I’m pretty sure I’m not the only one who had this problem. If you want to go from a crop body camera to a full-frame camera, you will be pretty afraid of the cost. I mean, let’s face it, the lenses are costly, and if you spend a lot of money on a camera you don’t have the money to buy a lot of new lenses. There is a sure-fire way to put crop lenses on full-frame bodies but everything I’m going to write here right now you do on your own risk. If you damage your camera, your warranty will be voided with this approach so keep that in mind. I’ve been using this method for a while now because I wasn’t able to afford all the new lenses, so let’s get to it.
This is our setup. We have a 5D Mark IV as a full-frame body, and we have a 24 to 105-millimeter EF lens and a 10 to 22-millimeter EF-S lens. I will show you now the differences between the EF lens and the EFS lens and how to put the EF lens on the full-frame body.
Let’s start with the EFS lens. If you take a look at the lens itself, there is a wide square on its white square. In Canon systems, there is the EFS lens, which is just made for the crop body. Typically, if you take the cap off, we have a plastic mount. Basically, this is the main reason why you cannot fit an EFS lens on a full-frame body, so let’s head over to the EF lens. If you examine the EF lens, there is a red button. The red dot shows you that it’s an EF lens. When you take off the cap on the EF lens, you’ll notice that the plastic cover is not as high as on the EFS lens. So here you can see the white square and red dot. That means the top of the EFS lens is the thing that is preventing you from using these lenses on the full-frame bodies.
Let’s take a look at how the EF lenses are connected to the full-frame body. So on top, there is the red dot that indicates that you need to align red dots to put the lens on the camera. On the crop camera so you have the red dot and white square so you can use both lenses, but you have a crop of 1.6 with the Canon cameras/ When you now try to put an EFS lens on the full-frame body this is what happens.
When you align it, the solution is to put new the lens on the camera. It’s pretty simple if you have a zoom lens. The most important thing is you don’t want to scratch the lens so you need to go to the narrowest angle you can. Use your finger to grab the cap and pull – this is what comes out. Now you take the body and the lens and align them. It should snap right in if you use the 10 to the 22-millimeter lens for the widest angle and you’ll notice that the lenses are a bit outside of the body. If you look at it side by side, the same thing does not apply to the EF lens so if you do this modification, you do it on your own risk.
What could happen is if the lens is too far out, and you take a picture, the mirror could hit the lens, and you could damage the mirror. Therefore, keep that in mind that you can totally use it with 12 millimeters, but I wouldn’t recommend going to 10. Now I’m going to explain to you how the crop lens is affecting the pictures on the full-frame body.
The lens isn’t big enough to support the big sensor of the full-frame body. There is a sweet spot where you won’t get the black ring, and you have a really, really wide angled lens and now let’s come to the catch if you use the 5D Mark IV. If you’re recording movies in 4k, the camera has a crop of 1.4 so if you use that lens and you go into a wider angle you won’t have the black ring around. Now, I’m at 12 millimeters, and as you can see, you have a beautiful wide picture with the little darker edges but not too much – it’s perfect for video making. I use this set up on my travel blog so basically most of the selfie videos I did I did with this lens and this camera. This is how I got basically a very good start with the full-frame body and a cheaper EFS lens. I hope this helps!