<![CDATA[stair stepping / Alaising-Effect on 4K videoinput]]>Hello All,


I have a 4K input (from panasonic lumix gh4) on a PCI decklink mini Recorder 4k / Win 10, i7, Quattro M4000, Isadora 3.8 there is a very visible stair stepping / Aliasing Effect on all the lines/boarder of the objects (even with full frame antialiasing on in the preference video tab) -  as i want to capture a live drawing of an artist (and zooming in to the 4k quality) it is really a problem (alls the line of the drawing are stairs) if I switch to 1080p the problem is gone - anyone an idea how to fix this? 

best Bodo

]]>https://community.troikatronix.com/topic/7437/stair-stepping-alaising-effect-on-4k-videoinputRSS for NodeWed, 09 Sep 2026 00:19:06 GMTFri, 25 Jun 2021 15:24:57 GMT60<![CDATA[Reply to stair stepping / Alaising-Effect on 4K videoinput on Thu, 08 Jul 2021 21:05:21 GMT]]>@m_theater thanx for reply - I will check this when I`am back in the studio we have a 4k Monitor there...

]]>https://community.troikatronix.com/post/46387https://community.troikatronix.com/post/46387Thu, 08 Jul 2021 21:05:21 GMT<![CDATA[Reply to stair stepping / Alaising-Effect on 4K videoinput on Thu, 08 Jul 2021 21:00:14 GMT]]>@dillthekraut - it is set to HD - should be 4k?

]]>https://community.troikatronix.com/post/46386https://community.troikatronix.com/post/46386Thu, 08 Jul 2021 21:00:14 GMT<![CDATA[Reply to stair stepping / Alaising-Effect on 4K videoinput on Thu, 08 Jul 2021 12:06:51 GMT]]>@bodo

did you check your default resolution settings in preferences?

]]>https://community.troikatronix.com/post/46384https://community.troikatronix.com/post/46384Thu, 08 Jul 2021 12:06:51 GMT<![CDATA[Reply to stair stepping / Alaising-Effect on 4K videoinput on Thu, 08 Jul 2021 09:02:29 GMT]]>@bodo

i think that the internal scaling isn't working for you.

could you make a screenshot of the actual stage in 1920x1080, the floating preview window is not a good reference.

I think it would be worth to check how your 4k footage is presented on a a 4 screen, if you have non around you could emulate one with your quadro.

and check the difference in the screenshots.

from my point of view: if izzy is working correctly there shall be no influence apart from the yuv -> rgb transformation in the picture if you have a 4k camera / 4k processing / 4k screen.

if that is working correctly, perhaps you need a custom shader for a proper scaling

best clemens

]]>https://community.troikatronix.com/post/46383https://community.troikatronix.com/post/46383Thu, 08 Jul 2021 09:02:29 GMT<![CDATA[Reply to stair stepping / Alaising-Effect on 4K videoinput on Thu, 08 Jul 2021 06:16:32 GMT]]>@dusx 

hi dusx - I did a screenshot of the effect I mean and a recording with media express (which does not has this effect) - any idea why Isadora make this aliasing effect with the incoming stream and media express not?

thank Bodo

]]>https://community.troikatronix.com/post/46382https://community.troikatronix.com/post/46382Thu, 08 Jul 2021 06:16:32 GMT<![CDATA[Reply to stair stepping / Alaising-Effect on 4K videoinput on Fri, 02 Jul 2021 10:40:06 GMT]]>@fred and DusX - attached a screenshot 1. Isadora capture and 2. media express recording under same conditions - there is the aliasing effect with Isadora and not with media express???

]]>https://community.troikatronix.com/post/46362https://community.troikatronix.com/post/46362Fri, 02 Jul 2021 10:40:06 GMT<![CDATA[Reply to stair stepping / Alaising-Effect on 4K videoinput on Wed, 30 Jun 2021 05:45:12 GMT]]>@fred - Thank you very much I will try this!

]]>https://community.troikatronix.com/post/46356https://community.troikatronix.com/post/46356Wed, 30 Jun 2021 05:45:12 GMT<![CDATA[Reply to stair stepping / Alaising-Effect on 4K videoinput on Wed, 30 Jun 2021 01:47:50 GMT]]>Check you are actually getting proper 4k from your HDMI. The GH4 can output scaled resolutions over HDMI. Also check it with a 4k monitor to see if you have the same issues, also try make a recording with the blackmagic software and check to see if the recording has the same issues.

Try these instructions

https://www.lensrentals.com/pr...

]]>https://community.troikatronix.com/post/46353https://community.troikatronix.com/post/46353Wed, 30 Jun 2021 01:47:50 GMT<![CDATA[Reply to stair stepping / Alaising-Effect on 4K videoinput on Tue, 29 Jun 2021 15:28:35 GMT]]>@bodo

can you provide screen grabs to show what you are seeing?

]]>https://community.troikatronix.com/post/46352https://community.troikatronix.com/post/46352Tue, 29 Jun 2021 15:28:35 GMT<![CDATA[Reply to stair stepping / Alaising-Effect on 4K videoinput on Fri, 25 Jun 2021 15:41:50 GMT]]>actually if I zoom close and it is real in focus i see the stair stepping-effect even in 1080p....

]]>https://community.troikatronix.com/post/46341https://community.troikatronix.com/post/46341Fri, 25 Jun 2021 15:41:50 GMT