4k crop and zoom for stills.

SnoozeDoggyDog · Jul 23, 2015

Hi
Can anyone please help me? What is the detail attainable from a still taken from a grab of 4k footage. I only have a p3a so can't test myself.

Eg, I'm looking for a missing person and I'm at an altitude of 200ft. I take 4k video of an area. I play it back and take a screen grab. What is the detail when zooming into the captured still?

If anyone could provide me with examples to a gdrive/Dropbox that would be fantastic.

Thanks

Meta4 · Jul 23, 2015

If you use software to extract a still from 4K video it is 8MP as against the 12MP you get for a still.
If you just get a screen shot, that will depend on your video card resolution but will be much less - probably 2MP or so.

SnoozeDoggyDog · Jul 23, 2015

Meta4 said:
If you use software to extract a still from 4K video it is 8MP as against the 12MP you get for a still.
If you just get a screen shot, that will depend on your video card resolution but will be much less - probably 2MP or so.

Ah OK, that answered things. Thanks. In that case I'll do some stills testing with my p3. Thanks.

Phil

taroh · Jul 23, 2015

Crop from wide angle pics, be careful to perspective correction (unless you zoom into the center). Since the edge of the picture distorts, simply crop a part won't be the same as zoom. Photoshop (still) or Premiere (footage) have perspective correction, as many other post process softwares.

jadebox · Jul 23, 2015

Note also that video tends to be captured with a lower shutter speed so there's more motion blur. Stills captured from video are never as good as real stills. Having said that, though, I've taken stills from 4K video that look pretty good. For most uses, especially displaying on the web, they are fine.

-- Roger

SnoozeDoggyDog · Jul 23, 2015

Thanks for the replies. I was asking mainly about stills from 4k movie footage as I may capture something on video that isn't always noticeable to frame a still for. But if stills are the best way to go then I'll have to rethink. Hopefully Litchi will be able to develop a compatible p3a version after the firmware release. Time lapse stills might be my better option.

Opman711 · Jul 23, 2015

ImageUploadedByPhantomPilots1437675928.131640.jpg

I was able to get this screen capture from video shot in 4k. I'm pretty impressed with the quality. Keep in mind the actual quality is better than what is uploaded to the forum.

jadebox · Jul 23, 2015

SnoozeDoggyDog said:
Thanks for the replies. I was asking mainly about stills from 4k movie footage as I may capture something on video that isn't always noticeable to frame a still for. But if stills are the best way to go then I'll have to rethink. Hopefully Litchi will be able to develop a compatible p3a version after the firmware release. Time lapse stills might be my better option.

A lot of it depends on specifically what you are trying to capture. I've been recording model rocket and high-power rocket launches. I can usually get nice stills using the "burst mode" which takes multiple images quickly. But, I can always get nice video of the launches.

I try to mix it up - capturing videos and stills. Sometimes, I'll extract stills from the video and, often, I will use the stills in videos I produce. It's really nice to be able to control the camera and choose what you want to do while the 'copter is in the air!

-- Roger

SnoozeDoggyDog · Jul 23, 2015

I'll get out and do some testing tonight shooting stills. It certainly looks great quality stills taken from 4k.

SnoozeDoggyDog · Jul 23, 2015

Is it just me or is there no burst mode on the P3A?I can't find it in the settings?! My P2V+ had it!

SnoozeDoggyDog · Jul 23, 2015

Don't worry, found it. Thanks

Dave Ward · Jul 23, 2015

One thing to keep in mind about video stills vs. photos is shutter speed. In good light, video will ideally have a much longer shutter speed than stills, to blur one frame into the next. If a sharp still is important, using the photo mode will produce much better results than a still capture from a video.

4wd · Jul 23, 2015

They are quite good, most people would never realise it was not taken as a jpg.
This is a screen grab taken viewing 4K file in VLC player.
Original was about 8MB

SnoozeDoggyDog · Jul 23, 2015

4wd said:
They are quite good, most people would never realise it was not taken as a jpg.
This is a screen grab taken viewing 4K file in VLC player.
Original was about 8MB

God! My still aren't as good as your still from video! I'm really struggling. I've been out tonight and binned everything I've snapped. Fuzzy rubbish. I really really need to hit the camera specific threads.

SnoozeDoggyDog · Jul 23, 2015

SnoozeDoggyDog said:
God! My still aren't as good as your still from video! I'm really struggling. I've been out tonight and binned everything I've snapped. Fuzzy rubbish. I really really need to hit the camera specific threads.

Lol just realised you said it's a jpg from 4k grab ... that's even more depressing. I've been shooting raw all night

Dave Ward · Jul 23, 2015

It's quite a bit harder to get good photos (or video) at night vs. day. Your exposure time is going to be longer at night and much more prone to blurry results if the Phantom moves a bit during the exposure.

At night, the key for me has been to wait until the h/s and v/s indicators in the Pilot app have been at 0.0 for a couple seconds before hitting the button to take a photo. The gimbal is so good that it can seem like the view is stationary while the Phantom is still slightly drifting to a stop.