Aliasing

[Windjammer]

Good point

[10s]

Nice work Barry, ... once again!

[adkimery]

Very interesting article Barry (as usual). Just goes to show that, again, there's no such thing as a free lunch.


-Andrew

[Cranky]

That's what I would consider the ideal. But not 2mp, you'd want at least 3mp. You have to factor in the resolution loss due to the Bayer pattern and demosaic process, so you need about 3 megapixels to deliver a truly sharp 1080p image.

Incedentally, this is what the HMC40\TM300 has, 3MP per chip. But these are three-chip cams, do they use Bayer pattern? Do they NEED to be 3MP each?

[Barry_Green]

A three-chip camera would not use a Bayer pattern. The Bayer pattern is necessary because CCD and CMOS chips are monochrome; therefore to get a single chip to see in color you need a Bayer pattern. Three-chip systems don't need or use the Bayer, they use a prism to split the light and direct the red, green, and blue to individual chips.

Those cams probably have denser chips to improve the still-camera functionality...

[ravencr]

Can I reduce the sharpening in the scene file section of my HMC40 to reduce this from happening?

Chris

[Seamus McFlannel]

Barry,
This is a great article. I have a question in this regard that concerns the Scarlet, or rather the speculative information that has been disseminated about it. It seems that they are calling it a DSMC, and they are saying it is both a motion picture and a still camera. So, would the same problems apply in this case. It does seem that is primarily a motion camera though. The reason I'm asking is that I have almost made the decision to buy an HPX300 along with the P+S Mini35C. But then I started reading about the Scarlet S35. From what I've been reading, it looks as though the cost of the Scarlet with the necessary features would cost about the same as the HPX300 with the P+S Mini35C. So I'm wondering if I should wait for the Scarlet as it will take the same lenses I would use for the Mini35 but be less cumbersome and it would have a much larger imager. The rolling shutter would not be an issue as both the HPX300 and the Scarlet both use CMOS chips. BUT, if the the Scarlet would have aliasing issues, I wouldn't be interested.
With all that said, and with what we currently know, which do you think would be a better buy for the money.
By the way, I am strictly a cinema style shooter.
Thanks again for the article.
Seamus

[adkimery]

W/regards to Red, the Red One has been used for high-end still photography (for example Megan Fox's spread in Esquire) so whatever balancing act they've come up seems to be working (or at least 'good enough').


-A

[strangways]

W/regards to Red, the Red One has been used for high-end still photography (for example Megan Fox's spread in Esquire) so whatever balancing act they've come up seems to be working (or at least 'good enough').

The thing with HDSLRs is, as Barry says, "You can't have a single system designed to render 21-megapixel stills, and 2-megapixel video, simultaneously"

The RED ONE is (various cropping choices notwithstanding) a 12-megapixel sensor, doing 12-megapixel stills, and 12-megapixel video, simultaneously. Hence, no aliasing problems because the OLPF is designed for 12-megapixels, and that's all it ever records.

Of course, to be able to record 12-megapixel video, they are recording at a data rate that is 10 times higher than the HDSLRs!

[Al MacLeod]

Writing this article on aliasing must have taken some time!
After reading it I don't think rolling shutter meets the test for aliasing. The depiction of the propeller blades a cmos sensor renders is accurate. It just represents motion differently than a global shutter would. There is no extraneous or additional information added, nor is any information deleted.
I guess it's a definition thing.