Extender EF 1.4x III won't fit on EF-S 18-55 or EF 75-300

[sncamp7957]

I have a model EOS Rebel T3 camera kit with 18 - 55 EFS and 75 - 300 EF lenses.  I purchased a Canon EF 1.4 X III lens extender.  It fits on my camera body but does not physically fit up to either EF or EFS lenses listed above.  I figured since it is an EF extender it should work with my lenses.  What options would I have now for a compatible extender?

Is there a lens extender that will work with my Rebel kit?

[kvbarkley]

Here are the compatible lenses

But really, your telephoto is not a good enough lens to benefit from an extender.

[kvbarkley]

That said, I have a Tamron extender that works with any lens. I keep forgetting about it, because I found that it really does not add that much. Bob Atkins found that upsizing vs TC was pretty much a wash

https://www.bobatkins.com/photography/reviews/canon_EF_70-300_II.html

[johnrmoyer]

I disagree with Bob Atkins. There are tradeoffs, but the conclusion depends upon financial budget and weight budget.

Greater magnification from using the extender results in more data being collected. More pixels on the subject is always better than enlargement by interpolation. The extender costs less and weighs less than a high quality long focal length lens. Enlargement by interpolation may still be done after using an extender.

Disadvantages to using an extender include:

• smaller aperture so in some cases more small aperture diffraction blur
• less contrast for small features
• additional lens elements may add distortion or color fringes in some cases
• the image quality is not as good as a much more expensive high quality long focal length lens

For a Canon lens with a third party extender, Canon DPP digital lens optimizer may be used to remove some of the small aperture diffraction blur mitigating that disadvantage. Unsharp mask may be used to mitigate the loss of contrast for small detail. Both of these are superior to using interpolation for upsizing.

https://www.rsok.com/~jrm/2017Feb07_birds_and_cats/2017feb01_cardinal_IMG_0929.html

https://www.rsok.com/~jrm/2022Oct07_birds_and_cats/2022oct05_monarch_IMG_0672c.html

https://www.rsok.com/~jrm/2021Sep08_birds_and_cats/2021sep02_bumblebee_IMG_3837c.html

A Bumble Bee (Bombus pensylvanicus) was on a Zinnia in Norman, Oklahoma, United States on September 2, 2021. I made this photo with a very old lens as an experiment. I purchased the lens in 2011 and nearly wore it out. For this photo, it was attached to a newer camera body with an adapter with two telephoto extenders. 700.0 mm ; Canon EF-S 55-250mm f/4-5.6 IS ; Kenko TELEPLUS HD C-AF 2X DGX ; Vivitar SERIES 1 1.4X AF

[sncamp7957]

Ok, so what would be a recommended "better" lens than my EF 75-300?   And of course fit my EF or EFS body mounting.

[kvbarkley]

For a similar focal length, Canon's EF 70-300 II is a good lens.

For longer reach, the Sigma or Tamron 150-600's are generally recommended around here. I have the Tamron.

I have the 70-300 II, which I pretty much always have with me, and carry along the Tamron 150-600 when I know I will need a "big gun" like for birds and wildlife.

[shadowsports]

@kvbarkley this is great info.  I have a sigma TC, but am not sure if it works with other lenses.  Its similar in design to Canon's 1.4x and only appears to support longer FL's.  

@sncamp7957,

I think you have a decision to make.  Unless you plan on buying one of the lenses listed above, the Canon extender is worthless to you.  I hope you can return it.  Otherwise, you have a very expensive desk ornament. 

 Lenses are the real investment in photography and there is no replacement for buying higher quality lenses with longer native focal lengths.  Extenders can work decently in some situations, but in general, we'd recommend buying longer lens if possible, or a lens that can still perform well enough "extended".  When you use an extender, a lens loses some of it light gathering capability, and can also lose AF capability above certain apertures (some cases)  These things need to be considered.

If you plan to purchase another DSLR body and lenses, then the adapter may have value.  Your T3 is now 13 yrs old.  If you think you might move to mirrorless, I would investigate returning the adapter.