DD Mission Photos Slightly Out of Focus / Blurry


#1

I think I may have run into this issue a many months ago and thought it was a focus setting issue but I can’t remember for sure. Basically when using DroneDeploy I’m seeing slightly blurry photos. This isn’t the case when I shoot video and examine the frames in the 4K video (which is the same resolution as the photos.) This also doesn’t seem to be the case using DJI Go. The blurriness is only obvious if zoom in and compare to other photos so I could see A LOT of DD users possibly having this same issue and not even noticing.

Here’s a comparison. They are two different shots on different days of different buildings but, the one on the left was take at 190ft AGL or about 160ft above the roof. The one on the right was taken at 100ft AGL or about 70ft above the roof. The higher altitude shot looks much better. Examining the ISO I see the blurry one had an ISO of 100 with shutter speed of 1/120 where the clear one the ISO was the same and the shutter was much faster at 1/800 but this would be expected as that photo is from a brighter day. It appears (at quick glance) the other settings are basically the same.

Now I know DroneDeploy calculates a drone speed that makes it so photos are taken no faster than every 2.5 seconds in order to avoid any buffer issues. I’m wondering if that limitation may also have to do with avoiding motion blur?

But here’s the thing, should DD and the Auto settings of the camera work so that in most all but the most extreme conditions, the shutter speed should be fast enough to avoid blur when running a DroneDeploy mission? If not, then what is the solution as far as setting adjustments when running a DroneDeploy mission on a cloudy day in the morning to avoid the blur? Do you have to set a manual shutter speed or manual ISO setting? Is that even possible when running a DD mission? If not, then there is something definitely wrong with DD.

Here’s a folder with EXIF reports and the actual files.


#2

Cloudy days give me better results because the lighting is more uniform. To avoid blur I fly my missions at 9 mph (this is the speed limit I set in DD and it flies at that). If I let DD compute the max speed it selects around 16 mph. But missions flown at this speed had too much motion blur and I did not even try processing them. So slower may fix your problem. I fly at 325’ to clear 140’ tall trees and to be able to cover 20 acres with 80% overlap on one battery. I do not play with the exposure setting, I leave them on automatic under DD’s control.

Regards,
Terry.


#3

They day was pretty dark when it was taken and altitude was only 100ft AGL but to be honest I’ve never encountered what I would consider to actually be motion blur. But may it is. However if it was motion blur, wouldn’t the edges of objects that are parallel to the movement of the drone be crisp and the lines perpendicular to that have the most “blur” I’m not seeing that comparing shot to shot. All edges look equally blurring. I imagine it is quite common for people to confuse motion blur with focus issues, but at 100ft AGL isn’t the focus essentially set to infinite on the P4P?

I guess one way to find out is to reshoot the same roof on a much brighter day without changing anything and see how it turns out.

I was always disappointed that DD limited the speed so much. The P4P can take photos much faster than one every 2.5 seconds and when you are shooting 300 acres at 400ft altititude the difference between a photo every 2.5 seconds and 1.5 seconds can equal a couple of extra hours on site.

But as the EXIF points out, the blurry photo was 1/125 shutter and the good one was 1/800 (6 times faster) so it DOES seems to indicate a motion blur issue.


#4

Long ago I established a standard workflow procedure in which I turn off auto focus/exposure in DD and manually set exposure and shutter speed in DJI Go 4, the switch to DD and fly mission. I fly to mission altitude, point gimbal straight down over a good sample area (bare dirt if a construction site), and set exposure. F-stop is always wide open (2.8 if I remember correctly). I try to keep ISO at 100 and shutter speed at 1/1000 or faster. This means sunny days so I try to fly at around noon to minimize shadows and this is typically before cumulus clouds begin to get numerous on summer days here in SC. If a cloud looks like it will pass overhead during a session I will try to delay and let it pass if delay is not too long. I fly at 16 mph, usually around 250’ AGL. Also, I have to reset exposure and white balance after each battery change because the settings are lost when the drone powers down. I have gotten very consistent and razor sharp photos with this procedure. If cloudy day I will bump ISO before I slow shutter but not above 400 ISO. If I do use slower shutter I will set max speed even slower. I have found that speed, autofocus, and autoexposure kills, so to speak. :slight_smile:


#5

BTW, I am not sure that the shutter speed blur is necessarily from the ground speed. If you think about it, when taking typical still photos, the drone is motionless because you have stopped it to compose the photo. When mapping the drone is moving at a steady speed as the photo is snapped. The blur might not necessarily be cause by the relative ground motion but instead by vibration in the gimbal induced by the forward motion. When shooting video, this “motion blur” is often desirable because it is thought to give a smoother, more “cinematic” effect, hence many use filters to reduce light so that they can shoot video at 1/60 or 1/120.


#6

Interesting. Having to remember to do that procedure on each battery change is less than ideal. I’ve really seen this problem in a variety of lighting conditions and altitudes up until now. I’m wondering if maybe on cloudy days just setting the ISO to 200 or 400 (assuming it’s possible via DJI Go when using DD app to fly) and leave everything else auto could possibly be a bit simpler solution. The P4P X4S camera has a decent sensor with little noise up to 400 ISO in my opinion.


