Open Linux Forums
Like Ubuntu forums, except with beer.
Member
Joined: Oct 26 2017
Posts: 379

The good lady and I just got back from our annual visit to Hilton head Island, had a very good time there. I got to have a grilled oyster poor boy sandwich for lunch for six days made this old man very happy. I managed to get 2 good photos one of a Bufflehead Duck and the other of a group of White Ibis huddle together on grass in the sunshine trying to get warm.
Which brings me to this I am using a Cannon EOS T7i camera with an EFS 18-55 zoom lens. I found a 70-300mm lens that will work with this camera and has auto focusing which with my eyes I need, can any one tell me how much more magnification I will get with this lens.

dinga

Administrator
Joined: Nov 08 2017
Posts: 817

nubimax wrote:

a Canon EOS T7i camera with an EFS 18-55 zoom lens. I found a 70-300mm lens...can any one tell me how much more magnification I will get with this lens.

Hi Dinga.
Short answer: lots. 😀

The one you have is, with that camera, a bit longer than a "standard" lens. The sensor in the camera is a bit smaller than the picture area of 35 mm. film. Maybe you knew that already. Because the sensor is smaller, a given focal length is more "telephoto" than it would be on a 35 mm. camera.

This link you may have already read. It is, I believe, the camera you are referring to
Canon USA

Going on the information there, I had a look here
Wiki article regarding the sensor format

and here
Wiki article regarding equivalent focal lengths

On the strength of that, 300 mm on that camera should be roughly equivalent to a 480 mm. lens on a 35 mm. camera. I don't know if that means anything to you, but it is a reasonably serious telephoto focal length. I won't get you a picture of a sparrow in flight that fills the frame, but for a group of ibis a hundred yards away it should be fairly useful.

I love telephoto lenses. 😉
I've got a Pentax digital. I believe the sensor is a fraction larger than yours. I have a zoom that goes out to 300 mm., and find that it covers most normal situations quite well.

Member
Joined: Oct 26 2017
Posts: 379

Thank you audiomick, that is very helpful. when I got the photo of the Ibis I was with in 10 yards of them if had not been so cold I would not have got that close, they were huddled up against a bank in the morning sun trying to get warm. several of the duck photos were just to far for a good photo with the lens I have. and do need that auto focus to get good photos any more.
dinga