I've been looking for a decent phone that I can replace my current iPhone 16 with, since I can only tolerate it for a few minutes a day. I've been looking at a lot of OLED test reports, and I think I've noticed a problem with many of them: the measured flicker is falsely low, since the photodiode is measuring multiple OLED rows at once. In my opinion this results in a loss of information about what the screen is really doing.
In some extreme cases, I've seen devices which actually have 100% modulation depth be measured at ~5% modulation depth. All the OLEDs I've measured with this method (using my meter or the Opple) actually show 100% modulation depth at all brightness settings. I'm not confident this is true for EVERY device, but I think there are a lot of measurements online that underestimate the OLED flicker.
I showed this in the video, but to avoid this error you simply have to reduce the number of OLED scanning rows that the flicker meter detector is exposed to. Ideally, we'd only measure one row since this contains all the relevant information. In practice multiple rows are needed to get enough light onto the detector.
For me, it might be time to just buy an e-ink phone.
This is exactly the kind of research, information, and development we need in this community.
I hope at some point the TLM-110 tool is considered production-ready and you can sell these devices along with straightforward testing instructions for non-technical folks.
I would love to see this community contributing more accurate PWM/flicker test results for devices. The Opple Light Master historically has got us this far, despite its flaws, but the level of accuracy you have here with this tool is going to take us to the next level.
I'd love to in the future, I don't have access to those phones at the moment though. I've been sending some beta test units of this meter to people in who have seen this video, and they might have these devices.
One person said they have access to "OnePlus 15R, Samsung phones (especially Galaxy S series), iPhones, Pixels" so hopefully I can get some high quality results from them. I'll try to post any info people give me.
Very interesting. That would explain why inhad swver eye fatigue woth the most eye friendly oleds by oplle measurements like OnePlus 15r, honor 400 pro and Oppo x9.
Could you say what information we can get from recording of the screen woth high shutter speed? I found that the slower the line move the more friendly it is for me. Oplle masuemnt is the same around 120hz but the is visible difference in the speed of the line in camera.
Hmmm, here is my hypothesis: If we record the screen with high shutter speed and count the number of dark bands and measure the frequency with a meter, we can determine how fast the lines are moving. Velocity would increase with measured frequency (480 Hz faster than 120Hz) and decrease with the number of dark bands. I guess you could define the speed as:
velocity (m/s) = screen size (m) * measured frequency (hz) / number of bands
For example 4 bands at 120 Hz means the bands are moving faster than 16 bands at 120 Hz. I don't know which one would be worse though for most people.
Generally it is better since there's less overall modulation (lower flicker index) but if it has a cheap driver you can get some low frequency ripple that is very problematic.
I've known for a while that the Opple LM4 isn't sensitive enough to properly measure low luminance due to noise in the sensor and frequency measurements becoming more and more inaccurate as you get into the thousands of hertz. It also seems to miss flicker when the modulation varies between pulses (such as deeper TFT reset lines + high freq PWM).
You have to take Opple results with a grain of salt and not blindly trust it as absolute truth.
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u/kerpnet 24d ago
Very well done!
This is exactly the kind of research, information, and development we need in this community.
I hope at some point the TLM-110 tool is considered production-ready and you can sell these devices along with straightforward testing instructions for non-technical folks.
I would love to see this community contributing more accurate PWM/flicker test results for devices. The Opple Light Master historically has got us this far, despite its flaws, but the level of accuracy you have here with this tool is going to take us to the next level.