't have them to make my own tests.
AF will work fine at f/8 on a 1D(s) body aswell, its all a matter of how good you AF system is. don't forget the central point of the 40D is extra sensible, but not on the OP 1000D. in the end it depends on the lighting if its sunny and the lens is in a tripod and there is enough contrast, I bet the 2x will also work

crowflyawa wrote in post #9292519
There is one that is compatable with many EF-S lenses and allows AF to work at f/8 and above on all the EOS bodies.

Kenko Pro 300 DG 2X or 1.4x (not DGX)

Here's my big post about it:

https://photography-on-the.net/forum/showthre​ad.php?t=802142

My 2x tele and 70-200 f/4 AutoFocus works (Video and Photos)

read your post...didn't see where you attached an EF-S lens to the TC...

also did you try it on all the eos bodies?...if not seems bold to say it would work for all...

i have the kenko 1.4x DG...and i know that does not mount to the two EF-S lenses i tried, 18-55mm IS, and 55-250mm IS

Hmm that's a pity. Are there any teleconverters for EF-s that are mentionable?

Some, EF-S lenses fit and some do not.
the Kenko has it's elements the most recessed of all TC's I know of and therefore has the most computability potential.

There are a few websites who have tried a few EFS lenses on them with mixed results, some work some don’t.

The statements I made about all EOS bodies is generally correct.
I'll link you to canon's docs if you prefer to not take my word for it.

The 1D series can use a 2x TC with AF up to f/8
The 5D, 7D, 50D can use 2x TC with AF up to f/5.6
EOS 3 (film) bodies have a similar spec.

With taped pins the Kenko Pro 300 DG becomes non reporting to the body so it does not know the f/4 lens x 2 = f/8 and the 5D body will try to AF and succeed fine.
It is a firmware limitation only, and the taped pins trick bypasses it.

-Steve

yes, but the 5D AF system is way more accurate and sensible then an entry level camera, lest say the OP 1000D.

Its hard to guess it will work on all bodies just because it works on a High-end camera.

I have an old MF lens with aperture ring which I use on a AF confirm adapter, so the camera has no idea what is the aperture set manually on the lens. I can get the AF confirm on all aperture up to f/8, at f/8 it simply stops working, not even the central point. so its not a mather of electronic contacts but rather a physical limitation of the AF sensor on this body.

crowflyawa wrote in post #9292918
Some, EF-S lenses fit and some do not.
the Kenko has it's elements the most recessed of all TC's I know of and therefore has the most computability potential.

There are a few websites who have tried a few EFS lenses on them with mixed results, some work some don’t.

The statements I made about all EOS bodies is generally correct.
I'll link you to canon's docs if you prefer to not take my word for it.

The 1D series can use a 2x TC with AF up to f/8
The 5D, 7D, 50D can use 2x TC with AF up to f/5.6
EOS 3 (film) bodies have a similar spec.

With taped pins the Kenko Pro 300 DG becomes non reporting to the body so it does not know the f/4 lens x 2 = f/8 and the 5D body will try to AF and succeed fine.
It is a firmware limitation only, and the taped pins trick bypasses it.

-Steve

do you have any links to the sites that mention using the TC's on EF-S lenses...as this is the first i've ever heard of it...

also did you try the lenses and TC without the tape trick?

the kenko 1.4X doesn't report anyways...so it would seem like the tape may be unneccesary...(edit: wait i think it doesn't report for me, because my lenses aren't L, and don't have those 3 contacts)

and yes they'll all AF at those apertures...i know that...i was more referring to your 70-200 f4L and a 2X...i don't know if that'd focus with all eos bodies

Your TC may not work but I think you are about the Rebel 450D bodies is a physical AF issue, it is only a firmware limit.
The firmware is set to disable any AF for any lens if it detects a TC and f/8 result on lens. Your "non reporting" TC has typical results with MOST TC's in the world.

That's why I name the model of mine specifically since it is known to work with AF with the 3 pins taped.

