Lens/Camera Vignette/color shift!

[Sportflyer]

Ok I have a couple questions I have been researching this whole vignette/color shift issue as I am trying to color grade some dusk shots which looks like it amplifies this issue? So once I start pushing the colors around this vignette really shows its self a lot!! to the point of I am thinking of just trashing some clips. it basically makes it look like a cloudy mess around the outsides with increase noise! Even if you clean up the noise you still have that pronounced vignette of gradient color/exposure/light!!

1. Is everyone else experiencing this!??
2. What are you guys doing about it!!? or are you just letting it go?

So again are y'all experiencing this also? center of picture has decrease noise and as you start to move from the center to the outsides it becomes more noisy with the wonderful vignette... (circular gradient) and it looks like depending on how the sun hits the Len it become less of a pronounced circle and more of just certain edges with the cloudy mess!!! ugh this just might make me step up to the inspire, but love the portability!

Please tell me I'm not the only one seeing this!

Again any work arounds for this/post editing tricks?

 

[Sportflyer]

No one?!

 

[joshnl]

Can you upload an example of your footage that shows this?

 

[Sportflyer]

Ok this shows what I am talking about. Now if you look you can see it is in a circular pattern most notably at the bottom Left. Now I have other clips when looking straight down that fill up the the whole screen growing towards the outer edges like a perfect gradient of color shades (vignette) and some with just more or less in one corner/side and ones like this picture were you have a little bit on both side/corners... and as you can see there is an increase of cloudy noise which sure I can take care of the noise but then it just leaves me with a cloudy red/magenta fog and choppy color shades/jumps, still looking like noise to some extent!

Now is this just normal, just lens flare that hits the lens at different angles creating this vignette of color and noise?
Now obviously I dont get this all of the time, but it seems that with sun sets it is a pretty big deal as you can see, making for an unpleasant video! Im sure others have experienced this too? Do I just need to frame the shot better, and ether take it or leave it? Is it again just the nature of the beast of a compact camera.
Thanks!

 

[4wd]

It's rather badly affected by lens flare when sun is almost in frame.
You don't have the clear cover on surely?

 

[Sportflyer]

Correct!!! no clear cover!
Thank you figured this was what it was, as I shoot more sunsets and push colors more in post I guess I am just seeing the effects of this lens flare more!

Thanks again!

 

[joshnl]

Lens flare usually results in reduced contrast in certain parts of the frame, but I haven't experienced this extreme magenta tint myself. I did experience some magenta tinting the other day for the first time (both in video and in RAW stills), but it wasn't quite like what you're seeing - it was more restricted to very specific objects within the frame, like trees that didn't have leaves on them. These trees did have a very slight magenta tint in reality, but it seemed exaggerated in the video. I suppose it might be related. I wonder if DJI have gone and messed up the latest firmware. I'm on .900 - how about yourself?

In your screenshot, it looks like almost everywhere in the frame where there are shadows, they have this strong magenta shift. Are you maybe shooting at high ISO? And what settings are you recording in (e.g. D-log, etc.; saturation setting, etc.)? I'm shooting in D-log, saturation at -1.

 

[Sportflyer]

Yep the magenta color probably looks more extreme because the reds are pushed up in post. But you are right they are still there even without any color grading they just get worse with color grading.
My ISO was 100 and I think I was in D-Log, everything -1, except sharpening to +1.
Also using ND filter....
Which I am looking into further which also might be adding to the problem.... I have been noticing I may be losing a lot of detail in the shadows with under exposing? Why is there no Shadow warning like the zebra strips with like the highlight warning?
I think this would be useful for ND filters as I am finding it a bit tricky playing the game of keeping as much detail as possible in both the highs and lows... I think maybe it is under exposing the frame too much bring out this shift/vignette more as I have been trying to keep from blowing out the sky but I guess in return the ground then becomes underexposed?
And then you have the other choice of good exposure of the ground with a blown out sky!
What is the best way to go about this? finding middle ground with allowing some of the sky to be blown out, with making sure you keep as much detail in the ground shadows as possible?
And again why no under exposure warning?!

