Improve recording of simultaneous bright outside and dark instrument panel

RobertK

Filing Flight Plan
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Apr 3, 2019
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RobertK
Hi all,

I just started taking flying lessons in NorCal. To improve my learning, I decided to record cockpit video and audio, which allows me to go back to any point of time in the lesson.

On my last flight I hooked up a GoPro Hero7 to the cabin ceiling and I'm pretty happy about the field of view and with 1080p recording I can read all the instruments, which is what I want.

(Un)fortunately the weather in California is mostly nice, which means the outside is very bright, while the dark instrument panel is most of the time in the shadow = very dark. The result is that only in turns like in the attached picture, where the sun is lighting up the panel, the video shows the outside. 98% of the remainder of the flight it shows nothing but white glare in the front window. Is there any trick to convince my GoPro to improve the High Dynamic Range of the recording to show all the dark panel details as well as the outside scenery? I assume a post recording processing will not help much and be of tedious work.

One thing I'm going to try is to use the more forward mounting spot in the red circle. Maybe it changes things as more of the video becomes brighter in general, but it's located just right in front of our heads, so I'm guessing it's gonna be a quite a distraction and that's a no-go...
cockpit recording.jpg
Thanks a lot for your inputs!
Robert
 
Filter with bottom part clear and top part darker. You can get them for regular camera for landscapes and such. I believe they are called graduated neutral density filters.
 
My camera has a setting to turn HDR on or off. It (an inexpensive GoPro imitator) cannot do HDR at the highest resolution and frame rate (ok for me, as I record at 1080p/30fps). Presumed you've looked at the GoPro settings to see if HDR is on (or if it is always on).

If you've already tried adjusting the EV value to get the best balance between inside and outside exposure and it hasn't worked well enough, and if you don't go for a gradient filter, then the only other thing I can suggest is 2 cameras. One directed towards only the panel and one pointed outside. You already have the 2 mounting locations, so 2 cameras should be easy to install. If you don't want to pay for another GoPro, you can find lots of imitators that work just fine for as little as $50 on Amazon. Every one I've seen will work with the GoPro mount shown in your photo.

Two cameras call for more post production, but not all that much. If you want to minimize the work, you can just have the software sync the videos, then set up a either a shared screen, or a picture in picture screen, and leave them that way. You might get more value swapping back and forth between PiP views to maximize the view that seems more important.
 
Incidentally our resident 182 guru is also almost a PHD on cameras ... @sinister
 
I think you will like having two cameras. One on the panel, one looking out. Very easy to make a video with both running times together. Will make for some excellent debriefing!
 
I used a GoPro suction cup mount on the drink left corner of the windscreen. This was able to catch my gauges and a good look outside. Where in NorCal are you training? I just got my ticket last year and it was awesome training up here during the springtime as it was very green everywhere!!


Sent from my iPad using Tapatalk Pro
 
Hi all,

I just started taking flying lessons in NorCal. To improve my learning, I decided to record cockpit video and audio, which allows me to go back to any point of time in the lesson.

On my last flight I hooked up a GoPro Hero7 to the cabin ceiling and I'm pretty happy about the field of view and with 1080p recording I can read all the instruments, which is what I want.

(Un)fortunately the weather in California is mostly nice, which means the outside is very bright, while the dark instrument panel is most of the time in the shadow = very dark. The result is that only in turns like in the attached picture, where the sun is lighting up the panel, the video shows the outside. 98% of the remainder of the flight it shows nothing but white glare in the front window. Is there any trick to convince my GoPro to improve the High Dynamic Range of the recording to show all the dark panel details as well as the outside scenery? I assume a post recording processing will not help much and be of tedious work.

One thing I'm going to try is to use the more forward mounting spot in the red circle. Maybe it changes things as more of the video becomes brighter in general, but it's located just right in front of our heads, so I'm guessing it's gonna be a quite a distraction and that's a no-go...
View attachment 73080
Thanks a lot for your inputs!
Robert

That's not 'The Finer Points' in the right seat is it?
 
A graduated density filter might help but two cameras is the best way to get it done.
 
Two cameras, as many have mentioned, until "single-shot dynamic range" becomes much greater.
 