#7

I like simple solutions. Just flying slower gave me great results. Auto focus and auto exposure took care of the rest. I suggest trying this first. Use 9 mph and see what you get.

Regards,
Terry.


#8

When you are doing a jobs like a topographic mapping of 300 acres, taking thousands of photos, flying slower isn’t a good solution as it can add hours to how long the job takes meaning you have to unnecessarily charge the client more money.

On a 3D modeling job of a building, our photos taken with DJI GO where crisp, the DroneDeploy ones were not. Examining the EXIF on a couple the DD shutter speeds were in the 1/125-200 range typically, the DJI Go were at least 1/320. The faster shutter was because the sides of the building were white and the nadir photos from DD the roof is more grey with dark asphalt parking lot so a darker scene. We were flying 100ft AGL with 70/80 sidelap/overlap so the drone speed wasn’t that fast but of course the closer to the ground you are the faster it moves through the frame too, offsetting the slower drone speed.

In my estimation, basically, you need at least 1/320 shutter speed on most missions or you risk motion blur. I would think the developers of DroneDeploy should have found this out by now and modified their software accordingly so that it adjusts ISO but maybe that cannot be done literally “on the fly” because the software obviously doesn’t know how bright or dark the shots are going to be until it actually goes to take them.

So to me the bottom line is as far as camera settings, DroneDeploy isn’t as capable of managing the parameters to insure reliably good images as we had assumed.

The real stickler is I’m willing to bet a large sum of money that your average pilot using the software isn’t even aware of the small amount of motion blur and that their images should look better. It’s unoticeable when viewing the images on a typical HD monitor (1080P) which has the image zoomed out to fit on the monitor. I wouldn’t have noticed had it been a roof inspection where the client wanted to see very fine details of the condition of the roof and I’m very finicky about the quality of my work and had many many previous projects to compare the images to.


#9

So what will be your simplest solution? Change the ISO? Can this be done and still have DD control the exposure time and focus?

Regards,
Terry.


#10

That seems to be the golden question. I’m out of town and don’t have access to my drone so I can’t test. But it seems from what I read, you’re either all manual or all auto. On digital cameras they usually all have modes for full auto, or for ISO lock, or shutter speed lock where you can set the shutter speed and the camera adjusts the ISO on the fly. That is what would be the best solution. Otherwise, you’re stuck having to set the manual settings by putting the drone in the air and taking a few test shots to see what settings you need to change and you have to do this every time you change the battery! (yuk!)

But the other potential problem if it’s a full manual mode is that if there are large changes in lighting as the drone moves to different scenes, some shots may not look good. If you are flying manual you can change the settings yourself before you manually take each photo. But we are discussing setting in the context of running an autopilot mission with the DroneDeploy app. I fear that maybe DD nor DJI Go have the flexibility to impose a shutter speed lock and leave everything else as auto. But I don’t know for sure, yet.


#11

I haven’t tried auto modes in awhile so I can’t say if any of this has improved, but the main reason that I changed my workflow to all manual is that I found that both the auto exposure and autofocus were too slow to react as the drone moved along it’s flight path. For instance, when moving from forested areas to bare dirt (construction site) the first few images of the bare dirt would be overexposed as the camera was slow to compensate. I suspected that autofocus had some of the same problems even though, as mentioned in an earlier post, the focus should generally be set to infinity at the heights that we fly. I was concerned that the camera was refocusing on treetops then loosing focus when passing back to bare dirt. Almost all of my maps are of construction sites so I do not care about focus or exposure when passing over treetops. It is much more important that I get consistent results on the ground shots.

Regarding the effort for manual focus and exposure, it is not much effort and it has quickly passed into habit for me. I have the histogram turned on in Go 4. I also have focus assist turned on to get red pixels at edges of objects in focus (this is a big help for focus). At start of first flight I check all settings: white balance set to sunny or cloudy as applicable; camera settings to manual; ISO 100; Aperture to 2.8, etc. I take off and fly to altitude and over a representative area of bare ground using Go 4. DD is running in the background but I have not initiated the command to fly the mission yet. With gimbal straight down I set shutter speed using the histogram (mountain in the middle). Over bare earth the histogram is very uniform and there is really very little room for interpretation. I never shoot test shots anymore. I check focus and confirm autofocus is off. Then I open the DD app, run the mission check (I do not close Go 4) and send the drone on it’s way to first waypoint.

When changing batteries, upon power up I go back to Go 4. Invariably, the camera and white balance are set back to auto. I change camera back to manual and and WB back to sunny or cloudy as applicable. Focus and shutter speed are usually still good but I double check out of habit. I take off, fly back to altitude and do a final exposure and focus check (usually no change) then switch to DD and continue mission.

