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Discussion Starter #1

i'm tempted to do the SF but don't know which one will be appropriate to my projector and with all the measurements and mixes are kind of confusing. before i get all the paints and other stuff i need some help of getting it right before i start or else i just spent amount of money that doesn't work. my projector is optoma hd25e and projecting 14 ft away from the wall about 120" diagonal. as far as ambient light its very little and usually will be watching movies during night time anyway. any suggestions or guidance will be much appreciated.
 

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DIY Granddad (w/help)
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Welcome to the DIY Screen Forum,

Silver Fire 2.5 4.0


In your instance, the 4.0 is not so much for ambient light needs as it is for improving Contrast and detail. And....you don't mention you adjacent room surfaces (side walls / ceiling) colors or their proximity to to screen, but the 4.0 will also serve you well in combating any reflected Projector-induced light.


Also, be aware of the Optoma's significant Image Offset (9")


When it's all said and done, you just might wind up enjoying how good the image will / does look in ambient light as well.
 

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Discussion Starter #3

thanks for reply mm. the walls are painted with flat mocha color and ceiling is also flat off white. is that going to affect the light of the projector to bounce off the screen from walls to ceiling?
 

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DIY Granddad (w/help)
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Quote:
Originally Posted by dvinez  /t/1523048/newbie-diy-silverfire-screen-need-help#post_24498082


thanks for reply mm. the walls are painted with flat mocha color and ceiling is also flat off white. is that going to affect the light of the projector to bounce off the screen from walls to ceiling?

It is all about proximity.


Mocha side walls won't hurt much at all if the screen's side edges are at least 3' to 4' away.


Ceilings are the worst offenders, being extremely large white expanses that tend to reflect and scatter light as they do. If the top edge of the screen is at or less than 12" away, then the Ceiling's influence will be extreme, necessitating that the area directly above the Screen be treated with, covered with, or painted with something to reduce reflections. When a Ceiling is White..and the screen is also White....even a distance of 24" can produce detrimental effects.


Can one get by without doing such? People have and do so all the time....until that one day comes when they really notice how much having the room light up of a sudden can affect the mood and presence a film can be trying to impart. Thing of it as someone got up and suddenly switched on a overhead light. After all, a large screen is nothing more really than itself a large source of reflected light, so if it's light is then also reflected off an adjoining surface, the amount of light within the room is increased proportionately.


However that is not the whole of it. The most essential aspect of having a dynamic, detailed image is the reproduction / retention of contrast...the difference between the darker and lighter elements of an image. That being so, a balance must be struck...or better still an advantage maintained by the projector vs the amount of light within the room. Light is the enemy of contrast....it washes out detail and turns black into gray.


A Projector with impressive contrast specifications that starts out with ultra deep black levels is a excellent start. One that has such AND also has a higher light output has a better chance of offsetting ambient light....but in the same respect can still deliver all that much more light to be reflected of a nearby surface.


A combination of a Gray screen surface that has gain, and a Projector that has both deep blacks and adequate lumen output can mitigate the effects of both ambient and reflected light. But only sensible degrees of such. Place a light source directly in front of or too the side of a screen, and it's almost always going to affect the screen's image to some degree. A White surface the worst. A Gray surface a bit less....a Gray surface with gain even less.


But if one can also dampen down the reflective tendencies of a closely adjoining surface, then that is a optimal solution. If the screen is not too awfully close, it need not be a case of turning that surface completely Black, just less reflective. But if the surface is at or less than 12" away....the darkest solutions, are the best solutions.


Some screen mfgs try to combat such issues by making a screen be overly retro reflective....that is to say they direct light almost directly back toward the source...not to the sides. Such "ultra high gain" screens can however come with decided caveats. They can reduce contrast....hot spot (noticeably brighter center).....have visible artifacts (sparklies and/or graininess) ...and cause eye strain (ie: staring at a too bright light...) Oh yeah....and they can cost a lot of money too.


All the latter being why we have for sometime now been focused on creating a viable DIY solution that can work at odds against all the detrimental aspects of light being present when a projected image is being viewed....be it directed light, ambient light, or reflected light. But sometimes a individual's own circumstances can make even that chore difficult. Someone who simply must have a "Floor to Ceiling" sized screen...another whose Ceiling is at or under 7'. And all too often it is a case where both circumstances involve White Ceilings.


Soooooooo..... somewhere along the line some degree of compromise must be struck. Usually, choosing the right Screen for a given projector /room combination is the best start. Then a practical placement of the screen. Intelligent lighting solutions and effective masking of windows are of course of paramount importance. And the....the room's own surfaces themselves. Balance them all into the equation and often none have to be done to the extreme.


It's up to the DIY'er to determine what they can, are willing to,or are allowed to do. We all on here can only educate and/ or advise.
 

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Discussion Starter #5

just measured the top edge of the screen its 8" away. i'm going to drop the top edge 2ft from the top of the ceiling and edge the screen i think it should be ok. as far as walls its about 7ft side to side. i'm going to get the materials this week and prep the wall today so i can start painting on weekend. thanks again!
 
 

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Discussion Starter #6

i'm getting a benq gp20 led projector has 700 lumens and 10k cr, just wondering if i should do the sf 1.0 or 2.0 since it has lower lumens?
 

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DIY Granddad (w/help)
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Quote:
Originally Posted by dvinez  /t/1523048/newbie-diy-silverfire-screen-need-help#post_24505114


i'm getting a benq gp20 led projector has 700 lumens and 10k cr, just wondering if i should do the sf 1.0 or 2.0 since it has lower lumens?


Ya thin so?


Man, I tell you the truth......


................you need RS-MaxxMudd LL using the newest Reflective components that are shared with the SF formula.


.............or more realistically.....choose another PJ, which I cannot advise you strongly enough to do so. I don't usually come down so strongly against anyone's PJ choices, but if 120"diagonal is in your mindset, there are other choices to choose from with better resolution, higher Lumens, better Contrast...and more features...and all are at about the same price point.


The whole truth? The BenQ GP20 simply cannot deliver the goods at 120" diagonal.
 

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Discussion Starter #8

well, i haven't order the benq yet i was just thinking might be good pj for my son's gaming since its led 20k hrs lamp life. but if its not bright enough for 120" i'll probably wait until next year for another model. i'll just stick with my optoma hd25e and get the screen going this weekend. thanks for advice mm. 
 
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