PolarPro- Filter Calculator App

[DodgeP]

Unless I'm just flat out using the app incorrectly.

 

[Kilrah]

OK, finally figured it out, it's not clear at all how it should be used.

For me "Shutter speed" was the target desired shutter speed, but no.

You're supposed to have exposure adjusted correctly, then tell it your ISO/SS and what filter is currently installed on the camera (to determine current illumination), and it will tell you what filter you should install instead to get a shutter speed of 1/(2x specified FPS).

I can do that easily myself (divide SS/ISO by 2 / increase ND strength by 2 until target ISO and SS reached), takes 10 times less time than taking phone out and entering data in the app.

Something that would measure ambient light before even powering the mavic up woud be much more useful...but alas the light meters in current phones don't allow for that.

 

[SkyHigh Pryo]

The current way I go about choosing a filter is (I1) is, start the bird, put in my camera settings, most often I'm using ISO 100, FHD, 60FPS, ShutterSpeed 120. I then point the camera to the sky and place filters over the lens until my sky or clouds has no zebra stripes.

With the method that I use, I can't see how the app could possibly work if the app doesn't somehow get a reading of the ambient light.

@DodgeP, what you said is very helpful to me. I am not into photography at all, so I kinda need a 'filters for dummies' help guide. Lol. I will admit when I dont know something and try get the help in figuring out the solution. Filters being one of them. [emoji17]

SkyHigh Pyro Eye flying above

 

[SkyHigh Pryo]

OK, finally figured it out, it's not clear at all how it should be used.

For me "Shutter speed" was the target desired shutter speed, but no.

You're supposed to have exposure adjusted correctly, then tell it your ISO/SS and what filter is currently installed on the camera (to determine current illumination), and it will tell you what filter you should install instead to get a shutter speed of 1/(2x specified FPS).

@Kilrah, thank you for putting that up. This is also helpful to me.

SkyHigh Pyro Eye flying above

 

[Kilrah]

I then point the camera to the sky and place filters over the lens until my sky or clouds has no zebra stripes.

This is not a proper method at all, zebras are completely unrelated and the sky isn't representative of your subject.
You should simply correctly expose a subject similar to what you're going to film and with the same light, then put the filter that results in th desired shutter speed.

 

[mwebster79]

Hoping to have my filters tomorrow. Will see how the settings in the Mavic compare with the Filter Calculator app.

 

[DodgeP]

This is not a proper method at all, zebras are completely unrelated and the sky isn't representative of your subject.
You should simply correctly expose a subject similar to what you're going to film and with the same light, then put the filter that results in th desired shutter speed.

It is almost impossible to correctly expose both a bright sky or bright blue sky with clouds and anything that "touches" it if you don't meter for the brightness of the sky. I actually have two examples of the practice that you claim is not proper. In most of my applications I'm using filters to knock down the brightness of the sky, not the brightness of objects. There are two constants (because I'm filming for slow motion) that I will always know before I ever lift off and they are; FPS and ShutterSpeed. In most cases we're talking 60/90/120FPS with corresponding 120/180/240 Shutter Speeds to match. In most cases I have an ND8 or ND16 installed to help with the sky.

You could run the footage through your video editing software and then correct exposure for both parts of the footage and use a graduated filter to blend the two parts to make one but why?

Exposed for the sky using my point at the sky method. Sky is good except at the horizon and so are the trees, building, etc. I could have masked off areas and made some adjustments but, meh!

Instagram video by Skies By EMG • Jul 2, 2016 at 2:44pm UTC

Cared less about the sky and simply metered for the bridge and the sky is all but gone.

Instagram video by Skies By EMG • May 20, 2016 at 4:20pm UTC

I prefer the look of the first to the look of the second because of course it's aerial footage.

 

[Kilrah]

In most of my applications I'm using filters to knock down the brightness of the sky, not the brightness of objects.

That's... just not how it works.
Unless it's a grad ND your filter knocks down the brightness of the entire image in the exact same way.

But from the rest of your post I now understand you set exposure manually - which is important but was not mentioned in your previous post. If you don't do that your method doesn't work. As you didn't mention it, someone who reads you without knowing (there are 90% chances they use auto exposure) will do a right mess and wreck his footage.

And my point was that the sky isn't always the brightest thing in a shot, which is why I said you shouldn't "expose for the sky", you should "expose for the subject you're going to shoot". That could include sky, and the sky being the brightest part, in which case you'd expose for the sky, but that's only one particular scenario and not a go-to method.

 

[Romi]

An overall "major step" type guide would be great.
And I'm afraid the selectors are way too small for my fat fingers!

