Pixellation in 50P/60P mode

[Chris Harding]

Hi Guys

I know Pete Rush was having some issues in 50P with pixellation especially on cheek bones of people (because it tends to be a high lighted area). Peter also had a few issues with areas that are slightly over-lit or over exposed where the colour goes either weird or smudgy. Did you sort them out Pete?


Has anyone else had these kind of issues lately.

Chris

[Chris Harding]

I did a few tests today as the morning was nice and sunny both in HA mode (17mbps) and PS Mode (28mbps) to see if I could pick up any posterisation or pixellation on objects and faces and nothing showed up at all. However I WAS using the no profile setting instead of my usual PP3 so I'm wondering if the fact that PP3 pushes detail in shadows means that it might also push details in overexposed highlights too?? I tried over exposing a face (reluctant wife) and the cheek bones are clean even if they are bright.

Pete? What was the outcome of your white toaster in the driveway test ?? The only other variable was that I was using my 28-75 and 17-50 Tamrons as opposed to the stock lens but I cannot see how the lens would contribute to the issue

Anyone else see the problem on 50P footage ..my 50i and 50P footage are virtually identical ..very hard to tell apart with a variety of objects/scenes/people so I'm really not sure what causes the issue.

Chris

[Peter Rush]

Hi Chris - I'm right in the thick of it at the moment so don't have a ton of time but I can definitely tell you that using PP3 as soon as skin tones over expose I get posterization - not nice at all, and not the graduated blow out that even though incorrect at least looked nicer on my old Z1. It seems to affect skin tones more than say white shirts/dresses etc

The last few weddings were on really sunny days so I'm constantly concious of blowing out any highlights so I'm watching my Zebras like a hawk - resulting in somewhat underexposed shots to keep the wedding dress from blowing out etc, but they can easily be fixed. I haven't had time to do a 50p vs 50i yet.

Manual knee settings on my white toaster test tended to flatten the gradation - auto yielded a more natural blow out.

[Noa Put]

If I recall right I had the best results using no preset at all, pp3 was useful inside though as it didn't crush the blacks that much but no preset gave me the nicest image overall but that can be up to personal taste. I"m sure 50p/50i has not much to do with it, those presets mess with the image the most and can have side effects.

[Chris Harding]

After tests today Noa I think you are right on the button. In 50P I could not detect any evidence of any of Pete's issues using no profile on the camera .. I must admit I never used Panny's scene files when I had my HMC cameras either. I am pretty sure that PP3 is the problem ... You can easily use it indoors as well but it does over saturate facial tones but that's easy to do by just dropping saturation level a small amount.

Funny I have never had the issue using 50i and using PP3 but then I have to put up with a tiny resolution drop and I do tend to get worse moire ..(well not really moire but like shimmering on something like brick paving) which doesn't happen in 50P

I do realise you are busy Pete as it's your peak season and it's our dead period due to the cold and wet weather in Winter here. Maybe you need to just turn off profiles ... the result is very consistent ...I'm not sure what "no profile" has applied but I know on my Panasonics, no scene file (or using their default Scene 1) they had everything set to default which was usually zero and they worked pretty well ...It's much easier to do a tiny saturation adjustment than try to "repair" posterisation problems.

Thanks again guys!!

Chris

[Peter Rush]

I did a wedding fairly recently with no PP and it really does crush the blacks which then need lifting - maybe it's just my preference :/

[Chris Harding]

Thanks Pete

Yep is does make black very crushed and sadly most weddings are snow white dresses and jet black suits so we have to contend with a huge contrast ratio. I also find that indoor footage with no profile needs a touch of de-saturation as skin tones tend to make people look a little over tanned!! That also seems to fix the blacks to a degree too!! However it seems to fix the posterisation issue though which is good.

