Quick lens question: I am looking at getting a Sigma 70-300mm F4-5.6 DG OS lens for my Canon T7. Does anyone know if there is a lens extender that will fit this lens. It is not a deal...

3kids3cats Loc: Johnston County, North Carolina

I am looking at getting a Sigma 70-300mm F4-5.6 DG OS lens for my Canon T7. Does anyone know if there is a lens extender that will fit this lens. It is not a deal breaker, but just something I would like to get if possible. I have read online that a few years ago, no lens extenders would work on 70/300 lenses, but then I also read that with firmware updates and all, that they do now.
Can someone let me know what is what?
TIA

CHG_CANON Loc: the Windy City

Canon extenders will not work with any lenses except compatible Canon lenses. Even if a Sony extender, or other third-party options, would physically attach to the Sony lens, you still probably have a problem of losing autofocus on an EOS T7. Check your manual and see if that DSLR model is limited to f/5.6 max aperture configurations.

brentrh Loc: Deltona, FL

Never been satisfied with lens extenders. Canon extenders for big lenses seem to be excellent those lenses are out of my affordability. I use what I have cropping in post processing can produce satisfying results.

3kids3cats Loc: Johnston County, North Carolina

CHG_CANON wrote:

Canon extenders will not work with any lenses except compatible Canon lenses. Even if a Sony extender, or other third-party options, would physically attach to the Sony lens, you still probably have a problem of losing autofocus on an EOS T7. Check your manual and see if that DSLR model is limited to f/5.6 max aperture configurations.

Okie doke. Like i say, its just something I was thinking about to get longer distance without breaking my bank. I will not consider them then.thanks

robertjerl Loc: Corona, California

3kids3cats wrote:

I am looking at getting a Sigma 70-300mm F4-5.6 DG OS lens for my Canon T7. Does anyone know if there is a lens extender that will fit this lens. It is not a deal breaker, but just something I would like to get if possible. I have read online that a few years ago, no lens extenders would work on 70/300 lenses, but then I also read that with firmware updates and all, that they do now.
Can someone let me know what is what?
TIA

Sigma compatibility charts show the 70-300 having autofocus with all three types of telexteners they make. So the limit would be if your body will autofocus with the f/stop and a quick look seems to show the AF will go to f/8.

https://www.sigma-global.com/en/support/accessories_compatibility/#tele_converter

CHG_CANON Loc: the Windy City

If I was the OP, I'd look at the note on the bottom of page 100 of the Canon EOS T7 Instruction Manual where they say extenders can be purchased separately, but autofocus beyond f/5.6 is available only in FlexiZone - Single and Live Mode. The technical specs on page 300 indicate all 9 AF points are sensitive only to f/5.6. I wouldn't throw money into an extender idea with this lens and this body until someone can demonstrate different from the Canon documentation.

nicksr1125 Loc: Mesa, AZ

Even if an extender would work, you lose 2 f/stops worth of light making the viewfinder image very dark. Your camera has an APS-C sized sensor. So, the 70-300mm lens will be the equivalent of about a 100-450mm lens on a full frame camera.

User ID

There are NO "quick questions" on UHH.
That would violate UHH Sacred Tradition.

47greyfox Loc: on the edge of the Colorado front range

I have two TCs. Both are 1.4. One is a Sigma recommended by Sigma for the 150-600 and 100-400. It’s IMHO horrible. The other is a Canon 1.4 that I only use with a Canon 100-400 ii. It’s actually very good and I can live with the 1 stop in light loss. I’ve never tried it with any other lens because their lengths overlap and consequently no need.

DWU2 Loc: Phoenix Arizona area

3kids3cats wrote:

I am looking at getting a Sigma 70-300mm F4-5.6 DG OS lens for my Canon T7. Does anyone know if there is a lens extender that will fit this lens. It is not a deal breaker, but just something I would like to get if possible. I have read online that a few years ago, no lens extenders would work on 70/300 lenses, but then I also read that with firmware updates and all, that they do now.
Can someone let me know what is what?
TIA

I have a Tamron 2X extender, and it works ok with my Canon, Tamron, and Sigma lenses. However, there is noticeable softness when used with zooms. Also, as others noted, autofocus can be a problem. So, I don't use it much. I still occasionally use it with my 90mm macro, since it makes it into a 180 macro, and lets me keep more distance from little critters. I'm using manual focus then anyway.