-=FAQ=- Teleconverter/T-Con Tele extender Discussion

I used to own the 350D and Kenko 1.4x PRO DG, and never had a problem...

I've not seen this (pins and the operation with lenses) mentioned clearly so will do so here...

The front of the TC is the part that contains the pins that tells a lens to report the true aperture/focal length. So for those pins to have any effect the lens must also have the additional pins.

There is also a quirk that at least exists with the Kenko Pro 300 DG model TC and at least the one Sigma lens that I own (and I've seen it mentioned for other Sigma lenses). This lens does have the extra pins, as does the TC, so should report the true FL/aperture etc. And they do, assuming you put the TC on the lens and then mount the combo on the camera. Doing so in the opposite order - mounting the TC to the camera and then the lens to the TC makes it behave as if the TC is not there.

Some examples with a Kenko Pro 300DG:
- Tamron 28-75 does not have the extra pins, so camera does not know the TC is even there
- Canon 400mm F/5.6 does have the extra pins, and regardless of mounting order will always report the TC there (unless you tape the pins)
- Sigma 150mm F/2.8 does have the extra pins, if mounting in the documented order (lens to TC, then TC to camera) the TC is known to be there, if mounting in the "wrong" order (TC to camera, then lens to TC) the camera does not know the TC is there

Hope this at least helps someone.

I just mounted a 40D camera on a tripod under indoor lighting conditions, set IS0 400, mounted a Canon 100mm f/2 lens...this does not have extra pins. Meter reading was 1/60 f/2.

Next I mounted a Kenko Pro DG 1.4x convertor, which has the pins to report its presence. In combination with the Canon 100mm f/2, the camera still believed the lens had f/2 available as max aperture, since the lens lacked the three pins needed for the camera to detect the Kenko. The meter showed 1/60 f/2 reading, but (in manual) it reported that exposure was -1EV with that combination. The camera was fooled about max aperture available, but its meter was not fooled about the reduction in light due to the change of FL due to the telextender. By changing shutter speed to 1/30 at f/2, the meter now indicated correct exposure. Working as one would expect!

Question;

I have a Canon TS-E17 f/4 L tilt/shift lens and have heard that it is compatible with certain T-cons but am looking to find out if it will work with the Canon EF1.4 EXII T-con as that seems to be a good quality T-con and I would be willing to pay the price premium for one if it works.

Also, the manual for the lens says this lens is not compatible with it and if it is, I am curious to know why Canon is saying the opposite?

Any help on this would be much appreciated.

Cheers!

The Canon 1.4x-II has a front element which sticks out in front of the lens mount which mates to the primary lens. It will not fit the Canon 100mm f/2 lens as a result, whereas the Kenko 1.4x DG will fit the Canon 100 f/2 lens. One example of the physical incompatibility which has to be considered, not merely optical suitability. Not having seen a 17mm TSE for real, I have no way of knowing with certainty what physical incompatibility might exist, but with a 17mm FL I would be extremely surprised if it would be able to accept the Canon 1.4x convertor when the 100mm cannot!

Here is the official list of lenses compatible with the Canon 1.4x-II teleconvertor...
EF 100-400mm f/4.5-5.6L IS USM

EF 135mm f/2L USM

EF 180mm f/3.5L Macro USM

EF 200 F/1.8 L USM

EF 200mm f/2.8L II USM

EF 200mm f/2L IS USM

EF 300 F/2.8 L USM

EF 300mm f/2.8L IS USM

EF 300mm f/4L IS USM

EF 400mm f/2.8L IS USM

EF 400mm f/4 DO IS USM

EF 400mm f/5.6L USM

EF 500mm f/4L IS USM

EF 600mm f/4L IS USM

EF 70-200mm f/2.8L IS USM

EF 70-200mm f/2.8L USM

EF 70-200mm f/4L IS USM

EF 70-200mm f/4L USM

EF 800mm f/5.6L IS USM

Wilt wrote in post #10144140
The Canon 1.4x-II has a front element which sticks out in front of the lens mount which mates to the primary lens. It will not fit the Canon 100mm f/2 lens as a result, whereas the Kenko 1.4x DG will fit the Canon 100 f/2 lens. One example of the physical incompatibility which has to be considered, not merely optical suitability. Not having seen a 17mm TSE for real, I have no way of knowing with certainty what physical incompatibility might exist, but with a 17mm FL I would be extremely surprised if it would be able to accept the Canon 1.4x convertor when the 100mm cannot!

