questions about a zoom lense

[FineVisionz]

Hello,

 

I am looking in getting a Canon EF 70-300 telephoto lens for my cannon EOS T3 Rebel.  The only concern is that from a few videos I have seen,  it doesn't zoom in very far.  Here is the video I am talking about,

 

 

My other camera which is a Powershot SX40 HS which has a non changeable 4.3-150.5mm lens on it and it appears to zoom in a lot further than the Canon EF 70-300 Zoom lens. 

 

I would think that the 70-300 would have 2x the zoom capabilities.

 

Can anyone please clear things up with me?

[79wjd]

The actual amount of zoom on the lens is dependant on the size of the sensor. For example, a 70-300mm lens is 70-300 on a full frame (35mm) sensor. But is 105-450ish on a crop sensor(like you're camera).

So, the smaller the sensor the larger the focal length scalar is.

[FineVisionz]

The actual amount of zoom on the lens is dependant on the size of the sensor. For example, a 70-300mm lens is 70-300 on a full frame (35mm) sensor. But is 105-450ish on a crop sensor(like you're camera).

So, the smaller the sensor the larger the focal length scalar is.

I don't have a lot of knowledge about sensors and etc.  So could you just sum/make it camera noob friendly on what kind of zoom should I expect with a lens like the 70-300mm?  Haha

[79wjd]

I don't have a lot of knowledge about sensors and etc. So could you just sum/make it camera noob friendly on what kind of zoom should I expect with a lens like the 70-300mm? Haha

http://static.nikonusa.com/Lens-Simulator/simulator.htm

(It will be much less than your current camera, but you'll also be able to zoom in more after the fact). I believe the focal length of your sx40 is up to 800mm.

[FineVisionz]

http://static.nikonusa.com/Lens-Simulator/simulator.htm

(It will be much less than your current camera, but you'll also be able to zoom in more after the fact). I believe the focal length of your sx40 is up to 800mm.

So would the 70-300mm lense option with FX format + FX format body with the crop option checked resemble the canon t3 with the 70-300?

[79wjd]

So would the 70-300mm lense option with FX format + FX format body with the crop option checked resemble the canon t3 with the 70-300?

yes. It would actually zoom just a tiny bit further on a t3 due to a slightly smaller sensor (but it's a very slight difference).

[FineVisionz]

yes. It would actually zoom just a tiny bit further on a t3 due to a slightly smaller sensor (but it's a very slight difference).

Ok, thank you!