Originally Posted by ScottAvery
I am looking for a dedicated 3d projector to complement my JVC rs540...
I have a JVC RS520 and had a similar quest. I wanted an ultra short throw or very short throw projector that I could sit on a stand beneath and close to the screen as I did not want to ceiling mount a projector. I ended up getting a Benq. I looked at the HT2150ST but ended up with a TH671ST. It was a fair bit brighter in 3D mode than the 2150ST and I am not bothered by rainbow effect. Here is my comparison between it and my JVC.
First - I only consider using the Benq for 3D. 2D performance is not a contest with the JVC the clear winner.
My JVC has 1400 hours on the bulb. I have a 118" 16:9 screen (1.0 gain). I have the JVC behind the back wall (no noise - nice) but the longer throw of 18' 4" does lose some lumens due to its zoom position. I measured its best 3D mode (high lamp with a custom calibration for 3D) with my pseudo test pattern. I just used Chapter 3 of the first Lichtmond 3D Blu-ray where it fades to full white to get the projector in 3D Mode for this measurement. I don't really know for sure that this is a proper full white image but I used the same image for both projectors so it is a direct comparison.
The Benq is located at its optimal brightness location and I also have it set with a slightly lower gamma since I use it just for 3D (2.0 vs 2.2 for the JVC).
Both projectors lose a staggering amount of light output in 3D mode and more with the shutter glasses.
These measurements were with both projectors displaying a 3D "white" full screen image (see above).
JVC measured 150 Lux (with 1400 hours bulb wear and non optimal placement).
Benq TH671ST measured 250 Lux (with new bulb and optimal placement).
(for comparison the Benq HT2150ST I also evaluated with new bulb measured 195 Lux in this test).
JVC colors looked undersaturated probably because of the lower lumens.
Benq colors looked very good if a bit over saturated. A surprise.
JVC has slight cross talk on some material. Can be mostly dialed out with the expense of brightness but in rare material is still shows.
Benq no cross talk that I observed. DLP a clear winner for this. This is the main reason I wanted to try a DLP.
JVC seems a bit better with Motion (I don't use its CMD however).
JVC also wins this but the overall effect is diminished by the dimmer image from the JVC (and the shutter glasses). I employed some family members to help me and both preferred the benq image for low light scenes. If I could have equalized the brightness this JVC advantage might be considerable. However, in my setup the Benq looks better mostly because it is just brighter (with new bulb and better placement).
The JVC operates at 96 Hz I believe in 3D (48 Hz per eye). The Benq 144 Hz (72 Hz per eye?).
There is a slight and subtle flicker to the JVC in 3D mode that is not present with the Benq. I notice it but many others might not.
In my setup with my JVC location and aged bulb the Benq is a clear improvement for 3D.
I only wish I could find an even brighter 3D DLP that would work in my setup.
For comparison I also have a 2016 LG Oled that is my gold standard for 3D. The Benq is the closest I have seen a projector get to its image. In fact if I reduce the screen size to 104" diagonal It is close to the experience I get with the LG. I can do that in my setup but I just prefer the larger image I get full frame on my 16:9 screen. Time will tell as the Benq bulb ages if this remains true.