False frame rates and a genius down under

[dwight]

Turns out a certain Australian troofer has discovered anomilies in the frame rates on the Apollo 11 TV feed. Not 30 fps as long claimed by NASA, but 24 as his in depth analytical research uncovered. "Eureka!" one might claim until they delve a little further and discover that the DVD purchased is actually a PAL converted version of an NTSC video.

Congratulations. A stunning piece of detective work there.

[Zakalwe]

 

Im sure that the next step will be another "in-depth" YT video ranting about how the DVD distributors and producers are all in on the "act" and are nothing more than paid shills.

[Luke Pemberton]

"Eureka!" one might claim until they delve a little further and discover that the DVD purchased is actually a PAL converted version of an NTSC video.

Can you explain this a little more, and how it debunks said twoofer's analysis. Film conversion and video rates is really not my forte, and I'd be interested to know.

[ka9q]

It's my impression that most of the Apollo TV footage was archived on film rather than videotape, and that's why it appears to be 24 fps vs the 30 fps (or 29.97 fps) of the US-standard NTSC cameras used.

I live in a (former) NTSC country and have done TV broadcast engineering so I'm very familiar with 3:2 pulldown. I've never worked with PAL, but my understanding is that it's 25 fps, not 24, and because those numbers have no common factors the usual practice is to simply ignore the small difference when converting film to video. Is that true?

[dwight]

True, PAL is 25 fps. The restored A11 TV feed is sourced from NTSC videotape held in CBS and the VHS of Sydney video (also video sourced). The 24 is from said genius' counting. Given GOP and all the other inherent MPEG2 encoding paramaters, using that transport stream as a robust method to calculate analgue video framerates isn't exactly the smartest thing to do, especially in the presence of people who actually use such files professionally. It is similar to claiming jpeg artifacts constitute alien structures on the moon. These days it is possible to encode in 24p, but the PAL DVDs are stock standard 576i encoded. I bet our mate doesn't even know the said DVDs were converted using Atlantis DV film which clearly states on it's website that "NTSC to PAL works by first converting the NTSC to film motion (24P), same as with DVFilm Maker, then speeding that up slightly to 25P." And there, my friends, is where the 24 frames come from.

The whipper-snapper seems to have adopted the tried and true "If I can't baffle them with brains, I'll baffle them with b.s." motto. His video analysis of Apollo TV lacks any sort of proper research, nor any great understanding of TV technology in general - as usual.

[Luke Pemberton]

His video analysis of Apollo TV lacks any sort of proper research, nor any great understanding of TV technology in general - as usual.

Thanks. So basically he's forgot to account for conversion between various formats and made the erroneous conclusion that the film rate observed in the archived version does not match the equipment NASA claimed they used to film the footage on the moon. It's a bit like the underpants gnomes in Southpark.

• Dodgy film rate
• ??
• NASA conspiracy

Face palm again! I think this sums up another hoax argument. Find evidence that meets one's preconceived ideas and then present evidence for a hoax without really trying to find alternative explanations first.

If some of the hoax believers actually spent the same time investigating the 'reported' version of events as the people unraveling their claims... sigh, I give up venting my spleen.

[dwight]

Exactly. Before I go around telling everyone "the butler did it" I tend to make damn sure there was actually a butler present.

[ka9q]

So I was correct in my understanding that PAL simply punts on the slight difference between 24 fps and 25 fps?

Speaking of "a. I don't understand something, therefore b. NASA hoax!", this seems to be the argument of those who've found the "smoking gun": the Adobe Photoshop signature in the readily available scans of Apollo photography. Sheesh.

[Glom]

Are there some who actually argue Adobe Photoshop was used to fake the photos decades before it was written? I've always assumed talking about Photoshop was just a generic expression for using a tool to manipulate images.

[Obviousman]

Who is the "genius"? I'm a little bored right now.

[Allan F]

Jarrah White. Look him up on youtube.

[smartcooky]

It's my impression that most of the Apollo TV footage was archived on film rather than videotape, and that's why it appears to be 24 fps vs the 30 fps (or 29.97 fps) of the US-standard NTSC cameras used.

I live in a (former) NTSC country and have done TV broadcast engineering so I'm very familiar with 3:2 pulldown. I've never worked with PAL, but my understanding is that it's 25 fps, not 24, and because those numbers have no common factors the usual practice is to simply ignore the small difference when converting film to video. Is that true?

This brings back a memory for me. Do NTSC and PAL not have the same Hscan frequency, 15625 KHz?

PAL uses 625 lines/frame which yields a frame rate of 15625/625 = 25 fps
NTSC uses 525 lines/frame which yields a frame rate of 15625/525 = 29.7 fps

[raven]

How do you get a fractional frame per second? 

[Al Johnston]

Easy: 100 frames per minute is fractional per second...

[raven]

So it's the average then, because how do you display a fraction of a frame?
That's really what I was asking.