Hi all, thanks a lot for all of your quick replies. I'm trying to avoid the 2 camera setup so far, as I have absolutely no clue about post processing so far and my spare time is limited. Right now I can just pull the video off my GoPro and can use it as-is for listening into the ATC chatter or look at the panel. But I knwo what you mean, once I have multiple cameras and be more profound in post-processing, I'll be able to create awesome videos.
I'll have a look into the GoPro menues once more to see how I can change EV values or search for a graduated filter.

Thanks again!
Robert
 
You don’t need 2 gopro $$$ cameras, get yourself a second cheaper (apeman for example), or use your cellphone. Videos that have different camera angles are more interesting if you are trying to appeal to a broader audience.


Tom
 
You don’t need 2 gopro $$$ cameras, get yourself a second cheaper (apeman for example), or use your cellphone. Videos that have different camera angles are more interesting if you are trying to appeal to a broader audience.
Tom

Thank you, that's understood. Right now I don't want to appeal to any audience but to myself in order to debrief or go through a certain exercise again. Having a clear view of the outside makes it easier to find the right spot in an hour long video you are searching for. But you guys are right, once I concentrate less on how to fly, I might fly to more interesting places and then having more cameras will better capture the beauty of flying :)

Here's a picture of a guy who flew the exact same plane and although not ideal, you can see the instruments as well as the outside.

N9968F cockpit.JPG
 
Having both of your sunvisors down caused the camera to crank up the exposure.


The windshield takes up a larger percentage of the image than in your video so the exposure is better balanced between inside and outside.

It's also usually easier to lighten dark areas in post-production than darken light areas.
 
Hi all, thanks a lot for all of your quick replies. I'm trying to avoid the 2 camera setup so far, as I have absolutely no clue about post processing so far and my spare time is limited. Right now I can just pull the video off my GoPro and can use it as-is for listening into the ATC chatter or look at the panel.
If that's all you want to do, there is no need for post processing. Put one camera on the windscreen facing forward, put the other low on the side window facing the panel. Then just look at each video separately and take your notes from each.
 
@dmspilot called it!

The scene your are presenting your Gorpo has so little bright area compared to the rest of the scene that it cranked up the exposure (lets in more light) to lighten up the majority of your scene which includes the panel, the visors and your heads :) In doing this the outside sky (very bright) is now blown out.

As @dmspilot also mentioned, given imagers and the raw data there is usually some extra data in the shadows (the dark panel) but the highlights (the sky) is blown out and there won't be any data to recover. If you plan on using a single camera and want to recover part of the image you are better off to underexpose a bit and then increase the "shadows" in post processing. I use Adobe Premiere and can recover some of the darker panel regions but you can only push it so far before it gets noisy and grainy.

I know people keep saying one day there will be enough Dynamic Range (the ability to capture from brightest to darkest) but there already is in modern DSLRs. But you still actually need to post process them and raise the shadows on a per scene basis. I am not aware any camera's that are doing this currently on the fly unless they do true HDR (which requires multiple images) which is not friendly with video because true HDR needs to images with no motion. Also, the video (especially from gopro) is very compressed so there's not much room in the data stream to hold all that valuable shadow detail. Actually the opposite the compressor knows we don't see well in the shadows and will chuck some of it. A still picture on the other hand has rich 14-bit data with all the shadows preserved.

@Juliet Hotel mentioned a "Graduated Neutral Density Filter". This is generally the right idea. The filter is darker on the top and transitions to transparent on the bottom. The camera is tricked into thinking the entire scene requires the same exposure (for the bottom panel area) and viola the sky has the nice blue color, clouds are not blown out, etc. However in your scene you have heads on both sides up high. So they would look darker near the top of your head and brighter down at the bottom. In the ideal world there would be a ND filter just where the windshield is! Or better yet, the windshield would be heavily tinted...both of which are not possible.

One thing I'm going to try is to use the more forward mounting spot in the red circle. Maybe it changes things as more of the video becomes brighter in general, but it's located just right in front of our heads, so I'm guessing it's gonna be a quite a distraction and that's a no-go...

