QBK
lvl.1
United States
Offline
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Hello again everybody.
Original poster here, with an update after an RMA.
I sent my P3P back to DJI service in California (generally a good experience with the RMA process, no complaints there). Got it back a week ago, and finally got the chance to do some tests.
As usual, there was no communication or explanation of what was done. However, the camera unit had been replaced (new one has a serial number starting with P79DCJ). And, yes, I peeled off the plastic.
First I flew around my backyard and took some footage of trees and stuff. Then, to isolate particular issues, I took the really boring photos that I'm attaching here. Here's the bottom line.
1. The new camera (#3) is different from the old one (#2), but equally bad overall.
2. This time, there's still a big blurry spot in the center, but the left side is the sharp one. The right side is in between.
3. Temperatures warmed up enough that I was able to test at 45-50 degrees F (about 7-10 C). I think this camera still gets worse as it gets colder, but I didn't bother testing below freezing.
4. To highlight the problem, I'm attaching two test photos. I struggled to find a good testing methodology, but I think this is pretty good. On a nice bright sunny day, I took off and hovered about 19-20 feet in the air, with the camera pointing straight down at my parking lot. Then I moved it around to place the painted number "24" in different spots on the frame. This ensures a flat field of view, and it also ensures that all the comparison pictures are of the exact same thing -- just in different places in the frame. And at 20 feet in the air, this is well within the most conservative estimates of the camera's design depth of field.
The two JPEGs I've attached to this post are crops of the same object, but from different parts of the frame in two different images. To my eye, there's a massive difference in sharpness -- when "24" is in the center of the frame, it's blurry, but in the lower left it's sharp. And this is despite the noticeable chromatic aberration on the edges of the frame, plus the fact that corner resolution is generically worse than center resolution in properly adjusted lenses.
Here are links to the original JPEGs.
Image with "24" in the center
Image with "24" in the corner
Both were obtained from DNGs using Lightroom with no processing whatsoever except default Lightroom settings. I looked at the out-of-camera JPEGs, and they're more or less identical except for JPEG artifacts (which is why I used the DNG version). I also took 4K frame grabs, and they looked the same too.
If you view the full photos at 100%, you can see that the asphalt is sharp and in focus in some parts of the picture, and not in others. It's not an ideal target, but I didn't have a brick floor handy. The main evidence is the quality of the painted numbers.
Conclusion: I'm frustrated, and not sure what to do next. I could: (1) give up, or (2) send it back again, or (3) take the camera apart and try to fix it.
Am I being too picky about image quality? Honestly, this isn't just pixel peeping. This amount of blurring really does stand out to me when I view 4K video on my laptop (which is 2.88K, not even 4K), or on my 4K TV. It makes the difference between "Ooh, that's an awesome scenery video" and "Ugh, that's disappointing." But maybe I should just drink more and learn to love 1080p.
If I send it back again, what are my odds of actually getting a "good" camera? I know they exist -- Camera #1 (that came installed on my P3P) was sharp across the frame. But maybe DJI's quality control standards have changed -- is this the new normal? (Or did I get fantastically lucky the first time?) Does every camera that comes off the assembly line now look like this? Will I just keep sending them back and getting equally bad ones?
I don't think I want to take it apart, except as a last resort. It would void the warranty with prejudice, and I suspect I'd just make it worse than it is now.
Anybody have thoughts, suggestions, advice, etc? Especially DJI people, if you're willing to comment -- is this a "normal" result, or can I expect better?
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Crop from the center of the frame
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Crop from lower left corner
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