Sefton Bates : 2 hours ago
Via email, Philips confirmed that they use a 0.23 DLP chip. This would be the Texas Instruments DLP230NP. In the datasheet, TI state it “displays 1920x1080 pixels on the screen” but they do not ever refer to this as “native resolution”. A bit more digging shows that this has a 960x540 DMD array that uses actuation to give an apparent 1920x1080 image. But, at any one point in time, only 960x540 pixels are being displayed on the screen. So calling this a “native 1080p” projector is misleading.
Is it true and native 1080p is marketing bullshit only?
See now you’ve made me go down the rabbit hole on DLP and DMDs to see how all this works. But if the DMD you linked is the one being used in the PPM, then every aspect of the TI marketing says it produces a 1080P image.
It produces a 1080p image, but it uses pixel shifting to achieve that. So it is not native 1080p, but you will get a 1080p image which should look the same as a native 1080p image.
Guyyyyyyyssss, please… Are we still talking about this?
Yes its a real 1080p. Some others brand says 1080p supported, means you can input 1080p but the image projected is WVGA or 720p…
But in our case, you input 1080p, and you get 1080p in your wall/screen
Agreed.
People get confused with the fake “full hd” low cost projectors whereby they only support 1080 but show lower resolutions.
In the case of the ppmax, it’s all about the work “Native”. Yes people will see natively lines of 1080 pixels, generated from a lower number of mirrors thanks to the speed of the shift.
No the DMD is not native 1080 pixels because the DMD is made of mirrors, not pixels ! and it has a number of mirrors which differs to the number of pixels on screen. Result is pretty much the same (whith caveat of super fast moving images where the speed of the shift might impact image smoothness).
Hmmmm…if this is official Philips, and bit unprofessional response. A lot of us are new to the PPM parade. I’m just curious how it works, if the actual mirror array on the DMD is actually “half” the total count required for HD. I’m reading up on TRP pixel architecture where they claim this works, but since most of the documentation out there is about the standard DMD, which is “simply” on off switch for light for each pixel, I don’t get what they’ve done to double the rez count. I see TRP adds “roll on and roll off”. I know this forum isn’t a technical forum, so I’m just curious. It’s incredible tech that we can get a full HD image from a .23 inch DMD at well north of 200 lumens. Clearly this latest pico chip is the foundation of Philips choice to build this projector here and now.
Just to be clear, this isn’t Philips technology. It comes straight from Texas Instruments. The entire array is mounted on a quadrature voice coil and shifted half a pixel in each direction while it draws 4x the frame rate. That, plus some image processing.
Maybe because of pixel shifting to get 1080p and moves to merge RGB colors we have a shatter effect that written about in Image quality subjective review.
Where the pixel shift might be objectionable is very very fast action, such as sword play scenes or when punches are being thrown very near to the camera. In this case it appears the PPM GPU can’t keep up and drops the highly changing frames, and the pixel shift drawing style exacerbates the issue.
For me it is all somewhere between truths. Because I’ll have 1080p on a wall, but with some kind of shortcomings or crutches which I can’t see in first use (or in a store for preview when it will available), but I’ll recognize during usage of PPM.
I’ve read that, but I’d like to know the conditions of that test. For instance I’d be trying to playback the scene with an external HDMI device so we can rule out the PPM GPU.
Good question. I’ll try to do a 4 way test between raspberry pi 4 to PPM over HDMI, Android to PPM over USB C, playing locally on a microsd stick in the PPM, DLNA streaming, all using the same time and see if I can see any difference.
Hi guys, it’s a very relevant topic and worthy of clearer explanation.
1080p via pixel shifting is every bit as native as almost all consumer 4K projectors. You get a 60hz refresh rate and 1920x1080 pixels on the wall.
If you don’t interpret it as 1080p, remember that other display technologies like wheel-based projectors (lamp light instead of led light) also use similar tricks: a lamp based projector has a rotating wheel which alternately shows red green and blue channels of the image. Some also have yellow or white. So you never really see the entire rgb pixel at once. In fact even on non-pixel shifting dlp the same principle applies, the mirrors alternately show each separate colour channel one after the other.
The speed of this switching is fast enough that you typically won’t notice a different even at 60hz and surely not at 24hz. But this is a bit subjective, some people are more sensitive to this, just like the “rainbow effect” on wheel based projectors.
We don’t believe that this qualifies as false marketing. On the other hand, there are many advantages to using this newer DMD than the bigger 1080p option without pixel shifting. It uses substantially less power which makes it possible to make the PicoPix Max so portable, and for the battery to last up to 3 hours long. Where it makes sense to use the larger 1080p DMDs, we’ve done so, for example on the Screeneo S and U series projectors.
Regarding all the questions/remarks regarding to the DLP + Actuator/pixel shifting polemic… Does anyone know if the 30 000hours lifetime advertised is for the LED+actuator (so the mechanic part is included in the advertised lifetime), or if the lifetime actually is only for the LED but not for the actuator/mechanical part?
For me this is the only point which matter actually! Don’t want to be screwed with a 30 000hours LED still working but a broken actuator (and so a bricked projector!)
