Guerilla35, Any Updates??

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Barry_Green said:
I took a brief look at it, and I don't know exactly what it is either. I would initially have thought it had something to do with the adapter, because the flickering pattern seems to be somewhat round in shape, but it being a beta G35 would lend me to think that the adapter would have little or nothing to do with it. A static adapter wouldn't have a rotating ground glass, although a static adapter stopped down too far would cause the 'hot spot' syndrome of the center of the frame being brighter and the edges being darker in a circular pattern (not "vignetting" per se, as that's usually the frame actually being cut off, but this is related to vignetting). And we're definitely seeing that here.

But why should it flicker? Three potential scenarios suggest themselves:

1) it's the famous Premiere 1.5 flickering highlights bug? Did he use Premiere?

2) it could maybe be related to slowing down the footage for slow-mo, if data was leaping from one field to the other, but frankly that shouldn't happen on a white wall. Unless, as has been suggested, that it's due to the grain being visible on the edges of the adapter, and it's the grain that's leaping from field to field, causing the perception of flicker? But I doubt it.

3) My guess would be that if it's not caused by Premiere 1.5, then he had auto knee on. The auto knee can cause exactly this type of flickering on highlights, and a white wall would qualify.

This assumes that he's using a 50Hz camera with appropriate 50Hz lights; if he shot with 60Hz lights and a 50Hz camera, and then slowed that footage down by 50% in post, that could cause a similar circumstance, but I would assume from his general expertise that he wouldn't have committed such an obvious mistake. Whereas the auto knee is biting people left and right, and it's hidden in the menus so I expect that it's the more likely culprit.
dan said:
Rest assured, help is on the way. I PM-ed Barry (I don't think he noticed the thread) and he should be able to help us. Here it is:
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Barry,
I have noticed something unusual in Similo and I posted here:
http://www.dvxuser.com/V6/showthread.php?t=60437&page=6
Although many people have (or have used) the DVX camera, none of the assumptions could be explained or reproduced (imo) to match the unusual artifacts from that movie.
Do you mind to have a look at it and give us your opinion, please?
I am asking you as an expert with DVX, HVX being confident you should be able to see and identify the cause or at least point out what "can not be" out of all speculations.
Regards,
Dan Diaconu.
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mac/Miguel?
 
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Moving ground glass as it looks like its curves and we all know that can cause all of the above flickering ect.



but not if it was THE G35 we all know
 
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ASG said:
It was shot in Madrid and Lanzarote both 240V 50Hz power supply, PAL, 25fps.
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Barry_Green said:
If he shot with 60Hz lights and a 50Hz camera, and then slowed that footage down by 50% in post, that could cause a similar circumstance, but I would assume from his general expertise that he wouldn't have committed such an obvious mistake
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The end credits state it was shoot in Madrid, (a 50HZ zone). Where would one find 60HZ power in Madrid anyway? Is using a 60HZ power supply a "realistic scenario" (assuming you could find one in Madrid) ? Let's just say they found (and used) a 60 HZ power source.

How come in the room there is no flicker and outside (on the walls) there IS ! ( I am talking about the wide shoot from the hallway) Did they use 50HZ inside and 60Hz on the hallway in this shoot?

Is this a “realistic” possibility?
Let's just say they did (regardless how silly it may sound to some)
Did they switch from 50Hz lights inside/60Hz outside (on the wide) to 60Hz inside for the close-ups?

Is this a realistic scenario?
Let's just say they did go through all this trouble (don't make a bit of sense to me, but hey... film makers are by definition free spirits) and shooting “that kind of footage” may have lead to.... hmmm let's say “un-orthodox decisions” in regards to the power supply.

Well then, this means that I (or anyone else) should be able to get the same effect under the same circumstances, right? (I don't think I can though)

But that still does not explain the flicker outside (on the road) unrelated to artificial >>light<< (changed by me 7 hours latter from <<power>>).
Further; there is a circular moving specs of dust hard to ignore (one in the left bottom corner) moving "in sink" with the flicker.

Perhaps we should define first (and agree) on what is flicker?
imo, flicker is a variation in brightness. Some frames are brighter than others.

But this specific flicker has a "unique" look (to me). It looks like the corners of the frames show more flicker than the center. Further; old movies (hand crancked) do flicker, but that flicker is different. That flicker is NOT periodic, it could happen three times a second and then nothing for one second and... is EVEN for the whole frame (the whole frame got exposed more/or less\ than the average.
As opposed to this flicker which seems very consistent speed wise (but obviously out of sink with the frame rate of the camera)
Post your pro/cons please with any of the above (step by step). I will wait for a white flag before I give more hints.
 
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I think we can discount the power source since it's on outside shots and I've got it myself on outside shots. Barry Green's reply gave me an idea - what if it's down to video noise, worse in low light areas? It's just an idea but when you interpolate to create every other line maybe it's the nature of averaging where there's video noise that creates the flicker.

I'm convinced the flicker is caused by the deinterlacing somehow, it looks like it's flickering in sync with 25fps, i.e. every other frame is brighter.

The moving dust is either OIS left on or flexing of the adapter or cam (BTS shot shows no rails were used). From memory I wouldn't say the clip was long enough to say the dust was in sync with the flicker, I think they are unrelated. If it's OIS then as long as the camera is moving the OIS will amplify the movement because it corrects the flipped image in the wrong direction.
 
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I GOT IT!!!!!!!

Somebody accidently got just a pinch of their nail in the frame and it's confusing the lens OIS as to what is to be focused on. WOO HOO!!!!!!!

Dan, PM me for my address for those Lenses, you said a 1.4 50mm, right??

