noticed waves in footage

Cees Mutsaers

Cees Mutsaers

Veteran
Today I noticed something very strange I never saw before. When I zoom in completely I see a wave in the footage. Has anyone seen this before??????
What about the sharpness of the footage at fully zoom, wide and in between ? (yes white balance is not good but not important at the moment). Backfocus is yesterday optimised at the dealer using a 25 inch HD Panasonic broadcast monitor connected via HDSDI.


http://www.youtube.com/watch?v=Pt2d1Ah4XsA
 
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Hi, were you filming from inside a property by any chance as that looks awfully like heat haze. if you were say filming through an open door or window then the escaping heat from the room would cause that effect.
 
Hi Garion, That is really a good one, I indeed opened the terras doors to film because i did not want to film through glass, very stupid of me not to think about that possibility of heat flows. I will film the same shot again tomorrow through the glass just to see if it is gone than. What did you think about the sharpness at the various zoom stages? As mentioned in the begining the backfocus was set at the dealer (yesterday) using a professional 25" Panasonic broadcast monitor (via HDSDI connection) so it should be ok (and to be honest I think it was already ok but I wanted to rull out this parameter).

Thanks for your comment :-)
 
Yes i looked again and to me its definately heat escaping from your room distorting the image, it is also slightly softening the image a little.. Bit like when you see the jet exhaust off the back
of a jet fighter, you see the ripples in the air..

Ideally (especially if its cold where you are) you need the camera outside and aclimatised to the outside temperature to help stop this, your image looked fine fully in and to me it seemed a little
sharper at the mid point? (could be my eyes tho). Fully out it was probably affected by the escaping warm air from the room as it was very slightly softer but then again its late here in ol england am i am a little tired :)
 
Agree, its just heat. Used to have this problem shooting in Tokyo a lot, esp. at night. Cold air everywhere and heat coming up from subways, sewers etc would cause this nearly always on longer shots.
 
Thanks everyone for your comments, I can sleep now since you all agree it is just the heat flow :-)))

Concerning sharpness do you think it is according to spec ? I still have the feeling that the images is soft especially in wide shots.
 
The sharpness looks fine to me now and even at 360p it looks closer to what I get.

Bear in mind you tube will compress more than the raw footage but it looks fine to me, softness in wide shots may be down to the lens but what do you expect from a camera and lens at this price.

I have taken to shooting AVC i 100 720p for amy web based material as this seems to be best for web delivery and the same format I use for delivery to you tube anyway.
 
"I have taken to shooting AVC i 100 720p for amy web based material" but you still record at 1080/25p and than down convert to 720/25p ???
 
Hi Cees
i think you have to keep the detail coring in lower values.
+5 or +2 (http://www.dvxuser.com/V6/showthread.php?225702-I-can-not-get-HD-out-of-the-HPX300) may be too high for a sharp look: they make image softer.
0 (zero) isn't "off" detail coring, it is the middle value in detail coring range (-7/+7)
more coring=more softness (less noise)
less coring= less softness (more noise)
In theory, we get the maximum sharpness (and the maximum noise, unfortunately) with:
detail level +7
detail coring -7
(i think, but i could be wrong)
you might try if you want
and you could tell us the test results
(sorry my english: i'm using Traslate Google for "a little help")

good life to everyone!

Umbit
 
I used to shoot 1080i 25p all the time but a couple of jobs recently were designed for web streaming as they had over-cranking involved so to get more storage space and do this I had to shot them at 720p.
 
Hi Umbit,

ok good tip I will turn the detail corning further down. The reason I put it on higher value was that I wanted to increase the sharpness by increasing the "detail level" but i did not want extra noise so that is why i increased the detail corning as well not knowing that the impact on the sharpness is so high. Which value do you use for the combination "detail level" , "V detail" and "Detail corning" ?
 
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Hi Umbit,

I decreased the detail corning to "0" and it helps, from the Barry's "The HVX book" I understand that at "-2" the softening (reduction of noise) is minimal (don't know for sure if it is the same for the HPX). Next project I will use the following settings :

detail level +1
V detail level +2
detail corning -2
f between open and 4.0 depending on the depth of focus i want
 
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