The lens on FPV camera can often get loosened due to vibration or crashes. In this tutorial I will show you how to focus FPV camera lens in a few simple steps.
Further Reading:
How to Adjust FPV Camera Focus
The lens has a threaded shaft itself, and there is a lock ring (aka lock nut) at the base of the lens to stop it from moving once secured.
Most FPV cameras have digital sharpening, and you should lower the sharpness setting slightly before focusing the lens. I’d say 15% to 25% would be enough. After it’s in focus you can turn it back up.
To adjust the camera focus, you just need to screw the lens in or out until you find the sweet spot.
The first thing you want to do is to unscrew and loosen the lens from the camera. You should hold your camera facing away from you in this tutorial.
By turning the lens clockwise, both the lens and lock nut should come loose at the same time. If not, try loosening just the lock nut first by turning it clockwise.
For standard size cameras, you can just use your fingers to turn the locknut. With the smaller lenses on the Micro cameras, you might find it easier with a pair of tweezers.
Focus FPV Camera Lens – Turning Direction for the lens and Locknut
Make Sure Lock-nut Isn’t Broken
Before proceeding to focus FPV camera lens, it’s wise to check if the lock nut is actually broken. It’s the one thing that holds the lens in place and keeps it in focus, if it’s broken your camera will soon become out of focus again as the lens loosens.
Steps to Focus FPV Camera
Table of Contents
Finding Good Reference Objects
You can focus your camera using any object as reference. Find something with fine detail like branches, fences, tiles etc, that allow you to more easily see the differences in the image.
I personally find it much easier and more accurate using a focus test pattern (camera focus chart). You can print it on a piece of A4 paper: https://goo.gl/ckdyvV
Don’t use this image, use the one I linked for better resolution
Object Distance
The object distance you focus on matters. If you focus your camera with objects too close, the camera might look blurry with object further out. And vice versa.
If you are focusing on the test pattern, put it about 3 meters away (10 feet).
If you are using the surrounding as reference, you want to stand further away, around 10 meters (30 feet). As long as you can see clearly at this distance, you should be fine when flying FPV.
Turn the Lens and Adjust Focus
Now connect your camera either directly to a monitor, or to a VTX and display the image through a pair of FPV goggles. It’s best to do this outdoor in good lighting.
Loosen the lens a couple of full turns, and turn the lock nut slightly away from the camera so you can screw in the lens deeper later on,
Now tighten the lens but very slowly.
You should notice that the image will get clearer and clearer, until a point where it will begin to become more and more out of focus again. You should go back and stop at that point where it’s in perfect focus.
With a focus test pattern, you want to stop at the point where the blurry center becomes as small as possible.
Here is a quick video showing the focusing process through DVR.
Secure Locknut
Now, hold the lens with one hand, and no matter what, don’t move it! It can be helpful to mark the camera case and lens where they meet, to help alignment during tightening.
Turn the lock ring with the other hand towards the camera until it touches the base.
Note that when doing this, the lock ring is usually not tight enough to hold the lens in position. So what you need to do, is to hold the lock ring in place with one hand, and unscrew the lens back up just a bit (40-50 degree, 1/8 of a turn). Now release the lock ring, and turn both the lens and lock ring inward, so the lock ring snugs up against the base, and the camera should also come back in focus.
This might not work the first time and you have to go back and adjust the position of the lock ring. Just keep repeating until you get it just right.
You definitely want to make sure the lock nut is fitting tightly against the base. Otherwise it can move with the lens during flight or in crashes.
Still Out of Focus?
If none of the above helped, and you are still getting a blurry image from your FPV camera, chances are you have a faulty camera. It could either be the lens, or the image sensor. Try a different lens see if it works.
Sometimes dust and water can get trapped inside the lens too which might require a good clean or replacement.
15 comments
There is another side to this exercise. The goggles and the camera are really the one unit. For this reason they need to work in unison. If possible they should have the same specifications. In analog video, like the old analog TVs the screen is populated top to bottom or vise versa. In a perfect situation the lines from the camera should be 1 for 1 with the goggles screen. If the screen has more lines than the camera you will experience some strange effects that look like those displayed in your examples.
A camera with a 4:3 sensor and 600TVL produces 450 vertical lines. 600 sounds better than 450 so that’s what they advertise but it’s not what’s important. These days most screens advertise the vertical but the camera manufacturers are still in 1970, so you have to do the conversion. If you have goggles ($$$) that have 720 or 1080 horizontal lines you should match them with the right analog camera. More camera lines is much nicer than less but 1:1 is ideal. You will be happy with the result.
Hi Oscar
Judging by the comments below you may have missed something. ie screwing the the lense inward moves the focus further away and outward brings the focus closer. As cameras have become smaller this process has become more difficult, as you said.
PS Love your howto web.
Hi Oscar,
thank you for that excellent howto. I focused my FPV cam perfectly.
However, my Caddx Orca 4k has been shipped with a misaligned focal length so I disassembled it and tried to refocus it by myself.
Given the fact, that this is an action cam I wonder what is the best way to find a focus here.
How far would you put the testpattern?
The live view is not helping at all when I try to focus it on far away trees, so I have to take out the SD and check the images after every adjustement. Is there a trick?
Thanks for this great guide. I have a new caddx turtle v2 and the right side is in perfect focus but left side blurred. Have tried to refocus but can’t get both sides in focus. Any ideas? Thanks
Heat may loosen any adhesive holding the lens or ring in place. You’ll want to be careful not to damage anything nearby.
Hi Oscar,
I got Video from my dji air unit very sharp in the center but blurry in all 4 corners, do you know why?
You probably have Focus mode enabled, which is normal.
Search for focus mode in this article it explains it: https://oscarliang.com/dji-digital-fpv-system/
“By turning the lens clockwise”
Anti-clockwise…
depends on which way you are looking at the lens, it’s clockwise if the lens is facing away from you as I mentioned.
Great vid and description, all makes very good sense, the only problem I keep having is that when you Tighten the Locking Ring at the point you have previously marked the ring itself pulls the lens IN a bit more than when focusing without it, that can put your focus out again even if you are exactly on the marked position. The ring pulling the lens in a fraction is like turning it in so to compensate you almost need to refocus again on your target as you lock the lens in place.
Thanks again, this is a good help.
My lens is glued in position and chipped away the glue as much as i could but still no luck getting the Mobula7 lens to focus in due to all the glue they put on it . Any suggestions on what i should try next?
Not much you can do really if the lens is glued in place, you can damage the camera further by forcing it.
I’d probably contact the seller for replacement.
Acetone might dissolve the glue, but Be careful about it getting on anything plastic.
Hello,
What is best way to focus RunCam Split 2 lens module?
In the field, I tend to adjust focus until things start ‘shimmering’, and straight lines start to show ‘pixelation’ or staircase effect – especially when you move the camera slightly. If you maximize these effects, you *should* have perfect focus when looking back at the HD footage later on.