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ND filter experts wanted

Discussion in 'Pro/Adv Discussion' started by Karanba, Jun 19, 2016.

  1. Karanba

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    I have started using ND filters, for now ND8, more to come. Logically those filters give gray film on all videos. How to remove that? It goes off with contrast or exposure increase ? I dont have brightness option in GoPro Studio.

    Thanks
     
  2. Karanba

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    Just compared my Auto setting video without ND filter and Manual with ND8 filter, without filter it has so much more color and it is a lot clearer ! Why the hell should we use those ND filters at all then ? What am I doing wrong, this ND filter simply takes like 50% of the vibrant colors from the video.
     
  3. alokbhargava

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    List out all other settings you are using for the videos. Nd filters definitely reduce light to sensor few fold times as that's the purpose.
     
  4. Karanba

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    Ok, here it goes :

    ISO 100
    1080p 30fps
    Shutter speed 1/60 sec
    D-Log color
    -2 sharpness
    -3 contrast
    -2 color
    ND8 filter

    It simply cannot "see" strong colors,
    like bright green grass or trees. Like I am watching trough sunglasses, simply color isnt there. Whole video is dull, I know that it suppose to be that way from the camera but lets say green sugarbeet leef can be dull green or bright yellow-green, it is impossible to get real full vivid green color. I can even understand why, ND filters are so dark, it cannot see real colors but I was sure that there is some trick with those ND glasses but there isnt, it simply cannot record color like without filter. I am no pro in post but I have managed to get good results from GoPro and stock Phantom 3 camera in GoPro Studio so I know basics.

    Videos with ND filter are like watching them on old plasma screens which cannot get bright enough to show picture right. I know that I am not able to tell or see bright color with my sunglasses on. I am so disaapointed, I hope that I am missing something. I dont want my noon sunny days become cloudy days on the videos.
     
    #4 Karanba, Jun 19, 2016
    Last edited: Jun 19, 2016
  5. snerd

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    Using D-Log with the turned-down settings will result in a very "flat" image. You have to post-process most d-log videos in a separate program to get the appearance back.
     
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  6. Susruth

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    With ND filters for videos you certainly need to put them on post production
     
  7. Susruth

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    As snerd rightly said
     
  8. Karanba

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    Yes I know but I have played with exposure and contrast in GoPro Studio but still I dont get strong vivid colors like I want. MAYBE my ND8 is too weak for sunny day and with all those manual settings. I think I have too much overexposure. Here are some samples. on low flight photo I can make pretty good result but from above it it impossible to get green color and all other. 1st is good and second and especially those when Phantom is facing the sun but camera is completely on the ground are terrible. Is that ND too weak ? I should try ND16 ?

    [​IMG]

    [​IMG]
     
  9. Karanba

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    1st photo is from 3m height and it can get very good color, other 2 are from 20-30m and I cannot get anything like that in that part of the video. And funny thing is that in 1st photo I have sky which ups EV and on other two I have only ground. Any thoughts ?

    [​IMG]

    [​IMG]

    [​IMG]
     
  10. olof Ekbergh

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    Here are 4 versions using ColorFinale in FCXP.

    1. Raw file from P3P shot in D-log with reduced contrast and sat. With ND8 filter 1/100 iso100

    2. Corrected by lowering blacks and raising highlights and slight saturation and a 30% use of a Fuji film LUT for REC 709.

    3. More contrast and sat as well as a Kodak film LUT for Rec 709, a bit over done.

    4. Very overdone Kodak film LUT for Slog full strength.

    Adding a ND filter does not alter contrast at all it only lowers the amount of light that hits the imager, normally this is done in video cameras by an internal set of ND filters.

    The 3 looks I added in post shows you can pretty much make it look any way you want. I always expose manually in the P3P I use the histogram to make sure exposure is correct. I use ND 8 or 16 and I try to get 1/60, 1/80 or 1/100 shutter speed for 30p. NEVER USE AUTO EXPOSURE it will ruin your shots most of the time by changing as the frame changes, nothing yells amateur video more than exposure hunting.

    Using vector scope and wave form monitor will help you CC/grade your shots. It is a craft as well as an art and a very important part of video production. Take a course in CC (Color Correction) and Grading and you will learn how it is done. It is a very large subject involving a lot of different tools and prebuilt LUTs. ColorGradingCentral.com is a great place to start.

    Have fun!

    Screen Shot 2016-06-19 at 15.17.34.jpg
    Screen Shot 2016-06-19 at 15.17.57.jpg Screen Shot 2016-06-19 at 15.18.59.jpg Screen Shot 2016-06-19 at 15.20.47.jpg
     
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  11. Karanba

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    Yours look good even with stock, why are my videos with gray film ?

    Also, where is the Auto Exposure setting ? It goes by itself when I fly in Manual mode, ISO is on 100, shutter is on double the framerate but I dont know how to manually tune exposure ? I want to be on 0 or max -1.0 EV but it moves by itself. Is it smart to fix the exposure because it needs to adjust on the fly ?

    EDIT: I see now that I can choose Auto mode and adjust the EV or Manual mode and adjust ISO and Shutter speed. Which one is better to use then with ND filters ? Everyone is telling to go Manual mode and now it seems that you think that it is better to put ND filter and fly on Auto with manual EV setting, so I need to push it always to be on 0 or close to that ?

