Nano+ White Balance Issue

[RobertB]

Hello all,
I am an experienced real estate photographer and very familiar with white balance. When using my traditional camera gear, I don't have much issue getting my white balance correct. I capture images using "raw" (DNG) exposures and edit in Lightroom. My method works fine for everything except when I shoot with my Nano+. I am having a really tough time getting WB the correct. With the Nano+, I am shooting 3 exposure brackets with auto-exposure. I process the bracketed exposures with Lightroom's HDR engine. But even if I process just one exposure, the results are equally undesired.

The three dng files from the Nano+ are available from the link below. My resulting edited image, and a ground based fully edited image are attached for comparison.

Autel Image Test - Google Drive

drive.google.com

Any suggestions are greatly appreciated!

 

[herein2021]

Is this your first drone? I don't think you have as much a WB problem as you do an image that is lower quality than you expected. If this is your first drone then that would explain why you think it should look better. The Nano+ has a camera sensor that is smaller than most cell phones, so what you are perceiving as a WB issue is actually a bit depth deficiency as well as possibly some RYYB sensor color deficiencies. I have shot plenty of real estate myself and I would never use the Nano for that type of work, not if you want your footage to appeal to higher end clients, its sensor is just too small. With such a small sensor, the image will degrade further if you try to use HDR brackets with it. I stick to a single well exposed raw image and post process it normally in LR. with the EVO II Pro.

Also, keep in mind that the Nano+ uses an RYYB sensor vs the typical RGB sensor which means it will have problems reproducing colors as accurately as an RGB sensor...another reason I personally would not use the Nano+ for commercial work. RYYB is great for lowlight work, but it has problems accurately reproducing colors like an RGB based sensor. Here is a pretty good article on the pros and cons of RYYB sensors.

Even with my EVO II and its 1" sensor, the quality difference is very noticeable if I compare it side-by-side with my handheld cameras. But when it is only an aerial project, the image looks fine to me. The smaller the sensor, the more I see this brown grainy film in the footage that can't be removed in most situations and in perfectly exposed situations with a lot of contrast can only be removed by using curves. I see that same brown grainy film in your sample HDR image.

As far as how to WB aerial footage, I always shoot in daylight WB during the day and if I need to be precise then I find something on the ground that is white and properly exposed or gray will do if there is nothing white then I use the eyedropper to set the WB. In your reference image, I would use the skylight in the roof of the central building to set the WB.

Just as an example, here are two images I shot with the EVO II Pro which uses a larger RGB based sensor; both compositions have about the same DR as your example images but the quality difference due to the larger sensor is pretty noticeable. The WB was set to daylight and I don't think I customized it in post.

 

[RobertB]

Thank you for the thorough reply! I've had a few drones in he past - DJI Mavic Air, Autel Evo (the original), and now the Nano+. I think you explaination is spot on and between my (less than ideal) HDR processing and the liitations od thr Nano+'s senor, I was just expexting too much.
I shot this one for my own listing as I am a real estate broker as well as a RE photographer. I do not shoot any video for my listings or photography clients and was hopeful the Nano+ would do the job. Were you avle to access the original DNG exposure? I would be really appreciative if you could process a single exposure (or thebrackets) and see what you can get from it. I may be too stuck in my ways and have a hard time being objective as I have seen thr same brown film artifacts for yars and have come to accept it. I need to refine my process as your images have beautiful color rendition and accuracy. I am curious to see what th Nano+ can produce under more refined processing. If you want to take on a little tutoring gig, I'd be happy to compensate you for a zoom session on editing exterior and aerial images. My process uses the Oloneo processing software. Clients seem to like to exagerated saturation but something more realistic would suit my taste better. You can reach out to me at robert @ agentimagery . com if that is easier.

Kindly,
robert

 

[herein2021]

Thank you for the thorough reply! I've had a few drones in he past - DJI Mavic Air, Autel Evo (the original), and now the Nano+. I think you explaination is spot on and between my (less than ideal) HDR processing and the liitations od thr Nano+'s senor, I was just expexting too much.
I shot this one for my own listing as I am a real estate broker as well as a RE photographer. I do not shoot any video for my listings or photography clients and was hopeful the Nano+ would do the job. Were you avle to access the original DNG exposure? I would be really appreciative if you could process a single exposure (or thebrackets) and see what you can get from it. I may be too stuck in my ways and have a hard time being objective as I have seen thr same brown film artifacts for yars and have come to accept it. I need to refine my process as your images have beautiful color rendition and accuracy. I am curious to see what th Nano+ can produce under more refined processing. If you want to take on a little tutoring gig, I'd be happy to compensate you for a zoom session on editing exterior and aerial images. My process uses the Oloneo processing software. Clients seem to like to exagerated saturation but something more realistic would suit my taste better. You can reach out to me at robert @ agentimagery . com if that is easier.

Kindly,
robert

So I test edited the middle exposure from your bracket and all I can tell you is that the Nano+'s sensor is just not good for accurate color reproduction. There is a strong color shifted vignette, the bit depth is low, the dynamic range is poor, and sharpness is lacking causing muddy details. Basically, the image exhibits all of the worst weaknesses of small sensors combined with the problems with an RYYB sensor. If LR had a lens profile for this camera it might be able to fix these problems automatically, but it does not. You could create a lens profile for it or a preset but you will always end up with sub-par footage when compared to the larger RGB sensors.

At the end of the day, this particular drone appears fine for hobbyists and will be particularly appealing to the hobbyists who love to overexpose their night shots until it looks like daylight, but it is not up to par for anything close to professional work. The color reproduction is not accurate enough, the dynamic range of the sensor is not high enough, and the resolving power leaves much to be desired.

Below is what I came up with after some fiddling.....I had to create a radial filter to try to fix the vignette color shift, I pushed down the highlights and brought up the shadows to maximize the DR that the sensor was able to produce, I brought up the exposure a little to help the low end, and I added clarity and sharpening to create the perception of better resolving power. The image is better but took too much time to fix....at the end of the day, if you start with a difficult image you will spend a lot of time in post trying to get it to look the way it should which is not cost effective.

You need to start with a better source image to get better results with less work and that would be with the EVO II Pro or one of the larger DJI models. You also should stay away from RYYB sensors because the marketing hype is around night capabilities, they don't mention the inaccurate color reproduction and nonlinear color casts which makes it hard to correct in post.

If you create a preset that gives you a good starting point, the Nano+ might be ok for residential RE work and MLS listings, but not commercial work or higher end ($1M+) listings. I also would not use it for video because these problems would be impossible to economically fix in video.

 

[RobertB]

So I test edited the middle exposure from your bracket and all I can tell you is that the Nano+'s sensor is just not good for accurate color reproduction..

Thank you for taking the time and playing with the image. Your input is 100% valued and I appreciate the directness. I am glad to hear the original image is the source of frustration. I was optimistic the Nano+ would suffice for what I do. While it "works", it has not brought me the image quality I was hoping to see. I like the compactness of the unit but not at the expense of poor results.

Thank you again for your time and efforts! I think an Evo II Pro is in my future. I owe you a beer or cup of coffee for your time!