Is it a few extra steps? Of course, but as I said, it has quickly passed into habit and it only takes a few extra seconds. Most importantly, for the type mapping that I do it gives me dependable results virtually every time. If I were doing 3d modeling or other types of mapping where exposure changes were important, this wouldn’t work for me. I can tell you with certainty that this workflow drastically underexposes the forested areas typically located around the edge of my work sites but that is not important to me. So, clearly it is not a solution that would work for everyone. It is a solution that I have worked out from lessons learned over many missions and maybe that is the most important lesson of all: to experiment until you find what works for your typical flights and then apply it consistently. I definitely got more than a few bad maps on my way to where I am now and I still learn with every flight. I learned a lot from helpful people on this forum too and many thanks to them and DD for hosting it. And I still get a bad map occasionally but I think that comes with the territory. Plus, it is so darn cool creating maps this way that if I have an occasional “do over”, well that’s OK too. :slight_smile:

Happy flying,

Steve


#12

Exactly right Steve. Manual focus is the only way I can take a picture in DD without a guaranteed blurry result.

Your description of trees vs bare earth is equally well described. Only if I am at the maximum permitted altitude (wider FOV) or the sun is intermittent do I brave auto exposure. Every shot after a tree belt is over exposed otherwise.

A cloudy day and manual settings work best.

J.


#13

What is interesting is that I can’t remember having any of these issues using DJI Go, just using DroneDeploy. The video and photos taken with DJI Go are much more “reliable” than with DroneDeploy even shooting the same scenes with the drone moving at the same speed using either app.

I’m a Software Developer of 25 years and I’d be interested to know how DroneDeploy interacts with the camera settings versus DJI Go. Obviously either DJI Go is doing it better than DroneDeploy, or DroneDeploy has some bugs in their software regarding camera settings. I would think that auto exposure, auto focus (as mentioned probably irrelevant since it should be infinite in most cases), shutter speed and Auto ISO would all be controlled by the “engine” inside DJI go and DroneDeploy would just be a layer on top of that? But it appears not based on inconsistent results between the two.

It’s almost like basically it would be nice if DD had a “drone control only” mode where all it did would be drive the drone and control the timing of the photos to achieve appropriate sidelap/frontlap and it wouldn’t mess with any camera settings at all.

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#14

I have never had a problem relating to photos through Go4. I’m not a developer, but the non-qualified person in me does also wonder why DD doesn’t just fly the thing and activate the shutter button when required whatever settings are preset in Go4, whether it be manual or auto.

None of my blurred photos are due to motion blur. They’re all as a result of DD’s inability to focus the camera using its own interface.

DD currently has options within its interface to utilise Go4’s settings (and I use them) for the standard missions - I have to. This only works using ‘manual’ in Go4 as well though. What DD ought to allow is for the drone allow the automatic settings within Go4 to be adopted and we’d all have crisp shots I’m sure. Both for standard missions and progress reports.


#15

DroneDeploy with auto camera settings does great on my missions during both cloudy and sunny missions. I fly at a conservative speed and get good results. I understand that for those with large areas to cover, this is not an optimal solution and it would be great if there was a mode where you could set a higher ISO and fly faster with DroneDeploy still doing auto focus and auto exposure. But I do not see a problem with DroneDeploy if I fly within its constraints. I think the problem arises from pilots trying to fly at too aggressive of a speed for the conditions. My comments only apply to the P4P that I fly.

Regards,
Terry.


#16

Great advice here, StevenB. I’d just like to add that if your drone has a variable aperture, all the way open (2.8 in your case) may not be the best setting. Most variable aperture lenses are sharpest around the lower-middle of their range. In the case of my Mavic 2 Pro, a setting of 4.0 provides the sharpest image possible, but it’s “sharp” range is about 4-5.6.

If you get outside of that range it doesn’t matter what other settings you use, the images will be soft.


#17

Thanks Jason. By coincidence, I just read that on post from Mapping Group on Facebook. Good to know because on sunny days I am running shutter speeds up to 1/2000 so I would have a little speed to give up for higher f-stop. I have been shooting manual photography all the way back to B&W darkroom days so know about depth of field and all of that but didn’t think about the soft focus that would be caused by lens imperfections.


#18

I hear ya, I’m an old guy too! What can be difficult to remember for us SLR guys is that these drone cameras (in most cases) are just glorified cell phone camera sensors. Even the 1-inch sensors that are now showing up (in the case of my Mavic 2 Pro) are only the size of the early digital point-and-shoot cameras. I’d love to be able to strap a Hasselblad full-frame camera to a drone, but then it couldn’t take off!


#19

My wife used to shoot weddings and we had a Hasselblad 500CM. Those Zeiss lenses were amazing (with a matching price) and I loved that square format. Now that DJI has bought Hasselblad I expect more good stuff is to come. Mavic 2 was just the beginning. I expect some heavy enterprise level stuff in the near future.


#20

Thanks for all the great info here. I’ll be trying the manual settings in my next flight.

I had my first experience with “blurry” photos on a flight yesterday running in full auto. It was my first time flying so low, 100 ft agl, typically we’re up at 200-250 ft agl. I was assuming I’d get more detail and was sorely mistaken when I got back to the office.