Best of luck,
No, just no :-) ... it will not be as good. You will also lose gain compared to what you have now. You have a good mid-end screen, and basically moving to a low end screen. There are some screen specific paints out there, not overly cheap. If you want to use standard paint, get pure white highly diffuse paint for the inside of signs. Does not screw up the color like most white paints.
I take it you like the size? I would be tempted for smaller and high end.
My first projector was originally used on the wall. It works just fine. Because of the way the eye perceives color, unless you choose some outlandish paint color it turns out the color of the wall beyond and around the screen area has a bigger effect on color accuracy than the color of the screen area itself.
Note for example the popularity of gray screens. I’ve seen side by side comparisons of different screens. A professional took swatches of different screen materials we literally set them up to view the same movie at the exact same time on multiple different fabrics.
Contrast is the single biggest factor in our perception of video quality. Because a projection screen is so large an area the screen itself becomes the largest light source in the room. Even a pitch black room is lit up real good watching a movie on a big screen. This light bounces around and right back onto the screen. A white screen reflects this ambient light much more so than a gray screen. I’ve seen it happen side by side. Done the comparisons. A gray screen is absolutely better contrast the vast majority of the time. In certain situations a white screen is only ever so slightly better, but only with something pure white on the screen. Even then you have to go back and forth looking real close to decide. The washout you get from ambient light in the room, this is no contest. The gray screen is much better. Think about how many times someone wants a little light to see their drink or food or whatever. Believe me, you want a gray screen.
Paint or fabric, the main difference is in terms of brightness. Some of the modern focused screens have gain and are very bright. However, because they are focused the extra brightness is only over a small area. Great if one or two people watching. The more and further apart the better a normal screen or painted wall will be.
Projecting on a painted wall is so easy. Simply point and focus. You will be shocked. You might worry that the texture applied on most walls would be a distraction. At the distance you sit, unless you have 50 year old popcorn texture, normal wall texture is completely invisible. Unless you have some bright color, just about any neutral egg shell sort of color, there isn’t even any need to repaint. Look at my room. https://systems.audiogon.com/systems/8367 Long before I bought the Stewart Filmscreen Grayhawk screen you see there today the gray wall was used. Almost never bothered to buy the screen, it was so good. In fact, the frame is the best part of the screen. If you hang a black frame on the wall it will be hard to tell you aren’t using a fabric screen!
But honestly, I only wrote all this to show off my encyclopedic knowledge. It really tweaks and triggers people, and I love doing that to certain ones here. Because seriously, I have to ask, why? You already have a very good screen. Is it to be able to project larger? That would make sense. Or are you having the viewing angle problem? The reason I ask is because unless you have some ulterior motive you’re not sharing (happens all the time) there really is no reason I can think of to be taking a step back.
Encyclopedic knowledge ... oooookay.
No, a painted wall and a screen are not the same thing. And YES, the color of the wall absolutely matters. It matters a lot.
Grey is not a color. It is white (reflective) with black (absorbs). However, many grey screens are much more than that. It will reproduce colors exactly like a white screen.
Painted walls do one thing. They reflect. You can choose diffuse in which case you will get good uniformity, and imperfections in the wall will be hidden. If you go more glossy, your light level increases, imperfections are visible, and uniformity drops. One good point miller makes it the impact of light from the screen hitting things and bouncing back on the screen reducing contrast. Diffuse paint sends light everywhere, so more chance of it happening, but, when the light does go back to the screen, it creates a diffuse reflection. With a more glossy paint, if the reflection is away from you great, if not, not so great.
Purchased screen material can not only have gain (and you can buy many different gains), unlike paint, high end screens can also reject ambient light. They have surface structures designed so that light that enters from a larger angle does not reflect forward. That matters even if your room is completely dark as the light from the screen goes out into the room and comes back has a lower chance of then being reflected at the viewer. The result is better contrast.
wrt white paint and off-white, etc. No, you need a perfectly white paint if you want the best quality (or perfectly grey). If you have an off-white paint, yes, your eyes will adjust to "white" when they are presented with enough white on the screen, however, the balance between the colors will all be off so colors will not look right. It is akin to looking at objects with a warm white, or bright white light. You will perceive white as white, but the colors will look much different under the different lights.
millercarbon7, I chuckled when I saw your system page, because I have a pair of Tektons on my radar screen. I'll probably go for the Ulfs if I ever pull the trigger.
The reason for considering a change is that I'm tired of a 16 ft screen dangling from the ceiling in my living room...and, I've secretly always wanted a 20 foot wide screen. There are no issues with the image with may current screen, it's just the placement of it I'm considering changing. Obviously I'm trying to do it on the cheap. I won't do it if the picture quality on the proposed painted screen is at least as good as my current screen. I refuse to sacrifice image quality.