Full Frame VS APS-C Crop Cameras (Sony A7II vs A6400)

Jameses Tech
May 18, 2020 · 6 min read

In this era of social media, content creation is key. Cameras are essential in creating content online, and they come in a wide range, from a basic smartphone to a professional DSLR or even mirrorless camera. Ideally, if you want higher quality content, you would go for a camera which gives the optimum image quality.

Photo by KAL VISUALS on Unsplash

What is the difference?

Today, we are going to be discussing a topic that has been brought up many times: whether you should be going for a full-frame camera, or an APS-C crop camera. In this article, I will be illustrating this with two Sony Alpha cameras, the full-frame A7II and the APS-C crop A6400.

Sony A6400 (left) vs Sony A7II (right)

Price Ranges

These two cameras both fall under the budget of $1000. Currently, in the market, these two are quite closely priced, with the A6400 at USD$998 and the A7II at USD$918. They both come with kit lenses, and both the kit lenses share a similar focal range, so it’s quite a close competition between the two.

Look at the differences in the size of sensors (the rectangle) of A7II (top) vs A6400 (bottom)

Crop Factor

Let’s talk about the first thing — the crop factor. What is a crop factor? There is a sensor inside every camera. The sensor in the A7II is rather big, while the sensor in the A6400 is much smaller. That’s what the crop factor measures. The sensor on the A7II is about 1.5 larger than the A6400, meaning that if there is a 50mm lens on the A7II, there will be a focal range of about 75mm on the A6400. And if there is an aperture of 1.4 on the A7II, there will be an aperture of about 2.2 on the A6400.

Photo by Technobezz

You can use a normal calculator to calculate this manually, or use an mm calculator which not only helps you calculate the focal range but also the aperture of the lenses. If you have other types of crop lenses, you can just use the calculator to multiply and see what kind of focal range you get. (https://mmcalc.com/)

Photo by camerdecision.com

Photography vs Video

People usually ask me which camera I recommend. For photography, I recommend the A7II, and for videography, I recommend the A6400. Now, even though there is a production difference of about 5 years, which has led to improvements in the A6400, I’ll still recommend the A7II. It has a full-frame sensor which captures a lot of information. Where the A6400 shines is that it has very good autofocus and has a total of 425 phase and contrast-detection points, whereas the A7II only has about 117 phase detection points. In case you are wondering what these are, these are basically all the points that are featured in the sensor that is able to capture motion more accurately. The more points, the better.

Contrast detection points
Difference in color, contrast, details as well as shadows and highlights

Color Rendition

But because of the improvement in technology, I would also recommend the A6400 because it has something called the S-LOG (the S stands for Sony). This S-LOG mode of recording is basically a very raw recording format which allows you to see sharper differences in colours once it is recorded and colour graded. When compared to a typical video recorded with normal settings, there is actually a vast difference between the quality of colours between the S-LOG and a normal MP4 video.

Flippable Screens

Now let’s move on to the screens. The A7II has a tiltable screen, whereas the A6400 has a flippable screen, which means that you can see yourself while filming. One of the reasons why I like using the A6400 to shoot is because I can see myself on the screen.

A6400 has a flippable screen

Stabilized Footage

Another area of consideration is the IBIS. IBIS stands for In-Body Image Stabilization. If you are shaking while recording, this function compensates to make the footage less shaky. Although the A6400 is a video beast, it does not have IBIS (an upper-tier camera in the same line, the A6600 does, though it is $400–600 more expensive). With that said, IBIS helps a lot if you are actively moving or doing a lot of vlogging as it compensates for a lot of the shakiness, whereas, in the A6400, the shakiness is actually very obvious. Some of you may be thinking — what about lenses which are image stabilized? There is actually a slight difference between the lens stabilization and body stabilization, where the lens stabilization fares poorer than the in-body stabilization.

How IBIS works (photo by thenewcamera.com/)

Lens Options

As for the range of lenses, the A7II is a full-frame body so you’ll need to use FE lenses which are the Full Frame lenses in the Sony Alpha system. It’s not to say that you can’t use crop frame lenses at all, but there will be a very strong vignetting and you will have to crop it further in post-production. On the other hand, the A6400 would be used with an E mount, which is the crop sensor mount, as well as the FE mount, so it can be adapted to a wider range of lenses as compared to the A7II. But for the A6400, you would have to do a multiplication of the focal range and aperture for the FE lenses.


Let’s talk about size. What is the main difference in size? There are 2 considerations here, the size of the viewfinder and the size of the body itself. The viewfinder on the A7II juts out, which may make it more challenging to fit into some of the smaller bags when bringing it out. For the A6400, the viewfinder is attached at the back, so it doesn’t jut out. But with that said, having a viewfinder that juts out definitely has an edge when shooting portraits.

A7II’s viewfinder juts out


Overall, the A6400 has a lighter weight than the A7II due to the smaller sensor and its internal technology. So if weight is a concern, the A6400 might be more to your liking. For Sony cameras, if you want something which has a longer battery life so that you don’t have to frequently switch out the batteries so many times, I’ll suggest getting the Z batteries. Unfortunately, both these cameras do not have them, though the upper-tier cameras in the same line, namely the A6600 and A7III, do. Z batteries have about three times the amount of charge that a normal battery has, so it is definitely much better if you want to save on the trouble of switching the batteries and carrying spares around. (Personally, I only shoot short content or photos, so the smaller batteries are still okay for me.)

Both these cameras are very valuable for money within the $1000 price range. In summary, I recommend the A7II for photography and the A6400 for videography. The A6400 has an edge as it can record in 4K which is not available on the A7II. All newer Sony Full Frame lenses are able to adapt to both these bodies, so they are both definitely good investments for the future. (PS: For a live review of these two cameras, do check out my Youtube video at the link down below!)


Jameses Tech Reviews

Jameses Tech Reviews

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