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A couple of questions - PWM flicker, CrystalSky vs Smart Controller vs iPad


Well-Known Member
Jan 22, 2019

I'm considering to get a CrystalSky for use with my Mavic 2 Pro. I'm currently flying with an old Nexus 5X or an iPad 9.7" depending on what I feel like for the day.
Now winter is coming and smartphones and iPads struggle a bit with the cold, and in the summer the iPad tends to overheat.

1. My first concern is if the CrystalSky uses PWM for backlight control, thus having a flickering backlight? I get severe eye-strain and migraines from flickering backlights, even if the flicker is fast enough not to be visible. That's a showstopper for me. Does the CrystalSky use PWM? One way of testing is to point a video recording device (phone or camera) with manual shutter speed settings at the screen at different brightness levels (20, 50 and 100% for example) and adjust the shutter speed back and forth while looking for lines to appear in the camera view.

2. I have to also consider the Smart Controller as an option. I need something that holds up to temperatures below freezing, and the summer sun while being dependable for professional use. The biggest benefit of the CrystalSky over the Smart Controller is screen size. 7.85" vs 5.5". I really enjoy the size of the iPad over my 5.2" phone. Much easier to see details. How do they compare otherwise for professional use and getting the job done? Same question about the Smart Controller as above. Does it have PWM flicker?

3. iPad is still an option. I haven't used mine to fly in below freezing temperatures yet. Does it work well? I didn't like how hot it got in the summer, so if I'm using an iPad to fly I'll get last years base model specifically for the drone and not put excessive wear on my shiny expensive one. If it's not reliable in the winter it's however not a viable option.

Any other thoughts?
Grateful for any help
View attachment 84338
7" 2200nits Quickly deployed and easily stored.
About $350 shipped (SC obviously not included)
LifThor SC Pro / FeelWorld FW279 7" COMBO
Sounds intriguing! But it is really odd to have online shop that sells only this product. This shop may quickly dissappear at some time.
I already have another feelworld model that was stated to be high brightness - 1000 nits but in reality it was no more than 300. Are there any objective reviews of that monitor?
LifThor makes the bracket and accessories.
The FeelWorld monitor is sold by FeelWorld Ltd.
Thor's Drone World sells the whole package.

The first three reviews I get in a Google search.

Anecdotally, I can tell you the brightness of the monitor is much greater than the 630nits from my S9+ or the 1000nits from my SC. The only downside is battery life, but I mitigated that with two additional batteries.

I also use the FeelWorld as a monitor for my Canon M50.
That's actually not a bad idea!
A Smart Controller and a field monitor. I wouldn't buy a Feelworld, but rather a quality product like a SmallHD, but that is surely an option. They even have vector scopes and LUT previews. Another option is to use the Smart Controller in the conditions an iPad won't handle, and fly with an iPad and the regular controller when the conditions allow.

Now the question is if the Smart Controller is PWM free...
Now the question is if the Smart Controller is PWM free...
I have no idea.
I can tell you that while I do not experience migraines with or without the SC, my flights are usually 20 minutes in duration and usually have a break of 10-20 minutes in between.
So eye-strain has not been a personal issue.

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