Lens extender - question

[Brett Culp]

Hi all,

There are rare occasions when need a long lens for my t2i, something in the 200mm range. I am mainly using primes, & I don’t really want to tote around a 200mm prime that I will rarely use since I travel frequently.

I am wondering if there is a 1.4x or 2x lens extender I can use for my vintage Nikon 135mm f/2 lens.

Is there an extender that will work on this lens on a Canon t2i body? If so, how will it affect the speed of the lens?

I realize it’s not a perfect solution, but is it an option with a vintage, non-Canon lens?

Thanks,
Brett

[James Donnelly]

There are plenty of extenders out there. If you can afford the canon ones, great. Otherwise, you may have to settle for something like a Kenko Pro or such like.

You will lose 1 stop of light with a 1.4x extender and 2 stops for a 2x extender. You will likely lose some sharpness and introduce some chromatic aberration.

I would be cautious. In terms of actual resolution of images via extenders, it's often a better bet to simply zoom digitally in post. You'll have to experiment with whatever tools you can get your hands on. Try cropping the video in your NLE from shooting without the extender, and compare this to footage with the extender on. You might be surprised.

[Brett Culp]

Hi James,

Thanks for your quick reply.

The specs on the Canon extenders include a list of Canon lenses that the extenders will work with. In reality, will the extender work with any long lens with a Canon mount?

Also, when a f/2 lens loses 1-stop, does it go to f/2.8 or f/3.0?

[James Donnelly]

Generally, EF compatible extenders work with EF lenses, but there can be complications.

Also, EF-S lenses may not work with EF extenders.

f/2 -> f/2.8 is one stop (half the light)

[Andy Wilkinson]

Brett,

The Canon extenders are a wise buy and very useful if you need the occasional reach like me. However, I'd strongly recommend the 1.4X over the 2X. I found the 2X gave very much worse image compromises (more light loss as mentioned, but much worse CA and image softening), especially noticeable when used with the fastest and sharpest Canon zooms (70-200mm IS F2.8 and 70-200 IS F4) with my 7D whereas the 1.4X was much better/at times hardly noticeable/very acceptable. To me (and bear in mind I need razor sharp stills as well as video capability) the Canon 1.4X is the one to have, the 2X being a stretch too far (in every way, not just reach!)

Also, bear in mind you won't want to/can't use an extender on anything less than about 50mm focal length.

There are some great reviews of both the Canon extenders out there on first rate photographic sites - well worth a Google - and if you have the correct adapter ring for Nikon lenses they should work in the EXACT same way as when those lenses are mounted (via that adapter) directly onto the T2i, i.e. the lens and the camera "won't know" that there is an extender between them (except for light loss, change in effective focal length and some image quality loss of course!). Hope this makes sense/is useful.

[Brett Culp]

Thanks Andy & James!