How'd your silver fire screen turn out?
Also something to note about gain is when it goes up, aside from a reduced viewing cone, typically black level performance goes down and white level performance goes up.12 foot-Lamberts is considered the minimum screen brightness for a completely light controlled room. Many people may disagree with that, and some have far less than that and find it acceptable, but that is the recommended min. The SMPTE and THX standard is 16 foot-Lamberts, and movie theaters usually produce between 12 to 22 fL of light at the screen. Television produces 35 fL or more depending if it's standard definition TV or HDTV.
So if you are less than 12 fL at the screen, that means you either should think about
For those that already purchased a projector, option 1 on the list is out of the question. That leaves a smaller screen or higher gain.
- A brighter projector
- A smaller screen
- Higher gain
Gain is tricky. Some people guess at gain based on comparisons to other materials. This could be dead on accurate, but it certainly isn't reliable. Even commercial companies are sometimes guilty of using testing methods that do not adhere to industry standards and as such they may list 'custom' gains that are unrealistic. One company lists a gain of 1.8 for their CRT White, however when it was formally tested and reviewed, it was not as bright as a StudioTek 130 which has a gain of 1.3. The estimated gain was placed at 1.0 when the company stated it was 1.8.
Gain can bring the fL up to the level needed for a good sharp and vivid image, but many times people get caught up in the numbers. Higher gain is not always better. When gain goes up, the viewing cone goes down. Viewing Cone is the angle at which the screen brightness drops off dramatically from the on axis image. This cannot be avoided, as gain goes up viewing cone goes down, period.
Gain is a measurement of the reflectivity of any screen or projection surface. The gain number represents a ratio of the light that is reflected from the screen as compared to the light reflected from a magnesium oxide reference source. So a screen rated with a gain of 1.0 will reflect the same amount of light as a magnesium oxide reference, and a screen rated at a gain of 1.5 will reflect 50% more than the reference source. This does not mean light is being produced. There can never be more light than what the projector itself creates, and from the instant it leaves the bulb, the energy starts to decrease.
How this works is a 1.0 gain screen is referred to as a unity gain screen. This type of screen has an even amount of light dispersion across the entire surface of the screen and will look just as bright off axis as on axis. Once the gain increases, the light has to come from somewhere and in essence it comes from the off angle reflected light. Since more light is being focused and returned to the on axis viewing position, the off axis angles become dimmer. For the most part this is not a big issue since people normally do not sit at that far of an angle to a screen, but in certain venues such as a church, auditorium, or a bar, there usually are extreme viewing angles present. The angle at which the gain reading drops to 50% of the peak value is known as the Half Gain Viewing Angle. A person viewing the screen from this angle will see an image half as bright as the person seated at the center position.
A high gain screen does not typically reflect red, green, and blue equally. This can produce color shifts in the image that are very noticeable when the screen is viewed from different angles.
Ideally for Home Theater use, the gain is normally between 1.0 to 1.8. That isn't a set rule though and some may prefer a brighter image, but the brighter the image is, the more eye fatigue that occurs. There will be a point that even a two hour movie can induce a headache from strained eyes caused by a screen being too bright.
No doubt (in hindsight). I just never expected the wall texture to be an issue since I had never seen it shooting to my basic beige wall or even after rolling two coats of primer. i now realize that any high contrast paint is going to accentuate texture, blemishes, etc. Lesson learned.Sounds like you may have wanted to paint a substrate then, huh? Major bummer! Let us know what we can do to help!
Go with the Winter Mist. True Value - $9 - one quart. You leave now you may be watching tonight! Get the latex flat obviously! :bigsmile:With the size screen I am shooting for (120-126") the choice of substrates seemed pretty slim. Now I need to look in to that again and see what might work. For obvious reasons I find myself again wondering about a 122" DW or FG. :wits-end: