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Kona 3 10bit Downconvert is SOFT

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Matt Wilson
Kona 3 10bit Downconvert is SOFT
on Nov 17, 2008 at 10:00:49 pm

We have a longstanding project that requires we shoot in HD but deliver in SD.

We have been shooting 3-camera DVCPRO HD (on the Pani HDX900), and bringing footage into FCP via BVW-500 deck and Kona 3 card at 10bit anamorphic doing SD downconvert on the way in. We then cut in a multi-clip anamorphic sequence, laying off to Digibeta using Kona’s SD-to-SD letterbox setting.

We had done a number of tests to see which workflow worked best (HD 16:9 in with SD letterbox out; SD letterbox in/out; etc), and that's how we came up with the Anamorphic flow (though if I recall, they all basically looked the same).

Problem is, it’s always seemed soft to our eye — especially on our JVC LCD monitor (which is blowing up the image).

So we did a test, having the source footage downconverted out of house via a traditional Teranex-based setup — 16:9 DVCPRO HD to 4:3 Letterboxed SD DigiBeta.

We brought that footage in at 10bit SD and it looks FAR superior to the Kona’s results.

So the question is: Are we fools for buying the Kona 3, expecting that it would deliver on its promise of “Broadcast-Quality Conversion” or are we just doing something horribly wrong?

Any insight, much appreciated.



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Matt Wilson
Re: Kona 3 10bit Downconvert is SOFT
on Nov 17, 2008 at 11:41:30 pm

The system specs are

MacPro 8-Core 2.8Ghz
CalDigit HD One 4TB External RAID
Kona 3
FCP Studio 2
JVC DT-V24L1DU Monitor



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Carsten Orlt
Re: Kona 3 10bit Downconvert is SOFT
on Nov 18, 2008 at 5:53:03 am

typical 'Bang for bugs' problem.
Aja does a good but not 'great' job on down (or up) conversion.
The term 'Broadcast quality' is unfortunately a term that is not defined by how it looks but I guess about if the tech specs are met, e.g. colour space conversion, luminance levels, blanking etc.
So the much more specialized and more expensive Terranex will do a better job, but you have to pay for it. If your budget doesn't allow for that, then the Kona quality is what you have to live with.
One thing I noticed is that Color does actually a better downconvert then the ioHD which I have (and according to Aja is based on the same hardware downconverter as the Kona). Export you FCP HD seq to Color and change the project setting to SD and adjust the picture via the Geometry room. Needs a lot of rendering, but this is back to the bang for bugs problem.

You should though look at the converted image on a SD CRT monitor to make the final judgment as the JVC introduces another scaling step and this might effect the end result. I doubt though that the result will be much different as you said the Terranex looks better even on the JVC. But maybe the Kona conversion will look acceptable on the SD CRT (if you can't spend the money on the Terranex conversion).

but maybe somebody else has another opinion on this?

Cheers Carsten

Carsten


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gary adcock
Re: Kona 3 10bit Downconvert is SOFT
on Nov 18, 2008 at 7:10:24 am

[Matt Wilson] "Problem is, it’s always seemed soft to our eye — especially on our JVC LCD monitor (which is blowing up the image). "

Matt - what part of that is good? Carsten is right you need to judge your content correctly and up scaled god knows how on an LCD is not a good start.


"So we did a test, having the source footage downconverted out of house via a traditional Teranex-based setup — 16:9 DVCPRO HD to 4:3 Letterboxed SD DigiBeta.
We brought that footage in at 10bit SD and it looks FAR superior to the Kona’s results. "


Depending on which Terenex model used you may have had a +$100K piece of dedicated hardware handling the processing with noise reduction and additional image processing - and comparing that to a $3k capture and playback card.
- Not really a fair comparison even for a zoomed in image on an LCD, do you think?

That same kind of AJA hardware is the basis of Avid's Nitris or Autodesk's Smoke, Flame, Lustre product lines but as Carsten adds there is no spec for "broadcast quality".

Yet that same AJA conversion is used by literally 100's of stations and facilities everyday for exactly the same thing you are doing without the as much as 15 frame delay of the processed image on the dedicated hardware. ( AJA has a 1 frame delay on all image conversions)

I have never ever said that the conversion was as good or better than the dedicated hardware like a Teranex / Ukon / Alchemist conversion.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

Inside look at the IoHD
http://library.creativecow.net/articles/adcock_gary/AJAIOHD.php




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Jeremy Garchow
Re: Kona 3 10bit Downconvert is SOFT
on Nov 18, 2008 at 12:17:56 pm

Also, doing the SD to Sd conversion is not really the best kind of conversion on the Kona card. That feature was added to appease user requests. If you want the best conversion from your Kona, I'd edit in HD and then use the letterbox down convert.

