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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Half Res. Good vs. Full Res. Premium

I must say that I find the right image the technically "best" in all ways, even containing significantly more detail and info, and thus - to me - it appears sharper, although I understand what you're saying.

Initially - when I first got my RED - I used to finnish off a grading session with some mild sharpening.
Rarely happens these days.

I have shot quite a few rez-tests on RED - which is pretty scientific, and I am in no doubt that the full debayers do the best job from a purely technical point of view. The reason the RED feels soft compared to say a few of the 1080 cams out there, is that they actually give us a wee bit less than 1080, and thus appear more attenuated/sharper, and being used to that - the RED may look "softer".

That doesn't really mean that it is, though.

That said. I am NOT into discussing aestethic preferences. those are subjective and should remain so. I respect yours, and rthey interest me. I look a lot more into what happens to gradients, shadows and skintones than to apparent sharpness (no offence intended with the wording here, just didn't know how else to put it...)

One thing, I'd like to see you try, though, was to do a full debayer, and THEN add some sharpening and compare THAT image with the half debayer.

My hunch is that the latter approach would give you the sharper image, but with the gradients and skintones intact...

But as I said: This is just a hunch...
 
Check these out:

Andrae Palmer said:
http://farm6.static.flickr.com/5059/5435306014_1df70d3cc6_o.png (Full Res Premium - Radius Sharpening 40% in Davinci Resolve)

http://farm5.static.flickr.com/4104/5435304602_e6a4629172_o.png (Half Res Good - Radius Sharpening 40% in Davinci Resolve)

http://farm6.static.flickr.com/5293/5434692043_b6eeb19d1e_o.png (Half Res Good - No Sharpening in Davinci Resolve)

In my opinion if you are going out to a 2K or 1080p timeline... 1/2 Res Good debayer is where it's at.
Click to expand...
 
Andrae,

Personally, I like Full Res Premium the most. But Half Res Premium does look very good too.

I'm not sure if the extra detail you're seeing is real detail or guessed at detail added by a little bit of computer algorithm magic.

But IMHO, go with what you like. It really comes down to taste. And I can certainly see why you like the "Half Res Premium."

BTW, thanks for posting the sharpened images. They looked really brittle. Good to know.
 
Ciao Andrae,
have to experiment with different resolution 3 frame , without and with 100% sharpnes with Davinci REsolve , sharpnes is add with final cut.
I agree with Moretti and Groven, I prefer full but you have to say that even half the quality is very nice.
Andrae in this test the perception of brightness is ok at Full to 1/2 to 1/4.
you remeber your post this:
Notice the loss of detail in the headboard texture and how it affects perception of brightness... same goes for the eyes.

http://rapidshare.com/files/447786729/luigi.mov
http://rapidshare.com/files/447787784/luigi_sharpen.mov

ciao
thanks
Luigi
 
The half res shots sharpened look much coarser to me. Not pleasing. The full res premium keeps the detail but with a much finer texture.
 
Will rendering in full help reduce the apparent noisines of an image? After all I am rendering to full 4k and then downrezing to HD. Seems to make all our secondaries and keys less noisy.

Is this just "perceptual" from my end ;-)
 
luigivaltulini said:
Ciao Andrae,
have to experiment with different resolution 3 frame , without and with 100% sharpnes with Davinci REsolve , sharpnes is add with final cut.
I agree with Moretti and Groven, I prefer full but you have to say that even half the quality is very nice.
Andrae in this test the perception of brightness is ok at Full to 1/2 to 1/4.
you remeber your post this:
Notice the loss of detail in the headboard texture and how it affects perception of brightness... same goes for the eyes.

http://rapidshare.com/files/447786729/luigi.mov
http://rapidshare.com/files/447787784/luigi_sharpen.mov

ciao
thanks
Luigi
Click to expand...

Luigi thanks for posting your clips. I see more shadows in the eyes at a 1/4 Res on the clips you posted especially when compared to 1/2 Res (luigi_sharpen.mov). The sharpening you added was way too much.... doesn't look like it was the same amount on all three clips. The 1/2 res looking worse than both the full and 1/4 (noise wise).

5443092489_40fed20126_o.png


A lot more brightness in the eyes (especially left), blouse and foliage in the background:
5443693994_c519567e4e_o.png
 
Frank Cueto said:
Will rendering in full help reduce the apparent noisines of an image? After all I am rendering to full 4k and then downrezing to HD. Seems to make all our secondaries and keys less noisy.
Click to expand...

