Anyone ever successfully use a teleconvertor with unsupported lenses?

[misterjones]

So, I'm on a bit of a budget and can't really afford to buy lenses in the 400-600mm range like I want. Found out about Canon and Tamron's 1.4 and 2x teleconverters and figured it might be a cheap way to get extra range out of my current lenses. However, looking at both, they only support using their respective higher end long prime lenses and maybe a handful of zoom lenses, none of which I own. So I'm wondering: can these teleconverters be used with unsupported lenses with decent results or can they just not be used all together.

 

[Rickbb]

Usually, unsupported means no autofocus, exposure, indexing, etc. You'd have to do everything manually. Maybe even open up the F stop all the way to focus then back down to get the exposure right.

It all depends on your current lenses, age, FF or APC, etc.

 

[KJ_North]

Like mentioned above, you will lose autofocus etc. Also likely you will compromise the image quality below where you would like. I use a 1.4X on the RF100-400 but it supports that convertor. I likely lose some image quality but i accept the loss to get the extended reach.

So in summary you will...
* Lose some image sharpness
* Also be one F stop higher with a 1.4X or 2 stops higher on a 2X convertor. This means your ISO will be much higher.
* Autofocus will not work on your camera with either convertor.

 

[RAZKY]

So, I'm on a bit of a budget and can't really afford to buy lenses in the 400-600mm range like I want. Found out about Canon and Tamron's 1.4 and 2x teleconverters and figured it might be a cheap way to get extra range out of my current lenses. However, looking at both, they only support using their respective higher end long prime lenses and maybe a handful of zoom lenses, none of which I own. So I'm wondering: can these teleconverters be used with unsupported lenses with decent results or can they just not be used all together.

Any teleconverter that physically fits the camera and lens can be used, though you may lose some functions. Generally teleconverters produce the best results with fast primes and a few high-end zooms – they don’t play well with most other lenses. There are always exceptions, of course, and it may be worth your while to try some combinations. Much depends upon how much image quality you want. I would buy from a reputable second-hand dealer, with a good return policy - there’s always the possibility of a pleasant surprise.

 

[misterjones]

Thanks for all of your answers. I'm going to take it all into consideration and figure out my next steps. I really need to replace my Canon 75-300 kit lens with something nicer first.

 

[Golem]

I disagree with everything above. "Unsupported" is not really about metering or AF. If the TC actually fits without damaging glass due to collision, the elecronics very likely will be no problem. But no problem or big problem, the electronics hardly matter if the optics are actually the worst problem.

The very WORST version of "unsupported" would be glass damaged by collision.

A less worse version is an optical mismatch. Dedicated TCs are optically formulated to "play nicely" with the formulas of certain lenses. A mismatch is an ad hoc reformulation of the overall optical package. Imagine if you disassembled one of your lenses and faced an element in the wrong direction during reassembly. Bad news.

Better than fitting a dedicated TC onto a lens outside its "family" would be a broadly general purpose TC. These are formulated to do a pretty decent job with typical mid-long lenses. Its assumed you wont use it wide open with critical expectations. A non-specific tool will do a better all around job than a very specific tool applied contrary to its specifications.

TCs are really a relic of the film era. Are there pix you cant take with your current lenses, and you cannot acquire a longer lens ? News flash: There will ALWAYS be pix you cant take ... and dishes you cant cook, and sports you cant play, and etc etc. Choose your battles.

 

[KJ_North]

"TCs are really a relic of the film era."

Sorry i have to disagree with that statement. They serve a purpose, many of us have limited funds and cant afford primary zoom lens to extend reach etc. I use a 1.4X it works great and gives me a little extra reach which comes in handy many times. If they were relics from the film era they wouldn't still be updating them and making newer versions.

 

[Rich_A]

I've had some luck with a Nikon TC-17E (1.7x) and an unsupported older Nikkor AF-S 300m f/4 ED. As noted above, if it fits, it'll work. Image degradation will be minimized with a 1.4 or 1.7 rather than a 2x. Auto-focus issues occur when enough light isn't available for the AF system to work. The TC-17E spec. requires a max. aperture of f/2.8 but in bright light, I can get it to work with my f/4. Maybe I'm a bit odd, but no auto-focus isn't the end of the world unless you're shooting fast moving objects, though there's a lot more at play than just auto-focus here.

Or turn the problem around. A Cannon APS-C using your 75-300mm lens will automatically give you a 486mm lens (1.62x crop factor). Maybe purchasing a body will be less expensive than a lens. And if the sensor resolution is higher than your current body, you could crop the images yet retain the same resolution as your current body giving you yet another bump in effective focal length. And, you haven't affected the resolution of the lens system!

Here's another thought; have you considered purchasing used equipment? There's an awful lot of great stuff out there you can pick up at a discount.

 

[Golem]

Sorry i have to disagree with that statement. They serve a purpose, many of us have limited funds and cant afford primary zoom lens to extend reach etc. I use a 1.4X it works great and gives me a little extra reach which comes in handy many times. If they were relics from the film era they wouldn't still be updating them and making newer versions.

Those updatings confirm that TCs are relics.