 

[joshnl]

I think there must be some seriously underexposed portions of the frame, since I don't normally see crazy noise like that (even putting aside the magenta tint) at ISO 100, except in very low light (e.g. around sunset). I don't think it's being caused by vignetting, since you can see it even in the middle of the frame (in the water). And I don't think it's due to ND filters, since, at least in the water, it looks more like compression artefacting than anything else, based on the very abrupt line between blue and purple (looks kind of like JPG banding).

I must say, I'm quite at a loss, and although I have a tough time getting good footage out of my Mavic in non-ideal lighting conditions, I don't have THIS tough of a time. Has this happened to you in other lighting / subject situations?

Getting ideal exposure is definitely a tricky thing with the Mavic. The dynamic range is quite poor, so you're right, it's always a battle between overexposed highlights and very noisy (or mushy) shadows. I'm realizing there isn't really a magic formula that works for all situations. In some cases, if the contrast between the sky and foreground, for example, are huge, you may have to live with a blown out sky to get decent looking footage overall.

I've had quite a bit of success with Neat Video, which helps remove noise from the footage - especially when paired with the noise profiles offered by The Film Poets. You do sacrifice detail in the process, but at least you can get decent looking footage in the end, even in tough situations. This seems to work quite well in sunrise / sunset scenes where you need to avoid overexposing the sky, but as a result underexpose the foreground. These situations can sometimes be even easier to deal with than a typical daylight scenario where you have a really bright sky and a moderately lit foreground, since with the sunrise / sunset scenario, the contrast between bright and dark isn't quite as drastic. But still, it's always tough finding the right balance between too much noise and an image that looks overprocessed due to noise reduction.

In any case, I've been a very serious amateur photographer for over 10 years now (and quite a good one, if I do say so ), with lots of experience shooting tricky scenes with nice cameras. Despite this, I have an extremely hard time getting good footage out of the Mavic, and struggle a lot with it in post (and spend a lot of time rendering and re-rendering, since noise removal on 4k footage is SLOW!). It is possible to get good footage, but that bloody camera is just so finicky that it makes it hard to do so consistently. I still love the Mavic overall, but this definitely does detract from the enjoyment.

 

[Sportflyer]

Ya I think it has to do with multiple factors such as with exposure, pushing colors, ND filter, your environment/indirect/direct sunlight/lens flare, using this type of compact camera etc... and when you keep adding those on top of each other It creates that perfect storm of a mess! As I review more and more videos it looks like it is most likely to do with that sunset at a certain time along with possibly using too strong of a ND filter starving the sensor for light and then that sun glare hitting it all at the same time...?

I also use neat video, helps a lot! I came across those film poets noise profiles as well, and I thought to myself they just trying to make a quick buck (not that they are all that much), there is no reason you could not make them yourself!? Do you really find them better?

And Its good to hear I'm not the only one spending count less hours rendering over and over again to work on achieving that perfect looking video (well as close as you can with the mavic)! IT is fun! but ya would be a whole lot easier if we started out with cleaner video!

Sounds like you and I need to look into upgrading to that inspire! The portability is still too nice to give up with the mavic!

 

[joshnl]

The thing with ND filters is, as long as your exposure is good, the camera won't know the difference. So with your ND filter on, as long as your histogram looks good, it won't matter that you're using the filter.

Before I pulled the trigger on those Film Poets NR profiles, I was definitely ready to be disappointed. But I have to say, it's really worth the money. Before getting those, I was constantly struggling with generating perfect custom noise profiles for every clip... it was really driving me crazy. But then, the first time I applied one of the Film Poets profiles, bam... it was like magic! You'll often have to tweak the sliders a bit, but it's just so much easier than starting from scratch for every clip. And the results I'm getting with them are better than any results I was getting before.

Another plugin that works really well, for removing that annoying flicker sometimes observed with the Mavic footage, is called Flicker Free. You should check it out if that problem plagues you.

An Inspire would be sweet, but like you said, you just can't beat the portability of the Mavic. I live in British Columbia and go hiking in the mountains all the time. My Mavic comes on pretty much every single hike with me, just in case (although I usually find some excuse to use it regardless of how uninteresting the scenery may be). Absolutely no way I could do that with an Inspire, or even a Phantom. Yeah, the video quality of the Mavic is quite limited; but I simply wouldn't be getting any footage at all if it weren't for that badass little drone.