 

[PolarPro]

Jeff, That would help, at least, me out allot. I really dont have much experience with filters at all, so something that would at least start in a basic direction would be great. Then it would be easier to plug the rest in to the shutter speed. Thank you for your reply back.

SkyHigh Pyro Eye flying above

Awesome thank you very much for the feedback!
Jeff

 

[PolarPro]

The current way I go about choosing a filter is (I1) is, start the bird, put in my camera settings, most often I'm using ISO 100, FHD, 60FPS, ShutterSpeed 120. I then point the camera to the sky and place filters over the lens until my sky or clouds has no zebra stripes.
With the method that I use, I can't see how the app could possibly work if the app doesn't somehow get a reading of the ambient light.

Our app uses info that you pull off the DJI GO app. You use the light meter in your aircraft's camera.
So in your case, before setting your shutter, you would set your camera to ISO 100, 60FPS, and see what the shutter speed defaults to for a balanced exposure.
Then plug those numbers into our app and it will kick out what filter brings your shutter to double frame rate.

Our app would provide you with an alternate method rather than having to swap through the filters.

Did you download the app? Any usability feedback?
Thanks!
Jeff

 

[PolarPro]

I have the app and I don't get any app any info if I don't plug in all 4 fields and then if I do plug in all fields the suggested filter is the same as the filter that I plugged in which I can't assume to be correct.

I would assume that the app would have to get an ambient light reading in order to suggest a filter for my settings.

The ambient light reading comes from the aircraft's camera. If you have a filter installed and your shutter is double frame rate, then thats the filter you should be using, and the app will tell you that.
Thanks for the feedback,

Jeff

 

[PolarPro]

An overall "major step" type guide would be great.
And I'm afraid the selectors are way too small for my fat fingers!

Hey Ron!
Can you elaborate what a major step guide would be?
Got the feedback on the selector buttons, will put that up on the design board!

Jeff

 

[Romi]

Hey Ron!
Can you elaborate what a major step guide would be?
Got the feedback on the selector buttons, will put that up on the design board!

Jeff

Jeff, it took me a little while to figure out what to do, but I did figure it out so maybe it's not necessary.
However, what I meant was a high-level guide or description of what to do and what the results mean. I'm not as versed in what the filters can do for me and using your tool is very helpful. With so many drones being sold I'm sure there are a lot more like me out there who could benefit from your app and learn to use filters properly.

 

[Rom3oDelta7]

@PolarPro, lots of discussion here but my main suggestion is to add a proper help page that explains what he user should do and what the app calculates, none of which is present today. Seems like this is mostly for folks who aren't familiar with exposure calculations and perhaps people like me who are but could use this app as a shortcut/convenience (my phone is already out and controlling the drone, might as well just quickly switch to make sure I didn't mess up the math I would do in my head - it's happened before ).

 

[daithi23]

Automatic updating as you change values would be good.
Some direction on how to use the app (I figured it out but it'd definitely help)
Some more information on what each filter does would be good for beginners to learn from.
This info doesn't need to clutter up the main app screen for more experienced users but on a separate help page or optional mini-tutorial when users first start the app.
Also, sometimes when I open it my last values are gone and it resets to 24FPS, SS 1 so have to change these. I never use 24FPS so I can see it becoming a bit of a pain changing it every time.

Sent from my SM-G935F using MavicPilots mobile app

 

[Gludy]

The current way I go about choosing a filter is (I1) is, start the bird, put in my camera settings, most often I'm using ISO 100, FHD, 60FPS, ShutterSpeed 120. I then point the camera to the sky and place filters over the lens until my sky or clouds has no zebra stripes.

With the method that I use, I can't see how the app could possibly work if the app doesn't somehow get a reading of the ambient light.

 

[Gludy]

Well dam, totally confused by the save the filter option nor can I get the app to work as its just states the filter I have entered after I press calculate.
Hleo!

 

[Hugabeen]

I received my 6 Pack on Monday. the filters work wonderfully. But the thickness of the housing won't allow for start up and calibration with the filters installed. And they're super hard to remove carefully. Any suggestions or hacks to make this easier?

 

[roberto]

Quick question, is it possible to grab the exposure data through the DJI SDK? I've got to have my phone connected to the craft to get the data, and I'm going to switch to the calc to transfer the data I see in DJI Go app... But if it's connected can we just query the craft for the current exposure? Camera - DJI Mobile SDK Documentation

If so then it would be awesome if I could get the exposure I like, switch to the calc, see which filter to attach, and confirm. Then have the calc manually set the exposure for the frame rate I'm after on the craft.


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