[HDR-CX405] Object Trail Problem

[bongocan]

Hi,

First of all my grammer is not well. I'm saying this because google didn't give me any site related to my issue. I think i can't explain it. So i am uploading an image to explain my problem.

The problem is, moving objects in the image (or when i move the cam) are leaving trails and make the footage so bad.

Here the picture of my problem: trail issue

As you see everything in the footage has a copy

Why am i having this issue and how can i resolve this.

Thanks in advance...

[IamNic · Accepted solution]

Hello @bongocan,

 there can be two reasons for that.

1. you film interlaced (e.g. 25i or 50i), meaning your sensor gets read out in two passes - first every odd number of pixel rows (1-3-5...1075-1077-1079), then every even row (2-4-6...1076-1078-1080).

I can't quite see it in the screenshot while viewing it on mobile, yet you would see it by the alternating lines in a still frame.

2. you expose at for a longe time than your current sensor read out happens. (Even though this should be blocked on consumer camcorders).

E.g. you film @ 25fps and expose at 1/12 (~twice the length of a video frame) of a second or longer.

This creates a very 'trippy' effect.

- Nic

[bongocan]

Well, i guess you are right i filmed in 50i. Tried to change that option to 50p first but camera warned me for something that i don't remember and i think it was related to quality (or file type). Warning was like this: "If you choose 50p you cant save file in xxx format type". So i'd left that option in 50i.

Thanks for your answer, it hadn't been a big deal then...

[IamNic]

Hello @bongocan,

thanks for getting back to me. 

- Nic

[darkframe]

Hi @bongocan,

---

@bongocan  schrieb:

Well, i guess you are right i filmed in 50i. Tried to change that option to 50p first but camera warned me for something that i don't remember and i think it was related to quality (or file type). Warning was like this: "If you choose 50p you cant save file in xxx format type". So i'd left that option in 50i.

---

well, the camera's manual is not too clear about that but as far as I see I do believe that the 50p option is only available at lower resolutions.

Obviously for e. g. FullHD (1920x1080) only 50i is available. 50p seems to be possible for HD resolution (1280x720). There's no information about the file format but, just a guess, I'd say that 1920x1080 leads to a M2TS, MTS or TS file (depends on the camera), whereas 1280x720 most likely leads to an MP4 file. Well, the file format is different but no big deal (there are other differences but explaining them here would be too much). The main difference is, that chaning to 1280x720 means a reduced resolution against 1920x1080. Just try which option serves you better.

Anyhow, what can you do? Nic explained the effects of the i (= interlaced) in 50i already. When playing back such a video on a TV you'll notice that you cannot see those double pictures anymore. However, a PC is working a bit different. Therefore most software which is meant to play back videos has got an option to "de-interlace" videos. When that option is active you won't see any more double pictures on your PC as well. Actually all of the playback software I know does it automatically.

Well, that's true until you stop playback. Then you'll notice too more or less different pictures at the same time. As said, the final video, when being played back on a TV, will look perfect nevertheless.

In case you like to produce a screenshot of a certain frame you need to load the clip into any modern video editing software. Most of those programmes will be able to produce a clean looking screenshot which might not be as crisp as it would be with 50p but finally better than having a doubled picture.

Cheers

darkframe