A puzzling oddity

Patrick Cooper · January 25, 2016

Ive just about completed a film that I'm going to submit to some film festivals. The final two shots are time lapse shots with a dissolve between them. The second to last shot is of a sunset which naturally fades to black because of the decreasing light levels. The very last shot is a time lapse of stars rotating over the crest of a hill. Playing this sequence back on my pc, I'm happy with the timing in the editing. The stars start to appear after a very brief period of blackness. However, playing it back on a tv this afternoon, the timing seems quite different. The period of blackness between the sunset and the stars appears noticeably longer. And it's not a slight difference. It's actually too long for my liking and looks a bit clumsy.

I'm puzzled about what's causing this difference. And by the way, it is exactly the same file that was played on both display devices. My computer monitor is not properly calibrated - I'm not sure if that has anything to do with it. My query is - if my film is selected for screening at festivals, are people going to see the brief period of blackness between these two shots that I carefully adjusted on the timeline in my NLE or are they going to see the awkwardly long blackness that I see when I play back the file on the tv in my living room? I guess no one can really say with any certainty at this point in time.

Patrick Cooper · January 26, 2016

I guess it just simply must be that the tv is set brighter or more contrasty compared to the pc. Today, I played the film on a laptop and another tv and did not have the same issue.

Phil Rhodes · January 26, 2016

It may be.

It may also be a luminance encoding issue - are you using the same playback software on each?

A wide variety of problems can occur with regard to the choice of some software to encode luminance in a 16-235 code value range, and others to assume it was 0-255. Unfortunately this is often not very well signalled in the file, and as you'll appreciate, it's too easy for blacks and whites to be clipped, crushed, or sat-up improperly. It is a complex problem and can be hard to solve.

P

Patrick Cooper · January 26, 2016

Both the pc and the laptop were using Windows Media Player. However, Ive no idea what the tvs were using. By the way, they were cheap Kogan HDTVs with my external hard drive plugged directly into them. Actually on one of the tvs, the brightness had been set a little high and that allowed me to see a fault that I had not noticed before. There's a very brief clip which is meant to be pure black but I could just make out some visible text on the screen, albeit very faint. Ive since fixed that.

Phil Rhodes · January 26, 2016

Can you make the file available?

Patrick Cooper · January 26, 2016

Yea I could upload the final two shots (and the dissolve) to youtube or vimeo.

Phil Rhodes · January 26, 2016

Problem with that is, they'll get converted again by the website, and introduce yet another variable...

Patrick Cooper · January 27, 2016

Ah....what would be some other options for making the file available online? Ive tried Dropbox just once (to upload a video) and the upload failed. I tried multiple times with the same result. Would Google Drive be viable? I'm yet to try that one.