If you are still unhappy, you can then use a teranex. As Gary said, depending on the version of Teranex, that thing has a processor per pixel. Think about that for a second. For every pixel in your image, the Teranex has a processor to follow it along in it's little conversion journey.


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Dan APPEL
Re: Kona 3 10bit Downconvert is SOFT
on Nov 18, 2008 at 2:51:24 pm

Anyone have any experience with the TERANEX MINI?

It's much less elaborate -- it only does HD/SD size (not rate) conversions -- but apparently uses the same algorithms (?) as its $25-35K siblings, but costs only $2,500. Sounds sorta good to be true, but according to Teranex, they get the same call that Matt complains about on a weekly basis.

And when I called AJA about the same problem (softness on the HD to SD downconvert) the other day, the technician's ultimate response was, "Well, I guess it sorta is what it is..."






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Joey Burnham
Re: Kona 3 10bit Downconvert is SOFT
on Nov 18, 2008 at 10:02:04 pm

Agree with everyone above. I just noticed that doing downcoversions on layback is superior to downconverting on ingest. Kinda lame considering when I don't ship out for a downconversion (usually do) have to go from deck to NLE back to deck then back to NLE...




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Dan APPEL
Re: Kona 3 10bit Downconvert is SOFT
on Dec 7, 2008 at 3:02:35 am

For what it's worth, we demo'd the Teranex Mini and it WAY outperforms the downconvert (HD-SD) from the Kona 3. It has no bells or whistles -- it just does size conversions -- but the results were far sharper than that of the Kona. Sorta bummed that I seemingly wasted the extra money on the Kona 3 (as opposed to the LH that I had originally intended to purchase), but what are you gonna do? Live and learn: Ca-ching.






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gary adcock
Re: Kona 3 10bit Downconvert is SOFT
on Dec 7, 2008 at 3:29:18 pm

[Dan APPEL] "the Teranex Mini and it WAY outperforms the downconvert (HD-SD) from the Kona 3. It has no bells or whistles -- it just does size conversions -- but the results were far sharper than that of the Kona. Sorta bummed that I seemingly wasted the extra money on the Kona 3 "


Hoes that teranex mini capture or do dual link? No
Does it handle 23.98? No

How much does it cost and what else does it do?

Of course a dedicated piece of hardware, one that only does one thing-frame conversion, will do better that a device that is not dedicated to a single task.

Just don't shoot 23.98 and expect it to work in E to E






gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

Inside look at the IoHD
http://library.creativecow.net/articles/adcock_gary/AJAIOHD.php




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Dan APPEL
Re: Kona 3 10bit Downconvert is SOFT
on Dec 7, 2008 at 4:07:06 pm

All I'm saying is that I wish the Kona 3 did a better job at HD/SD conversion. Yes, it does A LOT -- and I do appreciate it, even if my previous post belies that fact -- but conversions are integral to what we do -- and seemingly integral to what Aja is selling in this product.

Perhaps Aja might want to reconsider (or redefine) billing the Kona 3 as "broadcast quality" when the visual results of the conversion -- what we see on the screen (which is the most important aspect) -- is so poor.



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gary adcock
Re: Kona 3 10bit Downconvert is SOFT
on Dec 7, 2008 at 5:04:47 pm

[Dan APPEL] "and I do appreciate it, even if my previous post belies that fact -- but conversions are integral to what we do -- and seemingly integral to what Aja is selling in this product. "

I went back and re read you post and it sounds as if you were better off with something else.

I am not going to dispute that teranex does better conversion, but when it is all that the mini can do for that same $3000 off course it damn well should be better at it. A dedicated stand-alone piece of hardware will always do a better job at something that is a multi-tasker.

That being said AJA's downconvert is not any different that you would have on a Sony Deck lets say, and it is also the same standard that Avid uses on Nitris and Autodesk uses on Flame, Inferno and Lustre. I use it all the time - most often in side by side HD and SD comparisons on set and no one has ever said to me that it was not an acceptable output. Not once.




gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

Inside look at the IoHD
http://library.creativecow.net/articles/adcock_gary/AJAIOHD.php




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