XF300 - very bad Moire pattern

[Martin Campbell]

Recently shot a corporate conference vid with my XF300, and the speaker was wearing a thin stripe shirt. At some wide shots it's not to bad, but closer shots the picture is hellish! The Moire pattern is just all over the place. I have experienced this with my SLR's from time to time, but this is possibly the worst case I've come across, and certainly didn't expect it with this camera.

I shot at full 1080 and 50i, and output Full res quicktime to put through compressor and create Standard DVD.

Can anyone advise what I can do about this in future? Can what I have shot be sorted?


Thanks

[Antony Michael Wilson]

Check:

Custom picture settings - Canon defaults are too sharp. Start with the BBC settings and then reduce detail even further - to at least -7.

Monitoring. Did you monitor a baseband signal on a proper 1080 display first. This is obviously what you need to do to judge your settings first and foremost at native 1080. Judging sharpness/aliasing on a computer monitor is not good enough. Then move onto:

Down-conversion method. Even with a full 1080 setting tweaked to reduce interline twitter (shimmering on high frequency detail on a 1080 display) many established down-conversion methods will be inadequate because the source picture is so sharp. You need software or hardware with a sophisticated down-conversion algorithm that you can tweak to avoid introducing aliasing on the down-convert. Using Compressor templates directly on source pictures shot on default camera settings will just introduce more aliasing and is a very, very bad method in general with footage that comes close to the res limits of 1080 cameras.

There are several threads on here about both setting up this camera to avoid interline twitter at acquisition and proper down-conversion methodology in general. I'd run a search on both.

In short, yes, you can set up this camera much better than default in order to avoid this issue; the default settings have sharpening up way too high and you'll also not get away with anything less than very careful down-conversion methods.

[Tim Bakland]

I was never satisfied with the down-conversion from HD to SD with this camera until I started tweaking the "frame controls" in compressor's quicktime settings, making sure motion estimation was set to "best." Moire pattern can still be a problem (esp. in SD down-convert) though, particularly with those sorts of details -- lines, bricks, etc.

[Martin Campbell]

Originally Posted by Antony Michael Wilson

Check:

Custom picture settings - Canon defaults are too sharp. Start with the BBC settings and then reduce detail even further - to at least -7.

Monitoring. Did you monitor a baseband signal on a proper 1080 display first. This is obviously what you need to do to judge your settings first and foremost at native 1080. Judging sharpness/aliasing on a computer monitor is not good enough. Then move onto:

Down-conversion method. Even with a full 1080 setting tweaked to reduce interline twitter (shimmering on high frequency detail on a 1080 display) many established down-conversion methods will be inadequate because the source picture is so sharp. You need software or hardware with a sophisticated down-conversion algorithm that you can tweak to avoid introducing aliasing on the down-convert. Using Compressor templates directly on source pictures shot on default camera settings will just introduce more aliasing and is a very, very bad method in general with footage that comes close to the res limits of 1080 cameras.

There are several threads on here about both setting up this camera to avoid interline twitter at acquisition and proper down-conversion methodology in general. I'd run a search on both.

In short, yes, you can set up this camera much better than default in order to avoid this issue; the default settings have sharpening up way too high and you'll also not get away with anything less than very careful down-conversion methods.

Thanks Antony. I've been hunting for the BBC settings you referred to, but cannot see them listed anywhere. Can anyone do me the enormous favour of posting a link to it? (could be a good idea for mods to post settings stuff like this as a header sticky?)
I monitored on a standard LCD screen, but output DVD to view on full res plasma.
I'm still very much getting used to this camera and the step up from my previous, but I have to say - I have still to find a colour setting that I can rely on throughout a day. Simply having something that gave me fairly vibrant colour with nice deep blacks would be great. So far some colour settings I've used have been alright for outside, and when moved indoors, people's faces look purple like oopah loompahs!
Another thing, whilst the LCD monitor is so pin sharp, my picture output appears to be a lot lighter when input into edit that it showed on camera LCD - I'm having to really keep an eye on this now.

Originally Posted by Tim Bakland

I was never satisfied with the down-conversion from HD to SD with this camera until I started tweaking the "frame controls" in compressor's quicktime settings, making sure motion estimation was set to "best." Moire pattern can still be a problem (esp. in SD down-convert) though, particularly with those sorts of details -- lines, bricks, etc.

Thanks Tim, yes, - It appears I will have to try a different workflow of outputting to FCP from now on.

[Mikko Topponen]

Your output to dvd was probably screwed. Like if you just put the HD version onto DVD Studio Pro it will convert to SD with very, very bad quality. This will introduce all kinds off artifacts.

There are lots of ways to screw up the scaling. Check your programs and settings.

[Martin Campbell]

i usually take my ProRes version and run it through compressor DVD best quality 90min setting, and then take it into DVD Studio Pro. Will need to look into what I have to do now in that process.

[Mark R. Olsen]

Originally Posted by Martin Campbell

Thanks Antony. I've been hunting for the BBC settings you referred to, but cannot see them listed anywhere. Can anyone do me the enormous favour of posting a link to it? (could be a good idea for mods to post settings stuff like this as a header sticky?)

Here is a link to the BBC, A Roberts report.


http://cpn.canon-europe.com/files/ne...305_report.pdf

[Antony Michael Wilson]

It is also important to point out that Alan's [BBC] settings are just a starting point. Alan generally measures cameras' performance on static test charts for specific purposes. If you stick to the the Alan Roberts/BBC settings, you'll find that you'll still have aliasing on brickwork/roof tiles and eye glasses on moving images. If you further reduce mater detail to around -7 this problem will start to go away.

As to the down-conversion methodology, you just have to experiment with the tools you have and/or can afford. Turning on the frame controls in Compressor and setting everything to 'best' will improve things [assuming you start with an image that isn't aliasing at native res] but will not be ideal. There are much better and faster tools for high quality down-conversion than Compressor. Ignore the mpeg2 encode for DVD for a bit and experiment with down-conversion as a separate step using different software or - better still - dedicated hardware options. It will be worth it because you absolutely can produce good smooth/sharp SD pictures for DVD or SD master tape from the XF.

[Mikko Topponen]

FCP7 is also pretty weird in the way it downscales.

My workflow is to do a quicktime conversion export from the HD timeline (progressive sequence) to an SD prores at 720x576 (pal). This prores will be taken to dvd studio pro and it will not scale it again.

Though if I export using the "quicktime movie" export setting as SD then it will have bad scaling artifacts. It just seems that FCP7 has a lot of weird quirks.

You need to watch the actual image at 100% with a progressive monitor before coming to conclusions about moire. A lot of TV inputs actually treat the image interlaced and do a quick bob-deinterlace thereby increasing the "aliasing".

[Bill Weaver]

Any thoughts on 720?

Yes, the XF is sharp, even at -10 setting, which can cause some problems down line.

Because of that, and because I find that sharpness a bit distracting for storytelling, I've been thinking a lot about going to 720p30, as it softens the look a bit.

Opinions? Better to soften in post and start with highest rez?