05-20-2025 11:07 PM
So I have a Canon EOS Rebel T7 currently with the 55-250mm lens and I was thinking about buying the 100-400mm Sigma lens and I was wondering if the 100-400mm would be compatible to the T7 so I wouldn’t need an adapter.
05-21-2025 08:52 AM
Make sure the lens will fit the EF mount. Specs should tell this. I have a Sigma 150-600mm that fits my T7.
05-21-2025 11:18 AM
If you are looking at the current Sigma 100-400mm f/5-6.3 DG DN OS Contemporary Lens then, no, it will not fit with or without an adapter. The only 100-400mm zoom I am aware of for your Rebel is the Canon EF 100-400mm f/4.5-5.6L is II USM Lens which, IMHO, is far better then the Sigma but more expensive. There may be others I am not aware of, however.
05-21-2025 06:42 PM
Thanks for the clarification. I always look to see if the lens had EF or RF preceding the specs. Does the DG DN OS have anything to do with your answer?
05-22-2025 10:44 AM
" Does the DG DN OS have anything to do with your answer?"
Not really. A Sigma lens name with "DC" means that the lens is designed for use with an APS-C sensor. These lenses are not typically designed for FF cameras. A "DG" name indicates a lens designed for FF cameras but they can also be used on cameras with APS-C sensors.
I am assuming the lens in question is the current Sigma 100-400mm f/5-6.3 DG DN OS Contemporary Lens. It does not come, yet, in a RF or EF mount. Again I was assuming the OP menat the new lens.
There was and older version the Sigma 100-400mm f/5-6.3 DG OS HSM Contemporary Lens that did. But it has been discontinued long ago but if that is what the OP is inquiring about than, yes, if he finds an EF mount version it will work. Sigma doesn't include the mount name in the lens name so there won't be a EF in the name. You have to know what you are buying.
05-22-2025 04:35 PM
DN means designed for Mirrorless cameras only. Early Mirrorless camera lenses from 3rd Parties. Were lenses with built in mount adapters basically. This was the case for most early 3rd Party Sony E Mount lenses. The lenses were basically designed for the old Minolta A Mount that Sony had purchased in 2006. A permanently attached adapter was added so the lens could focus to infinity. Basically the E Mount is smaller than the Minolta A Mount. So all E Mount to A Mount adapters had to step in size to the Minolta A Mount. Also the mechanical interface that the Minolta A Mount used was removed. Incorporating the Sony E Mount’s all electronic communication. The Minolta A Mount used a mechanical lever to control the lens aperture. With the lens mounted the aperture was wide open. With the lens unmounted it was fully stopped down. Now AF was handled 2 different ways with the Minolta A Mount. The original design used a motor in the camera body to control AF. Later they went with the same system Canon uses. Which is the AF motor built into the lens for AF. Sigma also had its own Mount the SA Mount. When it started making AF SLRs. The SA Mount is electrically similar to the EF Mount. But mechanically similar to the Pentax K/ PK Mount. Sigma now makes Mirrorless cameras with Leica/ Panasonic L Mount.
05-23-2025 08:41 AM
Thanks for the clarification.
05-23-2025 10:34 AM
"DN means designed for Mirrorless cameras only."
Great point, thnax, I should have mentioned it. But the rest .........................
Perhaps curious trivia but it has what to do with the OP's question?
05-23-2025 11:08 AM
I wasn’t sure if they were talking about the new Mirrorless version of the lens. Or an older version that you mentioned since the full name wasn’t mentioned. The other part of the message was for @Tintype_18/ John. Why Sigma and other lens manufacturers. Started designing lenses specifically for Mirrorless cameras. Most early Mirrorless lenses were based off older lens designs. Such as Sigma using the old Minolta A Mount instead of designing. New lenses specifically for the new Mirrorless Sony E Mount.
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