*Dodges Tomatoes*
 
ASG said:
Barry Green's reply gave me an idea - what if it's down to video noise, worse in low light areas?
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we already discussed that before. i'm pretty sure the video noise and adapter grain mixed with the 50i slowmo are linked to the flickering. when you look at the shoot where macgregor forgot the adapter (1:43), which had also been slowed down, there should be the same flickering if it was not linked to the adapter on. the flickering is almost in every adapter shot if you look carefully. inside, outside. not in the car. the car shoot is the only one which is not slowed down. and the adapter is on.
so it's the slowmo process which creates the flickering.
 
Ok enough speculation, here’s one of my own examples. It’s got nothing to do with the adapter, except maybe the light loss means you need gain hence more noise with the adapter.

http://files.filefront.com/flickerwmv/;5266241;;/fileinfo.html
(click continue to filefront)

An interlaced clip shot on a GS400 (no auto knee) slowed to 50% in vegas with smart resample so it does an interpolate deinterlace, compared to 50% speed with field double deinterlace done in virtualdub (I’m on dial up so I had to compress). I applied an extreme colour curve to emphasize the flicker. Look at the tree on the left. In the field doubling the noise and compression look worse but it’s not flickering like the interpolation does.

If I render the clip at 100% speed with interpolate it doesn’t flicker. Now here's something weird - if I render two clips at 100% speed one as upper field first with interpolate, one lower first with interpolate, then make a clip by alternating the frames from the two clips manually to get 50% speed, it doesn't flicker!!!

The flicker is caused by the way vegas renders at 50% speed with smart resample and interpolate deinterlace.
 
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Same shot better example:

http://files.filefront.com/flicker2wmv/;5268512;;/fileinfo.html

First clip is 50% speed rendered with interpolate deinterlace and force resample - flickers.

Second clip made by alternating frames from 2 clips rendered at 100% speed interpolate deinterlace, one upper field first and one lower field first - no flicker.

The flicker has nothing to do with power supply, frequency, autofocus, auto knee, the camcorder, the adapter, the compression - It's a software render glitch affecting Vegas 5, Vegas 6 and probably others (McG says he uses Vegas). I rest my case. :)
 
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Hahahahaha. What a funny post. It is so interesting how people tries to get how some shots were done.

If you wanted to hear my answer this is it. I DONT KNOW YET WHY THIS IS HAPPENING.

"The flicker has nothing to do with power supply, frequency, autofocus, auto knee, the camcorder, the adapter, the compression - It's a software render glitch".

That is the truth. It has nothing to do with the G35. I started watching this effect with HDV content months before shooting Similo (that is when i tought it was a HDV fault), but DV content has shown to have the same problem. Some areas flicker.

I tried to slow down the footage from the 50i source with other software but i got the same result, so i did not blame Vegas for the problem.

The betaG35 is static. Vignetting happens some times.

The dust spot moving in the wide bed shot is caused by reframing done in vegas (animated crop).
 
macgregor said:
Hahahahaha. What a funny post. It is so interesting how people tries to get how some shots were done.
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It was more about trying to solve the flicker issue for me, it's something that I've had problems with for a while - and I've found a solution now since it is eliminated by alternating frames from two renders (it's easy to set up a mask to do this with the two clips on the tracks below) - give it a try Miguel it works!

Haha - fake camera shake, no one guessed that. I want to know how you did the glowing light overlays. :)
 
I've only tried this once as shown on the clip I posted above but it seems to work.

Render your clip twice at 100% speed with interpolate deinterlace (or smart deinterlacer might give better res). Render once as lower field first, once as upper field first.

Create a project with three tracks, put generated media solid white on top track, one frame long, then copy it over and over so you have evey other frame white on the top track. Set composite mode to multiply mask.

On track two put the lower first render, parented to track one. Set the playback rate to 0.5 with disable resample.

On track three put the upper first rendered clip, one frame to the right. Set playback rate to 0.5 with disable resample.

Render this out as progressive with no deinterlace and it shouldn't flicker. It's a bit of a pain but you can save the project and you only need to do it on problematic clips.
 
VINGNETTING encroaching in the left corners like the ois is on would also make the dust move around or Maybe they zoomed out a bit also.

is this what dans Talking about maybe?
 
Ok. i understood what you said before. Thanks. I was thinking if there was a better way to do this.
In the end you are cutting frame by frame, that is too much work.
 
mike dawson said:
VINGNETTING encroaching in the left corners like the ois is on would also make the dust move around or Maybe they zoomed out a bit also.

is this what dans Talking about?
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The OIS was on only the 2 first days of shooting, wich are the shoots on the road (not the close ups in the end, which were done in a different location).

All the indoor shooting that was done with the G35 was done with the OIS off.
 
macgregor said:
Ok. i understood what you said before. Thanks. I was thinking if there was a better way to do this.
In the end you are cutting frame by frame, that is too much work.
Click to expand...


The only frame by frame cutting is to set up the solid white every other frame, and you can copy those in blocks and save the project so you only need to do it once. The rest is just a matter of 3 renders. It takes a few minutes to fix a clip, worth it if the flicker annoys you enough. I'm sure this could be automated but that is beyond me :)
 
Macgregor, thanks for posting.

Despite the fact that it seems like people are picking at a very, VERY small element of your film there is no denying that the movie is a great piece of work ( I haven't heard otherwise from anybody). I would like to say congratulations on such a great film.

As for the technical issues I only noticed a couple of things that I can still not define and they in no way detracted from the viewing experience. It will be interesting to see what the final consensus is as it's good to keep learning.

Best regards,

Jason
 
There is a zoom out on the dvx100 hence the VINGNETTING encroaching and the dust moving in towards the middle of frame.

I did that a few times doing hand held my thumb on the handle servo

Back me up guys.

Please
 
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