If you are restricting yourself to a single camera, I would move it farther ahead to only see the panel and outside the windshield. Then tilt it down gradually so that the ratio of what's outside to whats inside favors the view you prefer. You may find that you still need the outside a bit washed out to have a brighter panel. Or you can then lift the "shadows" in post with an editor. Gopros are small and it shouldn't bother you but its up to your CFI. Also, can it still see the panel?

Take a look at @Radar Contact's videos on YouTube (310 pilot). If you notice his camera looking towards the panel, it doesn't include much of their head. Actually I don't think you can even see Jamie's head. I try this same shot and I don't get the same results. I believe its because his panel is dark. Ours is light tan. Since ours is light tan it drops the exposure. But because his panel is dark his scene must favor exposure for the panel slightly more than the outside but in a very nice combination. Or maybe he has a Graduated ND filter and hasn' told us yet :)

That is the other advantage of leaving the pilots out. You can then put a graduated ND filter on and align the dark part to the windshield and have less weird wonky dark areas.

Another solution to this problem is to add light. I believe if you could cast bright LED lights onto the panel it would work. But where the heck would you mount the lights. And that won't make any of the panel displays any brighter.

This one might make you laugh. If you are stuck with the scene you have. Wear something really bright on your heads. That will trick the gopro into thinking there is enough bright areas in the scene to drop the exposure.

The last option worth mentioning is in gopro they have the advanced mode. You can literally lock/limit the ISO and exposure and even the frame rate. You can always go here and tweak the exposure adjustment (often called EV) and crank it down a few steps. Or fix the shutter to you liking (it will be rather high to see the sky clearly). That is what Hollywood would do. But they would be creative with the shot and lighting and avoid what you see when you do something simple like a turn and it all changes. For the shot you want the big motion picture guys would use a graduated ND filter and some fill lights. Way, way, way to much to even consider in a normal cockpit, let alone student pilot flights.
 
This one might make you laugh. If you are stuck with the scene you have. Wear something really bright on your heads. That will trick the gopro into thinking there is enough bright areas in the scene to drop the exposure.
indeed it did :D

The last option worth mentioning is in gopro they have the advanced mode. You can literally lock/limit the ISO and exposure and even the frame rate.

That's exactly what I did on my last flight. I cranked down the EV level to the minimum, which looked good during sunshine. But when we where about to take off for the flight, the Bay was covered in cloud and rain :D Unfortunately I had to use another plane, which did not have any GoPro mounts, so I had to use the "windshield" to just look outside. Well, as dmspilot said, it's much easier to increase the brightness then to lower it. I downloaded VSDCfree for postprocessing and it worked quite well to brighten everything. I hope to get the previous plane for my next flight again to check the more forward facing camera mount and play around with the EV settings. Last step is to buy a gradual lens in case I cannot make it work.

Thanks a lot for your all comments! It really helps to discuss the options and look for the right things to try out!
 
Here's an example of using the Lumetri Color adjustment tool in Premier Pro.

The shadows (very dark areas) are increased and highlights (extreme bright areas) are decreased. I only adjusted on the right half so you can compare vs the original panel "darkness". What I like is in shots like these the sky doesn't get effected much. I stopped lifting the shadows when I started seeing noise. A DSLR like a Sony A7 series would probably allow 2x as much adjustment as this gopro video.

PP_ShadowsLifted.jpg
 
Here's an example of using the Lumetri Color adjustment tool in Premier Pro.

The shadows (very dark areas) are increased and highlights (extreme bright areas) are decreased. I only adjusted on the right half so you can compare vs the original panel "darkness". What I like is in shots like these the sky doesn't get effected much. I stopped lifting the shadows when I started seeing noise. A DSLR like a Sony A7 series would probably allow 2x as much adjustment as this gopro video.

View attachment 73273

Cool stuff. What about protune on the GP and needing EV changes? I mostly fly in Seattle, so I don't have shadows. Haha!
 
For a while I was using more of the ProTune settings:

NOTE: All of these are based on using a ND4 filter + Circular polarizer. The ND4 is a compromise for prop blur ("bananas"). You still see them in the brightest light but not so dark that it totally starves the gorpo of light. The circular polarizer really helps with reflections on the windshield, cloud/sky contrast and reflections on lakes. The circular polarizer adds to the total ND effect and probably gives me ND5. The downside to this is flying near sunset or very overcast, then the gopro starts wanting to use higher ISO. I hate all variable ND filters and they do not jive with Circular Polarizers.