 

[petrochemist]

Teleconverters vary hugely. Old film era TCs are generally usable with any lens, but the worst of these couldn't compete with simple cropping when tried on my first 6MP DSLR, & today's higher resolution cameras can handle cropping better than that old beast.

Many of today's TC's protrude into the rear of the lens body so only work on a small number of lenses, which don't have a restriction/rear element in the region. Quality of these are typically very high - they are often used by professional wildlife photographers.

My teleconverters are all film era models (most not giving AF or aperture communications) but some have useful features such as a built in macro focusing helicoid. Unlike going for a lens with a longer focal length adding a TC doesn't normally increase the minimum focusing distance, with these models MFD can be reduced. Another TC I have actually adds AF to manual lenses...

Despite collecting loads of TC's I only use them fairly rarely (mainly when I want reduce MFD or to reduce the wight of lenses carried). A better solution for the budget conscious is probably to look at adapting old lenses of a different mount. For long lenses (with AF) I use minolta A series lenses on my Sony E mount body, as well as various manual focus options (upto 1000mm) these have all been less than 1/10 the cost of comparable focal length native lenses. There are quite a few affordable options available for EOS if your willing to focus old glass manually.

 

[davev]

I'm going to suggest that you go in a different direction.
If you're still using the XSI, buy a new camera with more megapixels.
That camera is a 12mp, move up to a used 70D (20mp) or an 80D (24mp)
You'll be putting more pixels on your subject, the focusing system will be better, you'll have more frame/second, and higher iso's will be cleaner.

I've bought from KEH a few times, you get a six month warranty, and so far, everything I've bought from there is still working years later.

A used 70D is between $300 and $350, a used 80D is around $450.

 

[zombiesniper]

To the OP.
The 75-300 may work with a 1.4x TC but will be near unusable with a 2x.
300mm is not a bad focal length but not knowing what you need the extra focal length for it's hard to really make a recommendation.

I disagree with everything above. "Unsupported" is not really about metering or AF. If the TC actually fits without damaging glass due to collision, the elecronics very likely will be no problem. But no problem or big problem, the electronics hardly matter if the optics are actually the worst problem.

The very WORST version of "unsupported" would be glass damaged by collision.

A less worse version is an optical mismatch. Dedicated TCs are optically formulated to "play nicely" with the formulas of certain lenses. A mismatch is an ad hoc reformulation of the overall optical package. Imagine if you disassembled one of your lenses and faced an element in the wrong direction during reassembly. Bad news.

Better than fitting a dedicated TC onto a lens outside its "family" would be a broadly general purpose TC. These are formulated to do a pretty decent job with typical mid-long lenses. Its assumed you wont use it wide open with critical expectations. A non-specific tool will do a better all around job than a very specific tool applied contrary to its specifications.

TCs are really a relic of the film era. Are there pix you cant take with your current lenses, and you cannot acquire a longer lens ? News flash: There will ALWAYS be pix you cant take ... and dishes you cant cook, and sports you cant play, and etc etc. Choose your battles.

Yes the optical collision is a factor when TC's are used with lenses that are not physically compatible. Glass damage? The user would have to be a special kind of moron to actually damage the glass in this situation. At worst you would be out several hundred dollars for something you can't use.

Those updatings confirm that TCs are relics.

What?
Things that we've updated. Cameras, lenses, cars, TV's, etc.
TC's are still made new to this very day for almost everyone one of those new cameras that were NEVER designed for film.

 

[Scott Whaley]

Like mentioned above, you will lose autofocus etc. Also likely you will compromise the image quality below where you would like. I use a 1.4X on the RF100-400 but it supports that convertor. I likely lose some image quality but i accept the loss to get the extended reach.

So in summary you will...
* Lose some image sharpness
* Also be one F stop higher with a 1.4X or 2 stops higher on a 2X convertor. This means your ISO will be much higher.
* Autofocus will not work on your camera with either convertor.

I have found that the auto focus will work when using the live view mode on the canon cameras. It will not work while looking through the view finder. The problem with using a teleconverter is that the teleconverter has a extension section which will be inserted into the lens. If you lens does not have enough room for the extension to fit, then it will not match up. We have an older Canon 100-400 lens and my 2X extension will only allow it to go down to 300. It will not retract below that. So that is another issue with the extension. I do have two 150-600 Sigma lenses which work just fine with the teleconverter. The auto focus issue only happens with the DLSR cameras. My R5 mirrorless camera does auto focus through the view finder.

 

[zombiesniper]

Interesting auto focus issue. I have never seen this before. Mine works fine although I’m using a lens that the TC was designed for.

 

[petrochemist]

Interesting auto focus issue. I have never seen this before. Mine works fine although I’m using a lens that the TC was designed for.

Phase detect AF can often have a problem if the TC makes the effective aperture too small. Shooting in live view many cameras use contrast detect AF which doesn't have the same issue.

Lenses listed as being compatible with TCs will take the aperture reduction into account.
2x TCs reduce aperture by 2 stops (not a problem on a f.2,8 lens, but starting to cause issues on a f5.6 lens)
1.4x TCs only have an aperture loss of 1 stop so are more tolerant.
I don't know of any modern TCs that are 3x but I've met film ones of this grade that cost 3 stops (never seen one that supports AF)