D90 Live View and Video Questions

Discussion in 'Nikon' started by bikealps, Mar 2, 2014.

  1. I need to take a video of someone talking, seated at a table, in a cafeteria, so I'm doing a practice run at home. I have a D90, tripod, and a Rode microphone. I'm using a 50 f1.4 lens. I have good selection of lenses to choose from.
    My dry run looks ok except that the video looks like it was shot wide open (background blur matches stills at f1.4) and the focus isn't quite dead on. My subject moves a bit. I think I need to shoot at f2.8 or f4 to get some practical depth of field.
    If I shoot at f1.4 ISO 800 I get 1/60. Shutter speed increases as I stop down in still mode, but I'm not sure what's happening in live view/video.
    How can I set f stop in video mode?
    And a few other questions:
    • grain --a D90 gets pretty grainy for stills at ISO 800, but the room I'll be in is just window light. What's a reasonable limit for ISO in video mode? It seems like grain isn't such a big deal because video is a sequence of frames.
    • shutter speed -- video must have a limit on "shutter speed." Hmm... in live view there is no shutter, so what's going on?
    • aperture -- if I want to get a subject "in focus" while they are speaking, what f stop do I need? I'll have them be relatively still.
    I know people can take decent videos indoors on point-and-shoots with tiny sensors, so it seems that I should have no problem with my D90... but why can't I control aperture? is there a setting I'm missing?
     
  2. I think I have an answer for my own question. to shoot video, the exposure time has to be less than 1 over the frame rate. With a frame rate of 24 fps, the maximum exposure time is thus 1/30s. For my test shot, I did not have enough light.
    But the camera fooled me because it still states an exposure time. Instead, it is not allowing me to stop down.
    So I need to try this again with more light.
    And a year ago I shot some stills in the room I will shooting in. At ISO 200 and f1.4 I got 1/1000s. In that case I can do f4 at 1/60s and be ok.
    Any guidance on the maximum usable ISO for video on a D90? ISO 200 is the base. I'm assuming ISO 800 won't be too bad, considering you only get 1280x760 pixels vs. still resolution of 4288x2848 pixels.
    I'm surprised the camera didn't warn me or inform me better.
     
  3. Video with the D90 is very limited in its ability and quality. Do not pan (or if you do, do it very, very slowly).\
    A sort of work around would be to use a different lens that has a slower aperture.
    You may find this of interest. #3 has an answer to the setting questions:
    http://www.dummies.com/how-to/content/how-to-record-video-with-a-nikon-d90.html
    Decent HD video cameras are very inexpensive. Not sure what type of event this is but it may be worthwhile getting one.
     
  4. If the person is seated and the camera is on a tripod, focus manually. Set the exposure to manual (I'm assuming the camera lets you do this in video mode) and get the aperture down to maybe f/8 to give yourself some depth of field -- being in focus is more important than having pretty bokeh. If there's not enough light to get f/8, move closer to the window, or use a light.

    You didn't mention which model Rode mike, but for this type of shot you want a lapel mike clipped to the subject's tie/collar/shirt. If you have the microphone on the camera you're not going to get good sound as good as you will get with the mike on the subject.
     
  5. Of course, you must be recording the audio somewhere else, as the D90 has no audio input for the mike.

    I agree that the D90 is really limited in it's video capabilities. Set your exposure manually though, and it should hold.
    imho, ISO 800 is fine for video on that camera IF you have enough light. If you're underexposing, you'll have noise. Period.
     
  6. "But the camera fooled me because it still states an exposure time. Instead, it is not allowing me to stop down."​
    Just keep in mind that with D90, you cannot change the aperture AFTER you enter live view. You need to meter, set the shutter speed according to the frame rate, f2.8 or 3.5, based on the DOF, and then let the camera picks the ISO before entering live view. If your lens has an aperture ring, then you could change the aperture manually in live view. The video compression in the D90 is rather cruel which is another factor that degrades the video quality. Is 50 mm the only lens you have? You can try a wider lens which has more DOF (so to speak) at a given aperture.
     
  7. Given all the video limitations with the D90, have you considered shooting with a camcorder? Everybody seems to love shooting video with a DSLR these days. But I've shot professional video in addition to professional stills, and IMHO just about any mid-level camcorder eliminates the problems that typically crop up with DSLR video.

    The absence of a microphone input on the D90 (Thanks Peter -- I was not aware of that) puts it in the category of the cheapest consumer camcorders meant for home movies, not serious work. Yes you can shoot "double system" sound and there are situations where that is preferable, but being required to shoot double system sets you back more than 50 years in the evolution of movie/video technology. (Double-system has always been the standard for shooting with movie film. But for video, sound was recorded on the tape alongside the video signal from the beginning in the late 50s. Video cameras still record high quality digital sound along with the picture now that they've moved to memory cards. Single system shooting was also standard for TV news on 16mm film from the 1950s until video took over in the 70s/80s.)
     
  8. Thanks for the info on setting aperture. I think that solves my problem.
    I think the D90 will be suitable for my purposes. Besides, I already own it, so it's free.
    And the D90 does indeed have both an internal microphone and a microphone input. From my test shots, the Rode microphone is much more directional than the internal microphone (doesn't pick up background noise) and also doesn't pick up camera noise. I think it'll do well or my purposes.
     

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