In Sony Vegas Colour Curves I have a preset curve I made up that lifts detail in shadow areas and also kills the black level a bit which works very well with indoor footage ... Are you happy with colour saturation otherwise? It was hard with my test yesterday as it wasn't a very bright day. Dave Vickers used the "no profile" on his Golf Video and it looked pretty good to me. I think by controlling the black/white blowouts and using this preset we will not get any posterisation at all.

Chris

[Chris Harding]

Hi Pete

I have just finished shooting a fun run this morning and checked the footage all shot in PSMode and there is no funny pixellation nor any weird colour even on blown out faces (it was an early one ! Yes I had to get out of bed at 4am and it was 5 degrees outside!) so as the sun came up during the race I had a few blown out faces but none of the issues you seem to have so it maybe looks like the trouble-maker is definitely the PP3 setting??

Just thought I would let you know

Chris

[Peter Rush]

Thanks Chris - For now I'm going with PP3 for indoor work (ceremonies/speeches etc) and no profile for outdoor filming. When this season dies down I'll be doing some tests ready for next season.

[Chris Harding]

Great Pete

When you get a chance Adobe must have some sort of colour curves and if you use a stock standard diagonal curve and just add a small bump in the bottom bit it kills any over crushing of blacks and also brings the skins tones back to normal using no profile. I was going to stick with PP3 indoors but I KNOW I will forget to change the darn profile ..I have done it before so I'll just add the curve in post. That way I don't have to remember to change it.

The thing that worries me is the time factor at a Church ..the bride walks out of the entrance after doing her exit and sometime during the time she leaves the interior and hits the sunshine you have to stop the camera and change the profile and maybe miss things that are going on.

I only have one wedding this month being freezing July so I'll just shoot with none ..My wedding next weekend is an outdoor one too!! Crazy bride !!

I'll let you know what I find with changing the black level in post for this one.

I must admit the fun run this morning looked rather good but I still had to tweak the saturation up just a tiny bit to make it perfect...it really works well in bright daylight! I had one staff member on the run actually looking straight into the sun (for some warmth I suppose) and her face blew out totally but still quite usable with nothing weird.

Chris

[Peter Rush]

Here's another example - The marquee was quite dark so I let the outside over expose - look at the bridesmaid's face! This was using PP3

[Chris Harding]

Hey Pete

I looked thru all my corporate footage from Sunday and there was plenty of faces from the fast changing light and not a single issue with the no profile so it must be the PP3 setting that doesn't like bright conditions in any part of the frame. Mine was all in PS mode too ! I did another shoot today with a talking head and again clean as a whistle so I really think that it's the profile that's causing the issue as it's designed to lift detail out of shadows and when it gets an over-exposed shot it also lifts the detail and causes the posterisation issue. Part of my shoot today was also indoors and yes, the blacks are crushed but I'd rather drop their level than have to contend with the weird colours. The no profile also pushes the range quick hard and I find that sometimes blacks seem to drop below zero and whites go over limit on my vectorscope waveform so I have a colour curve corrector have kills the top and bottom levels to keep them in limits and the pull the black level just a wee bit.

I think it's definitely the PP3 lifting the shadow detail too much. I'm shooting everything with no profile now. The curve is really simple ..it kills blacks below the 16 level and kills whites higher than 234 ...without the curve blacks go all the waway to zero and whites to 255

Chris

[Peter Rush]

+1 Chris - I'm going to continue using PP3 for indoor work but will use no profile for outdoors - a bit of tweaking in post and it's good to go - think I'll keep the EA50 for next season as well - loving it with my Canon lenses!

Pete

[Serggio Lamas]

i have Pixellation and blur video in Night Scene low light,with the stock lens,I do not have another lens 2.8 to compare.The Pixellation comes from the lens or the sensor camera?
50p not test in 50i

[Noa Put]

Originally Posted by Peter Rush

Here's another example - The marquee was quite dark so I let the outside over expose - look at the bridesmaid's face! This was using PP3

I didn't see that example before, it must have something to do with how the camera processes overexposed areas, I have not seen this kind of behaviour yet on my 1080p 50p camera's.