I have a 5D and it works.
I have a Rebel XSI 450D and it works too
with this Kenko 300 DG 2x TC and these lenses AF works at f/8 fine on all AF points, the Center is best of course.

I can’t comment on the 1000D though I have never used or tried it and have not seen any info from canon on it yet.

This model of Kenko TC is a reporting model, taping the 3 pins disables reporing in a way that tricks the Canon body firmware to allow AF to operate fine.
This TC without the tape some lenses will not AF that will when taped, the 70-200 f/4 is an example.

-Steve

Warl0rd wrote in post #9292979
yes, but the 5D AF system is way more accurate and sensible then an entry level camera, lest say the OP 1000D.

Its hard to guess it will work on all bodies just because it works on a High-end camera.

I have an old MF lens with aperture ring which I use on a AF confirm adapter, so the camera has no idea what is the aperture set manually on the lens. I can get the AF confirm on all aperture up to f/8, at f/8 it simply stops working, not even the central point. so its not a mather of electronic contacts but rather a physical limitation of the AF sensor on this body.

The firmware on EOS bodies, except the 1D series, is set to disable any AF for any lens if it detects a TC and f/8 result on lens. Your "non reporting" TC has typical results with MOST TC's in the world.

That's why I name the model of mine specifically since it is known to work with AF with the 3 pins taped.

With this Kenko 300 DG 2x TC and these lenses AF works at f/8 fine on all AF points, the Center is best of course.

I'll look up some links from my bookmarks for ya on the EFS TC lens combo.

Compability:

Check the maximum aperture (F Value) of your prime lens to ensure the Teleplus will operate in AF mode. If the lens is slower than required F value (as specified below), the lens/Teleplus combination will operate in the MF mode.

As you know , the genuine Canon EF lenses are divided into two types, those with 7 connecting pins and with 10 pins. The general lenses in black are using 7 pins and the most telephoto lenses in white are using 10 pins except the EF35-350mm F3.5-5.6L USM and EF70-200mm F2.8L USM which have 7 pins.

Lens with 7 pins + 2x TC

EOS 3 F 5.6
EOS F 4

Lens with 10 pins + 2x TC
EOS 3 F 4
EOS F 2.8

When using the Teleplus Pro300DG 2.0x with Canon EF lens with 10pins, the coupling fuction is the same as the genuine Canon Extender EF2.0x.

Therefore, if the prime lens is slower than above mentioned maximum F value, the elecctrical AF function will be automatically cut and shifted to MF mode.

As you know, the genuine Canon EF lenses are divided into two types, those with 7 connecting pins and with 10 pins. The general lenses in black are using 7 pins and the most telephoto lenses in white are using 10 pins, except the EF 35-350mm F3.5-5.6L USM and EF 70-200mm F2.8L USM which have 7 pins.

From the Canon description of the 5D:

http://www.canon.com …report/200509/r​eport.html

"With its new nine-point AF sensor with six Assist AF points (See Photo 4), the EOS 5D focuses quickly and precisely. Nine focusing points (AF points) are displayed in the viewfinder (Fig. 4). The center AF frame has a cross-type sensor with a highly sensitive vertical line-sensor working at f/2.8 and a horizontal line-sensitive sensor working at f/5.6 with a base length twice as long as previous models. This delivers improvement in both tracking and precision."

"Also six Assist AF points (two points for f/2.8 and four points for f/5.6, all invisible) (Fig. 4) are located for intensive measurement in the center area. The six points together with the nine points deliver fifteen-point AF in the AI servo AF mode for automatic AF point selection, dramatically enhancing the performance in tracking."

You can look up the same specs on any canon body you are interested in, if you need assistance finding it let me know the model body and I'll try.

-Steve

DreDaze wrote in post #9293019
do you have any links to the sites that mention using the TC's on EF-S lenses...as this is the first i've ever heard of it...

also did you try the lenses and TC without the tape trick?

the kenko doesn't report anyways...so it would seem like the tape may be unneccesary...

and yes they'll all AF at those aprertures...i know that...i was more referring to your 70-200 f4L and a 2X...i don't know if that'd focus with all eos bodies