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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 :)

2K Soft Focus on all Red Ones

ronx said:
Yes, that does make sense. the olpf is never going to be 100% efficient, and a 2k olpf design would make for soft 4k footy.. but when blown up to 2k, might not be strong enough..
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The OLPF has nothing to do with 2k or 4k. It's strength is chosen solely based on the size of the pixel plus amount of anti aliasing desired and not the total resolution. It cares not about 2k or 4k.
 
personally I've had trouble getting 2k and 4k to match perfectly, even when downrezzed to HD but I wrote it off as the 2k crop showing the limitations of my lenses. Hearing mitch say that red 2k is "a bit soft and flarey" relieves me a bit cause I thought I was either doing something wrong or crazy. Both may still be possible.
 
I'm not sure what to make of this thread... I haven't shot much 2K since Build 16, so maybe something has changed. But I have done a bunch of testing in the past, 2K vs 3K vs 4K. And I see no discernible difference between the three formats when shot with the same lens and viewed at 1:1 pixels with the same debayer settings.

All RED footage is a bit soft and flarey... The soft is partially due to the OLPF and also because the camera provides no sharpening or other internal processing -- that is to be added in post.

And Carsten is correct, the OLPF is not designed for 4K or 2K or whatever. It is tuned to the size of the pixels or photosites on the sensor. The OLPF and photosites operate no differently when you shoot 2K than when you shoot 4K and simply crop out the center.

Anyway, now I'm inspired to do some testing... My camera is out on a job, but I'll have to shoot some tests in a day or two when it's back.

Most every complaint I've ever encountered in regards to 2K vs. 4K is comparing final output or transcode resolution. If you take 2K and output to 1080p and then take a 4K frame and do the same, of course the 4K is going to look a hell of a lot sharper and more detailed. But if you shoot the same subject with the same lens and same camera settings, but one shot at 2K and another at 4K and then crop both to the same frame size, you should get the same image, or at least close enough that only your compositor might be able to tell the difference after analyzing wavelet variants.

If comparing a full debayer and 1:1 pixels of a 2K frame and a 4K frame are giving noticeably different results, then there is something wrong with the camera firmware or in the post or image-viewing process.
 
Keep in mind that a 2k image is 1/4 the spatial resolution of the 4k image for the same field of view.
 
Jeff Kilgroe said:
Most every complaint I've ever encountered in regards to 2K vs. 4K is comparing final output or transcode resolution. If you take 2K and output to 1080p and then take a 4K frame and do the same, of course the 4K is going to look a hell of a lot sharper and more detailed.
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Yeah, but if you shoot RED at 2K alongside a good 1080P camera like the Sony EX1 the 1080P looks better in rough tests I've done. I never really understood that... but I wonder if it has to do with the debayering. Isn't 4K RED really 3.2k or so? Perhaps a 2K RED shot really feels lower rez in the same way?
 
Joel Kaye said:
Yeah, but if you shoot RED at 2K alongside a good 1080P camera like the Sony EX1 the 1080P looks better in rough tests I've done. I never really understood that... but I wonder if it has to do with the debayering. Isn't 4K RED really 3.2k or so? Perhaps a 2K RED shot really feels lower rez in the same way?
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The EX1 is sharpened but at the same time it doesn't have full 1920x1080 resolution either. Full resolution would be quite aliasy. It's important to have more pixels in your format than you have resolution/detail because you need to resolve the transitions between details smoothly. Take out those transitions and you're left with a harsh, albeit high resolution image.
 
Carsten Fenstermacher said:
The EX1 is sharpened but at the same time it doesn't have full 1920x1080 resolution either. Full resolution would be quite aliasy.
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Not exactly true. The EX1 has full raster 1920x1080 chips. There is a prism which ostensibly functions as the OLPF but that is not the same as the Bayer-patterning that he was referring to when he mentioned 3.2K for RED's 4K (which I do not completely agree with anyway). If you want to go by that standard, NO sensor has full resolution, so it becomes a specious argument.

This is when I get to the point of nothing that specs are just a bunch of numbers and pixel count is not at all an accurate way to measure resolution. All that matters is MTF. This is the functional resolution, the resolving capabilities of the system. It can be determined using several systems, including measuring off an IMATEST chart. It is very possible to have a 1080 camera out-resolve a 2K camera, or even a 4K camera for that matter.
 