    Thanks
     
    #11 Karanba, Jun 19, 2016
    Last edited: Jun 19, 2016
  12. olof Ekbergh

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    There is a setting to use either Auto or Manual in the Camera menu. In manual you can set shutter speed and iso (always have iso as low as possible or you will get nose/grain). Read up on how to use histograms for exposure, lots of info on the WEB about this. Basically keep most of the peaks in the middle, not bunched left or right (this is very simplified, read up on it and practice a lot.

    You have to read the manual.

    Depending on the scene you are shooting, it may look dull with lower sat and contrast and Dlog settings. The shot I used was pretty contrasty and sunny to start, this is a good scene to shoot in log. A dull scene will definitely need help, and you may be better off setting a different mode and increasing contrast and saturation in the camera. This is especially true with highly compressed cams such as the P3P, this is called "baking in a look". Log really needs a better codec. But I will say the the Dlog is not very "loggy" if I can use that term, it is quite mild, more like a hyper gamma curve really, you can read up on those terms as well on the WEB.

    I have 40 years in the film industry so to me this is all obvious stuff I deal with every day. Video/Photography are huge subjects and it takes years to learn even a small part of the trade. In pro settings there is specific training for all the parts of production. Shooting, editing and grading are 3 of them not to mention writing, directing, lighting, continuity, scouting, location management, security, finance etc. etc..

    So trying to master all this as an amateur is a big job. Starting by understanding exactly how your camera works and how to set it up for different shooting scenarios is a great start. It begins by reading your manual and then experimenting a lot.

    One thing that will help you set your camera up correctly is to install the HDMI module on the TX and hook up a good calibrated monitor to it and just point the P3P camera at a typical scene just on the ground, and then play around with the settings and exposure until it looks good on the evaluation monitor. And at the same time take note of how the histogram looks.

    Just keep working at it, experiment and you will get better.

    One last bit of advice is use a good grade ND filter and keep the lens and ND clean, and be very careful of how you do this so you don't damage the glass. A blower and a lens pen is what I use, and as a last resort a microfiber lens cloth. Also get a lens cap to keep the lens clean in transport.

    But most of all have fun and be safe.
     
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  13. Karanba

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    I dont need perfect videos, I am just hobby user.
    Do you then mount ND filter and put camera on Auto and then put EV on 0 with right wheel when recording ? I will try that also when I get my Neewer filters. I will put filter which will go to max 1/100 shutter and low ISO.

    When you say never use auto exposure then you make videos on Auto and ND filters. That way could also be better for me since I record on the field in all directions.
     
  14. SnoozeDoggyDog

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    Are you in the uk?
     
  15. Karanba

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    Nope. Why ? Any ideas regarding topic ? :)
     
  16. SnoozeDoggyDog

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    I do not have anything to add sorry, I'm a learning amature. I was just going to say if you are in the uk our lighting levels are different from those in the USA. I've recently bought the taco-rc nd's but have yet to use them in anger .....
     
  17. olof Ekbergh

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    I always use manual on all my cameras including the one on the P3P, it is easy to adjust exposure as you change the shot. Just stop and set the histogram so it looks right for each angle, on the P3P cam you can only change the ND or the shutter speed or the iso, so it is a bit harder, sometimes you have to compromise. But as I said nothing looks more amateurish than a constantly changing exposure, even on a long pan shot. It looks bad as the sky changes value.
     
  18. Mako79

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    What does your video look like without the ND filter? Could it be your camera?
    It may be a faulty ND filter (not sure how)? Do you have an ND16 you can test with??
     
  19. WetDog

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    I'm not sure that Olof's suggestion to avoid auto exposure is a good one for an amateur photog. Yes, exposure hunting looks horrid but you can avoid that by waiting until the exposure settles AND by flying slow. It just depends on how well you can set up your shoot. A pro is going to spend hours going back and forth, understanding exactly what it is they're shooting and what the director wants.

    Us amateurs, not so much.

    But the advice about the histograms is spot on. And the annoyance of the D-log is true although there really isn't a whole lot better option with the P3.

    One thing that hasn't been asked is what ND filters you used. They should most definitely NOT impart a 'gray' anything to the scene. That's why they are called 'neutral'. Crappy filters abound. And there are ND - polarizer combos which are really tricky to use. As has been mentioned, take the filter off and see what you get. The whole point of an ND filter in video is to get the shutter speed down to where panning looks 'normal' (ie, like film). It should not do anything else.

    A 'gray' film to a scene is usually low contrast. That can only be 'fixed' in post but you can help by looking at the scene before you film, making sure you are not pointing the camera into the sun and making sure the lens is very, very clean.
     
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  20. Karanba

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    I have used ND8 and it looks like it should be ND16 so the green sugarbeet has all the color, now it has like water shine white on it from the above and I cannot get anything from it in post. I manage to get rid of the gray in post by increasing contrast. And it looks good for low fly video here but from the above the video simply does not have color, it is too bright I guess.

    I dont get you guys who say that you work in manual mode and then you say that you change the exposure. I cannot change exposure in manual mode, only in Auto.

    So when you go in manual mode you change ISO in order to get the EV to 0 ?