 

[Sportflyer]

Right! But what I think I'm doing is not expousing correctly which does again give an underexposed noise mess... I want to say I saw my exposure run into the -2 or further! I keep my shutter to that 180 degrees and keep the ISO to 100... so often times the frames get underexposed!
Now since the only real option here is to bump up your ISO is that what you do? Maybe I should try and see if that helps, but then again higher ISO creates more noise!?
But maybe there is a trade off where ou are still better off bumping up ISO to hopefully recover some shadows so it is not a blurry mess and taking out the extra noise?

Also do you find that flicker free helps a lot on top of neat video? I thought neat video for the most part takes care of the flicker? What does flicker free do more? The other issues with flicker can come from not using ND filters which I believe you are using also and the there would be from to fast movement with lower frame rates which I don't think flicker free would help with?
Do you use flicker free on all your videos? Does it seem to help a lot like neat video does?
And I thought neat video with auto profiles/manual work like magic! So I can't believe the purchased ones are that much better? But it sounds like you thought it was another big jump with using the film poets profiles/presets making it that much better huh!?

Thanks again for all your input I also wondered about all these other plugins/profiles etc...

 

[joshnl]

I would say don't be too limited by the 180 degree rule. I don't think it's nearly as critical as properly exposing the scene. The way I try to operate is to set the shutter speed as per the 180 degree rule, then get within one stop of my target exposure using an ND filter. Then, I adjust the shutter speed (in 1/3 stop increments) to hit exactly my desired target exposure. Often times, this means I'll have to have a shutter speed 1/3 or 2/3 of a stop faster than the 180 degree rule - or even sometimes one full stop faster, if I'm feeling too lazy to change the ND filter again. I think this is good enough for most situations. I think the problem with shutter speed usually comes into play when you're at least 2 stops faster than the 180 degree rule. So having a wide range of ND filters helps you get the granularity you need in this regard.

You should only raise ISO as a last resort. I only ever raise my ISO above 100 if, with no filter on, I can't get the 180 degree shutter speed or faster (for example, if shooting at 30 fps, I can't get 1/60 s or faster). Otherwise, you can accomplish the same thing by using a slower shutter speed. As for whether it's better to underexpose or use a higher ISO, I'm not really sure for the Mavic's camera in particular, but as a general rule, it's usually better to increase ISO in camera than to push shadows in post processing. This is the rule I apply to the Mavic.

Neat Video can help make flickering more subtle, but fundamentally it's not removing it - so it often isn't enough to remove all the visible flicker. Flicker Free is definitely a more effective tool for removing flicker. Sometimes I use just Flicker Free or just Neat Video, and sometimes I combine the two. It really depends on the scene, what profile settings I shot it at, and how well I was able to expose it. But yes, in some situations, using both at the same time does make a big difference - and gives a final output that's better overall than using either on their own (on neither). The way I go about this is, if there's enough noise in the clip to make me want to remove it, I first use Neat Video. Then, if there's still visible flickering, I'll add Flicker Free to the mix. When using both, I usually put Flicker Free as the first layer, and then add Neat Video on top of that (so that Neat Video is reducing the noise on the clip that's already had the flicker removed). If there's little noise in the original clip but there is flickering, I'll just use Flicker Free. Just understand that Flicker Free does have its limitations, and in many situations (mainly there are lots of moving components in the scene) it needs to be dialed back to avoid generating artefacts. In these situations, its usefulness is minimized - but it does still help.

And yeah, I really do think the Film Poets profiles made a huge difference for me (I have absolutely no affiliation with them, believe it or not!). I mean, there's no magic behind it - one could just generate really high quality custom profiles on their own - but I didn't want to go to the trouble of doing this, and frankly I don't think I could've done it as well as they did (BTW, I believe it was Neat Video who actually generated the profiles, working with the Film Poets to get the calibration images).

I don't think flicker is caused by not using ND filters. I think it's caused more by increasing the sharpness in the camera settings. For example, it seems to be worse when sharpness is at +1 compared to 0. It's complicated, but it's essentially a side-effect of the compression technique that DJI uses with the Mavic video. The problem that ND filters help with is to avoid having to use too high shutter speeds, which result in *choppy* footage.

Happy to help with whatever info I can. The Mavic is awesome, and it's a huge pain in the butt, both at the same time! Once you hit the magic settings, it can really produce some very decent footage. But getting it to hit the magic settings consistently in different situations is a big challenge!