ISO Limit: 1600
Even this is crappy but you definitely don't want it going to 3200. Without all the filters in front it will be less likely to go to ISO1600 so my case is a bit unique

EV: 0 or slightly negative
I usually leave this at 0. Its a no win battle. @RobertK used it the best way to run the scene a bit darker and boost the shadows, But we do a lot of turning in a airplane and what is good going one direction can be terrible going another direction. By setting it negative the prop bananas will be worse because it might speed up the shutter.

White Balance: Auto or 5500K
I used to force it to 5500K which I like because there is no automatic change while recording. But the auto seems to do a good job and then less need to re-balance in the editor.

Color: GoPro
I do like recording in FLAT but you have to mess with it more in the editor. Plus, I just don't think the gopro has enough dynamic range to warrant recording in FLAT and then brining it out. This is the one I will dabble with more as I have time but for now the Gopro colors are fine and less hassle.

Shutter: Auto
Now if a person could just fly one direction, no changing light, etc - this is THE setting. Ideally you would stack up the filters and set this to 60 or 120. You would get beautiful prop blur and little to no "Jello" effect due to vibration. But all it takes is one turn into different light or sun going behind a cloud and the panel get way to dark, etc.

Sharpness: HIGH
Once again, you can shoot it LOW and mess with it in the editor but the gorpo shoots pretty nice sharp video so why mess with this. I have tried it on LOW and I think you can ultimately get a sharper image but not by enough to really matter.

Now, If I was shooting for a VLOG or something I would probably try the following and edit in post:

Filters: ND4 + Circular Polarizer (Ideally ND6 + polarizer)
ISO Limit: 800
EV: -1 (Unless its really overcast, near dark or night flight)
White Balance: 5500K or 6500K (depends on the day - still not RAW as the video is too compressed)
Shutter: Auto (unless I could reset it for each scene which means someone else is flying)
Color: FLAT (adjust in post)
Sharpness: LOW (adjust in post)
 
Looks like I'm going doing something right! Trial and error got me to about the same as you're suggesting. The circular polarizer is going to be added. I think that will help the exterior 4's vids I have collecting bugs and oil.

Thank you for that post!
 
Can anyone recommend a good gradient ND filter for GoPro? The only one I came across was the "PolarPro" filter but the reviews of it was universally very negative. https://www.bhphotovideo.com/c/prod..._pro_h5b_1015_venture_filters_3_pack_for.html
Ya should be able to put on any filter you wish with this:

https://www.nflightcam.com/products/nflightcam-propeller-filter-for-gopro-hero5-black

The filter is a 58mm that has threads to attach it to the adapter.

Also, ya can buy a cage and put on your own filter. This one is 52 mm

Case frame skeleton thingy

Does that help?
 
Buy any gopro enclosure (example below) with 52mm or 58mm filter threads. And then buy a standard graduated ND filter:


Enclosure:
https://www.amazon.com/gp/product/B01M7XXKBE/ref=ppx_yo_dt_b_search_asin_image?ie=UTF8&psc=1
There are now many out there for about $19 and are the same thing. I like having all metal and it has a side screw to tighten the gopro inside the housing so it won't rattle inside (that can happen, bad). These are great with RAM ball mounts. A bit heavy for the stock plastic gopro mounts. Most importantly, has the 52mm front filter threads and you can put a cheapo lens cap on it to protect the gopro lens.

Cheapo Graduated ND Filter (its cheap but decent):
https://www.amazon.com/ZOMEi-GC-Gra...onics&sprefix=52mm+gra,electronics,150&sr=1-5
If this works you are good to go. If it works but optical quality sucks (very likely!), then get a Tiffen or Hoya or Promaster. If you don't get enough of a gradient look for a ND8 instead.

NOTE: When buying these its easy to get mixed up and purchase a "Variable" ND filter. That is a entirely different filter.

I was just thinking of something. If you like this "Graduated" or "Gradient" filter you could spin it around 180deg and night to bring in all the outside light and dim the panel!
 
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