My main problem is when shooting plates for compositing in 4K and need an off speed version at 2K, the 2K version is so soft that it's impossible to pull a matte.
If the objects of interest are anywhere from 15 feet on they're basically out of the window of usability for whatever reason (MTF, OLPF, WTF etc.)

When shooting high speed 2k you'll end up compensating exposure by opening up more and using a wider lens to match the 4K FOV, by the time you get to focus in on your subject at 15' the focus marks seem to be closer to infinity and the picture is totally soft and unusable.

I wasted a lot of shots before I gave up on shooting VFX with the Red, I admit they had to pry it from my fingers but I just had to let it go.

It's my hopes that this thread helps other VFX teams from thinking that they've done something wrong and wasted as much time and money as I have renting new lenses and wasting more shots.

I also hope that there might be a software firmware something that might solve this issue or at least make sure it doesn't become adopted into future Red Cameras.
 
keicol said:
I also hope that there might be a software firmware something that might solve this issue or at least make sure it doesn't become adopted into future Red Cameras.
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5k at 100fps in epic should be pretty obvious it's a solution already announced, no?
 
What if you wanted to go faster and use a lower res? Will this problem be back to haunt us? It's better that we address this now, no?
 
Now we're entering into oxymoron territory.
faster frame rates at lower resolutions is...
still lower resolution.

So you want higher resolution and faster framerates but then want even faster framerates at lower resolution but still higher resolution?
 
Ariana,

Thanks for your comments. Let's try and keep this on target. The Red One has serious problems with a soft picture at 2k off speeds rendering it useless at wider shots with subjects at around 15'. If we can possible get Red to address this and or save others from wasting time and money trying to figure this out then that's a good thing.

If you have anything to contribute please do.

Thanks, Keith
 
keicol said:
Ariana,

Thanks for your comments. Let's try and keep this on target. The Red One has serious problems with a soft picture at 2k off speeds rendering it useless at wider shots with subjects at around 15'. If we can possible get Red to address this and or save others from wasting time and money trying to figure this out then that's a good thing.

If you have anything to contribute please do.

Thanks, Keith
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Useless? Tell that to my clients who've I've shot multiple projects with lots 2k at 120fps and loved the results.

Maybe you should try and grasp that shooting a lower resolution image at 1/4 the size of 4k means you'll be getting lower resolution before you start proclaiming that the sky is falling.
 
The best way to shoot high speed when shooting RED is to bring in a Phantom HD. Seriously, I bet a very large percentage of our Phantom rentals is as a B camera to a RED shoot. They play very well together. The 2K coming out of the Phantom HD is crystal clear.
 
When expecting better results shooting digitally for VFX shots and then discovering that to get the intended results that you have to revert back to film then to me, 2K becomes useless. When I'm working on a 200 million dollar project that demands perfection and the VFX supervisor tells me that the Red can't deliver a workable 2K off speed shot and reverts back to film, well, let's help others from falling into that position.
I'm glad your clients are happy with your work.
Cheers!
 
Mitch Gross said:
The best way to shoot high speed when shooting RED is to bring in a Phantom HD. Seriously, I bet a very large percentage of our Phantom rentals is as a B camera to a RED shoot. They play very well together. The 2K coming out of the Phantom HD is crystal clear.
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I found the Phantom to be on the harsher side for image quality an aliasing. Can you say why it's using a mild low pass filter?
 
Carsten, I believe you used the camera before it had an OLPF in it.
 
Guys,

The Phantom is an obvious solution but unless you own one it becomes another rental.

The point is that we have a great 4K camera, why can't it shoot 2K with the expected drop in resolution and the expected effects from going to a wider lens and maybe a bit more open iris but still give us a usable picture with subjects at about 15'?

Why should we have to resort to film, the Phantom, or the SI2K, even the F900 has a better look?

Somethings wrong that might be an easy fix, maybe? Software, firmware, it's not the lens, it's using the center of the chip, it sounds perfect, so why the problems?

Can it be fixed? Can we hope that future versions of the Reds will be able to jockey about the resolutions and frame rates and still be able to intercut no matter what the shot without having to rent other manufacturers' products?
 
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