Here is the official list of lenses compatible with the Canon 1.4x-II teleconvertor...
EF 100-400mm f/4.5-5.6L IS USM

EF 135mm f/2L USM

EF 180mm f/3.5L Macro USM

EF 200 F/1.8 L USM

EF 200mm f/2.8L II USM

EF 200mm f/2L IS USM

EF 300 F/2.8 L USM

EF 300mm f/2.8L IS USM

EF 300mm f/4L IS USM

EF 400mm f/2.8L IS USM

EF 400mm f/4 DO IS USM

EF 400mm f/5.6L USM

EF 500mm f/4L IS USM

EF 600mm f/4L IS USM

EF 70-200mm f/2.8L IS USM

EF 70-200mm f/2.8L USM

EF 70-200mm f/4L IS USM

EF 70-200mm f/4L USM

EF 800mm f/5.6L IS USM

Thanks for that!

I have read from other forum members here that the Canon EF 1.4 EX II will in fact fit inside and that only a slight loss in sharpness will be realized, though I have yet to find out if all of the lens' physical attributes can still be used without detrimental effect; most specifically, the shift function and light fall off characteristics on the edges of the image. Hopefully, I'll hear back from them shortly about that specific issue.

As far as the mounting depth issue goes, the T-con protrudes approx. 10 mm inside of the lens and the TS-E17 has about 19mm of clearance, which is more then the 100L macro and why it will fit without damaging anything.

So the question remains, why does Canon say it's not compatible?

Cheers!

Just as a quick informational update, I picked up a Canon EF 1.4 x II today to use on my TS-E17 f/4 L and it fits with no problems and works like a charm!

The only oddity is that the exif data doesn't show the extender being there and the aperture setting of the camera remain unaffected by it being installed but otherwise works well and gives my lens some added flexibility now!

The Ghost of FM wrote in post #10169851
Just as a quick informational update, I picked up a Canon EF 1.4 x II today to use on my TS-E17 f/4 L and it fits with no problems and works like a charm!

The only oddity is that the exif data doesn't show the extender being there and the aperture setting of the camera remain unaffected by it being installed but otherwise works well and gives my lens some added flexibility now!
!

Look at the pin configuration of the TSE...does it have 5+3, or does it have 8+3? 5+3 will not report thru the 1.4x-II, but 8+3 does.

Wilt wrote in post #10170447
Look at the pin configuration of the TSE...does it have 5+3, or does it have 8+3? 5+3 will not report thru the 1.4x-II, but 8+3 does.

The 17 has a 5 + 2 pin configuration.

I would attribute this to the lens being a manual focus only design.

Focus confirmation does though still occur as it does without the extender attached...no change there, which is good!

Essentially, it's really just the loss of reporting and a very slight loss in overall sharpness, which was expected and manageable. At this point, I'm going to assume that Canon doesn't list this lens as compatible strictly based on the loss of exif data reporting the converter present.

Cheers!

The Ghost of FM wrote in post #10170610
At this point, I'm going to assume that Canon doesn't list this lens as compatible strictly based on the loss of exif data reporting the converter present.

They don't list any shorter lenses, the short end of the 70-200 being the shortest. I'd be curious to hear whether any of the shorter lenses have the additional pins - I suspect not.

Even my 85/1.8 doesn't have the pins. I would think that lens would be a natural candidate for being used with a TC. Certainly I've used mine with a Kenko 1.4X to get me a lightweight and discrete 120mm f/2.5 lens rather than lug around my 70-200 all the time. I was very shocked and surprised when the EXIF came back unmodified. It took me a few moments to discover why. Stupid lens!

I think it is fair enough to not expect people to be fitting TCs onto wide angle lenses. That probably would be seen in most cases as illogical.

tdodd wrote in post #10171877
I think it is fair enough to not expect people to be fitting TCs onto wide angle lenses. That probably would be seen in most cases as illogical.

With a standard UWA, yes, it would seem illogical but with a tilt shift lens, the extender can come in handy in situations where the subject is better suited by a slightly longer focal length and requires the adjustment possibilities of a TS lens.

Cheers!

I agree with you. My get out was the very deliberate use of the phrase "most cases". The unstated implication was that TS lenses would fall into the "other cases" category.

i was unable to find the info on this...

does anyone know if i can fit (and use) either of the following two tele converters on a Canon EF 50mm f/1.8?

Kenko Teleplus PRO 300 DG 1.4x AF
Tamron 1.4x SP AF Pro

Both should fit AFAIK. I have the Kenko, can't find a lens it doesn't fit (I think the only ones it wont fit is EF-S lenses). Even fits my ultra-wide. I'm fairly sure the Tamron will be the same, in fact some of the Kenko and Tamron TCs look like they're identical units with a different name stamped on them.