That's true for two reasons:
– any serious downsampling (other than just dropping pixels) involves some interpolation and consequently reduces noise on the pixel level
– full debayer generates less noise, try something very low-light and compare

BTW, noise can produce apparent sharpness, just like aliasing (think 5D/7D).
 
Andrae Palmer said:
Luigi thanks for posting your clips. I see more shadows in the eyes at a 1/4 Res on the clips you posted especially when compared to 1/2 Res (luigi_sharpen.mov). The sharpening you added was way too much.... doesn't look like it was the same amount on all three clips. The 1/2 res looking worse than both the full and 1/4 (noise wise).

5443092489_40fed20126_o.png


A lot more brightness in the eyes (especially left), blouse and foliage in the background:
5443693994_c519567e4e_o.png
Click to expand...


Ciao Andrae,
I added some noise to the maximum to see the difference, I believe that the brightness' in this case is due to the peaking of the detail, what do you think Andrae?
Have you tried 7.1.1 I'm still out here, you have found differences in performance?

ciao
Luigi
 
luigivaltulini said:
I believe that the brightness' in this case is due to the peaking of the detail, what do you think Andrae?
Click to expand...

Yes I believe it's due to the peaking of the detail... if you look at most clips with the actors eyes you will see loss at a 1/4 Res and blurriness at full debayer. There is just not much sparkle there... 1/2 Res. Good looking the best in my opinion. Now full debayer may have more resolution... but we perceive sharpness easier and expect it in a good image.

I haven't tried 7.1.1 as of yet... still on 7.1. Will give it a try soon.
 
No... but I did try full debayer and 40. Posted the results in this thread.


Andrae Palmer said:
http://farm6.static.flickr.com/5059/5435306014_1df70d3cc6_o.png (Full Res Premium - Radius Sharpening 40% in Davinci Resolve)

http://farm5.static.flickr.com/4104/5435304602_e6a4629172_o.png (Half Res Good - Radius Sharpening 40% in Davinci Resolve)

http://farm6.static.flickr.com/5293/5434692043_b6eeb19d1e_o.png (Half Res Good - No Sharpening in Davinci Resolve)

In my opinion if you are going out to a 2K or 1080p timeline... 1/2 Res Good debayer is where it's at.
Click to expand...
 
How about posting a full res premium debayer without sharpening? Those other examples are so sharpened that they look unnatural.
 
Sidney L. Plaut said:
ill try and ask about downsample algorithms/ filters again.

When using the RED rocket which always does a full debayer, which downsample algorithm does it use? (mitchel, CatMul, Gauss...etc)

and why would you chose a LESS sharp algorithm?
Click to expand...
Graeme, I'd be really curious about that too.
When using Red Rocket, can you choose which downsample algorithm is being used ? If not, which one is used by the card by default ?
And also, what is your advice on which one we should use if going from 4K to 1080p ? Does that change if we started with some 4K-HD footage ?

Regarding the discussion, I find the Full debayer much more pleasing, even if it feels a little bit softer indeed. The noise characteristics especially in the darker areas are much nicer than with the 1/2 debayer.
Also, I think that to really be able to judge, you have to see it moving, the perception is probably very different from just looking at a still image.
 
Vision & Physics

Vision & Physics

Sharpening (like unsharp mask), actual resolved line pairs, acutance, microcontrast and contrast range all have a potentially powerful impact on each viewers perception of sharpness. For more detailed info I recommend the investigations of Mark Shubin.

Beyond the image metrics mentioned above, there are a host of issues related to the human visual system and the particular display/viewing environment that can skew perception. For example the eCinemas look great in a dark room but flat and soft in moderate to high ambient light. Taste and creative intent is a whole other thing on top of that.

It is my contention that 99% of the displays out there in 2011 are poor performers for high resolution with subtle detail reproduction. Most are 8 bit with dithering for starters. Moreover, I believe the insane amount of sharpening common in broadcast HD and the overly punchy default settings on most displays has "conditioned" our perceptual evaluation markedly.

In a perfect world all distribution would be ACES compliant masters with output LUTs matched to the display device with an ambient light level correction curve, but I'm not holding my breath.

Cheers - #19
 
I hate to sound like a jerk here, but if you properly focus your images with good lenses, full debayer looks plenty sharp - no cheap and tacky sharpening tricks needed.
 
Qualifies for "Longest Time Between Post and Reply" Feb - Nov
 
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