Canon Rebel T7 Auto Focus Trouble

[jhillne]

Just got new Rebel T7. The autofocus works with the included 18-55mm lens but when I add on any additional lenses (it came with several including a commander optics HD Telephoto) it absolutely will not focus at all. Is there something I need to be doing different when adding on an additional lens? 
Thank you!

[Tronhard]

Hi and welcome to the forum.

Are the other lenses Canon brand units?

[jhillne]

No. They are commander optics brand. However they were sold with it as part of an accessory pack. 

[Tronhard]

3rd party lenses, such as the ones you have are not supported by Canon: that is the responsibilty of the lens manufacturer.  I would recommend checking with the lens makers for support. It may well be that these lenses are manual focus units.

[Tronhard]

Just to be clear... when you talk about a "lens", are you talking about a whole camera lens (like your 18-55) or an add-one filter (that is one piece of glass) that screws on to the front of your lens?  I have managed to get to a computer and it looks like Commander make filters rather than lenses - the difference in terminology may appear subtle, but it is very significant.

If it is the latter, then you may be attaching a filter that is not the correct one for the kinds of photos you are trying to take.  For example a close-up or 'macro' filter will only work if you are extremely close to your subject and the result will be that the camera cannot get focus and won't take a picture - which seems a bit like your situation.

To be honest, these filter bundles are usually made from cheap glass and will degrade the images you take compared to just using the lens.  If you want to get a specific result, like taking close-up images of bugs for flowers, you can get pretty close with the 18-55, but if you want something a lot bigger, then you need a specific lens for that and not an add-on filter.

[ebiggs1]

"Just got new Rebel T7. The autofocus works with the included 18-55mm lens but when I add on any additional lenses ..."

It sounds like you purchased a big package deal from sources like Amazon and/or others. It had all sorts of 'stuff' included. The cold hard facts are, those packages are mostly junk. If it is a recent enough purchase return it today.

It is a, you get what you pay for, thing. Good gear costs. You are better served by going to an Authorized Canon USA retailer for your gear. Amazon itself is a Canon USA dealer but some of the marketplace stores are not.

[MikeSowsun]

Your T7 was not designed to work with these add on “accessory” lenses that screw onto the front of the lens.  If you try using LiveView, it may allow AutoFocus to operate .