HELLO FELLOW DRONERS

As a photographer who likes to get the absolute best performance out of my gear, I went on a mission to test where the sweet spot lies in the DJI Phantom 4 Pro in terms of image quality. Below are the results, feel free to share your thoughts and share these findings amongst other pilots.

So what aperture should I aim to use with the DJI Phantom 4 Pro? Whats the best combo of Aperture/ISO and shutter speed? Check out the test below!

OPTIMUM APERTURE

Before reading on there is a few terms you need to know to understand the purpose of this test, check you know them all.

Aperture is the physical diaphragm made of overlapping blades that light passes between when entering the lens, the wider open this is, the more light will pass through to the sensor. By making the aperture smaller we reduce light entering and thus have more control over exposure.

Aperture is measured in 'F-stops' and written as f/2.8, f/4.0, f/5.6 etc. The smaller the number the larger the aperture. F/2.8 is a standard wide limit and f/22 is a standard smallest limit. All lenses are different with aperture range, generally speaking the large more expensive lenses can go wider and let more light in.

However, aperture also changes other elements to consider and this is where the amateurs get separated from the intermediates and intermediates from the advanced.

Depth of field is changed dramatically by aperture. As the aperture gets wider the depth of field gets shallower. Depth of field is the amount of area in your image that is in focus. A small or shallow depth of field has a very limited plane of focus, everything around that focus point will be blurry and more so the further away from that focal point. A large depth of field (f/22) will have a great amount of the overall scene in focus.

Now, here is the advanced part which is the crux of this article. As the aperture is made smaller, less light gets in, and the depth of field increases, but - the sharpness of the image is reduced. It's to do with the optics as less image detail is entering the lens as well as more refracting light inside the lens barrel from more aperture blade area. Between a few stops its quiet negligible, but a big difference can be seen at the limit of the lenses smallest aperture. An f/22 image when looked at closely will be very soft and flat detail. This flaw is called lens diffraction. Another point to consider is lenses widest aperture can often be pushing the optical limits to be as wide as possible and have a lot of distortion or lens discrepancies such as chromatic aberration (the blue or red halo edges around some subjects) which boils down to being unsharp.

So, without further ado, lets get down to the test and see which aperture performs the best on the DJI Phantom 4 Pro. 

All images were shot at ISO 100 with varying shutter speed to balance out exposure, the gimbal was locked so movement was not an issue. These are all crops of the original.

LET THE TEST BEGIN

F/2.8

The most light is getting in which is great, but the image detail is looking very, very soft. I can only just see some texture of the material coming through. This is common with a lot of lenses at their widest aperture and it explains why the Phantom seems to avoid auto selecting F/2.8 even when its really dark, it usually stays at 3.5 or 3.2 in my experience. I would avoid f/2.8 becasue of the softness.

F/3.2

Instantly you can see a big difference in detail coming through at less than half a stops difference. This aperture is acceptable in terms of sharpness.

F/3.5

Wow, another big step in terms of sharpness in just half a stop. Come to think of my last comment about F/3.2 being acceptable, at such a small aperture difference it would be worth taking a hit in terms of exposure for this. 

F/4.0

A small increase in sharpness since f/3.5, its negligible but the fact is the image is still increasing in sharpness despite any internal light refraction.

F/5.6

Just when you thought it couldn't get any sharper. This is a considerable amount sharper than the previous f/4.0 too. I'm always blown away at the quality of this tiny lens that flies in the sky for 30 minutes at a time.

F/8.0

OK here is a turning point. Not only would this image be much darker with a smaller aperture, but image quality is starting to soften up due to lens refraction.

F/9.0

Again, another step down in detail. I would say this is equal to f/3.2 in terms of sharpness.

F/11

Last and final test, there is no point in continuing from here as you get the idea, this is so soft its on par with f/2.8. Avoid this aperture where possible, use filters if you want to darken a scene instead.

CONCLUSION

Well there it is, the evidence doesn't lie. Image quality degrades after F/5.6 on the Phantom 4 Pro camera - meaning you will get the sharpest image at F/5.6. So if you are in really bright scenes you are better off locking the aperture at F/5.6.

However, you need to take into account your ISO and shutter speed.

You should aim to never raise your ISO on the DJI Phantom 4 Pro, always keep it at 100. This is because even at 200 noise becomes very evident. All sensors are different but this is one weakness of the Phantoms. Stay at 100 and you will be safe. Its illegal to fly at night in most countries anyway. 

In terms of shutter speed, it depends on whether there is any motion in your scene, how fast that motion is, wind moving the drone, and how high you are (motion speed is reduced in relation to the distance from the sensor). Generally speaking if you are taking a photo at 120 meters of a beach for example, you want to use about 400th of a second minimum to eliminate any motion blur of the waves or camera movement. You could push it to 320 of a second if it is really still however.

That said, the ultimate settings for the Phantom Pro would be:

ISO100, F/5.6, 1/400

However, if you need more light or a faster shutter speed feel free to go down to F/3.5 but no less to capitalise on the strengths of the DJI Phantom 4 Pro.

Hope this experiment was useful and answered your questions!

Any thoughts on you own findings feel free to let me know. This was a test I conducted in controlled scene so the results should be true and accurate. You can follow me on Instagram @jamenpercy.