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Putting a Polarization Filter on a too Bright Projector

2186 Views 19 Replies 8 Participants Last post by Scots, Aug 6, 2019

Grant Gabrielson

Discussion Starter · Aug 5, 2019

Hi everyone! First time posting on this forum, so please let me know if I'm in the wrong place.

I just bought an Optoma EH460 projector on eBay, it wasn't my first choice, but I wanted a current 1080P, 3d projector for under $300(I'm a nearly broke college kid) and this fit the bill. This projector retails for $1099 normally, but the guy I bought it from didn't know what it was and had it listed under the regulatory number instead of the model number.

This projector is 4800 lumens, probably closer to 3000 when in eco mode, but from what I've read, this will be too bright to get a good, contrasty image in a dark room(I plan to only have a 100" screen). So I'm thinking about putting a polarization filter 6 inches in front of the lens to cut down the brightness, is this a dumb idea? Should I just return or resell the projector? I plan to use it mostly for movies in a nearly pitch-black room and for parties with MusicBeam. Also, I saw that it has a 5 color wheel instead of the normal six, will this affect movies at all? It still has the normal 1.07 million colors.

Also, this is the EH460, not the EH460ST, and its from mid-2018 with what I'm told was sparse use, but I didn't get the actual lamp hours.
It won't let me post the link here because I'm new, but if you search eh460, you can find the spec sheet.
Thanks for your help!

1 - 20 of 20 Posts

DIY Guy

· #2 · Aug 5, 2019

Grant Gabrielson said:
Hi everyone! First time posting on this forum, so please let me know if I'm in the wrong place.

I just bought an Optoma EH460 projector on eBay, it wasn't my first choice, but I wanted a current 1080P, 3d projector for under $300(I'm a nearly broke college kid) and this fit the bill. This projector retails for $1099 normally, but the guy I bought it from didn't know what it was and had it listed under the regulatory number instead of the model number.

This projector is 4800 lumens, probably closer to 3000 when in eco mode, but from what I've read, this will be too bright to get a good, contrasty image in a dark room(I plan to only have a 100" screen). So I'm thinking about putting a polarization filter 6 inches in front of the lens to cut down the brightness, is this a dumb idea? Should I just return or resell the projector? I plan to use it mostly for movies in a nearly pitch-black room and for parties with MusicBeam. Also, I saw that it has a 5 color wheel instead of the normal six, will this affect movies at all? It still has the normal 1.07 million colors.

Also, this is the EH460, not the EH460ST, and its from mid-2018 with what I'm told was sparse use, but I didn't get the actual lamp hours.
It won't let me post the link here because I'm new, but if you search eh460, you can find the spec sheet.
Thanks for your help!

Grant,

Welcome to the forum. What screen material do you plan to use? Do you plan to calibrate the projector? These are variables that lower the light output.

If you use a grey material for your screen, you will perceive greater contrast from your projector. Calibrating for accurate color will also affect the lumen output of the projector. You should end up with a nice watchable picture that any starving student would be proud of.

I'm sure others will give you plenty of advice to get you where you want to be. Good luck on your new hobby.

Cheers,

Reactions: 1

Grant Gabrielson

Discussion Starter · #3 · Aug 5, 2019

DIY Guy said:
Grant,

Welcome to the forum. What screen material do you plan to use? Do you plan to calibrate the projector? These are variables that lower the light output.

If you use a grey material for your screen, you will perceive greater contrast from your projector. Calibrating for accurate color will also affect the lumen output of the projector. You should end up with a nice watchable picture that any starving student would be proud of.

I'm sure others will give you plenty of advice to get you where you want to be. Good luck on your new hobby.

Cheers,

Hi DIY Guy,
Thanks for the reply! I was thinking about justing using my wall, it's super smooth and white, but I think that might be too bright. I was thinking about using spandex because I've read it has a 0.7ish gain, but I'm afraid with this, some of the light will pass through, hit the wall and create a weird double reflection effect. Is this a valid concern? Is there any gray screen material you reccomend? I'm trying to stay under $75 for the screen if I can. For calibration, I think I am just going to use my phone camera sensor, I saw a guide on this and I think it will be fine, but the comments seemed mixed.
Thanks!
Thanks!

DIY Guy

· #4 · Aug 6, 2019 (Edited)

Grant Gabrielson said:
Hi DIY Guy,
Thanks for the reply! I was thinking about justing using my wall, it's super smooth and white, but I think that might be too bright. I was thinking about using spandex because I've read it has a 0.7ish gain, but I'm afraid with this, some of the light will pass through, hit the wall and create a weird double reflection effect. Is this a valid concern? Is there any gray screen material you reccomend? I'm trying to stay under $75 for the screen if I can. For calibration, I think I am just going to use my phone camera sensor, I saw a guide on this and I think it will be fine, but the comments seemed mixed.
Thanks!
Thanks!

Check out the DIY Screen forum and look into painting your wall with a grey screen recipe and if you want the defining edge, use a black border. Truly an inexpensive solution. Of course, be mindful of your Landlord / School dorm... ;-) As far as spandex, it's often used as an audio transparent solution if you're thinking of putting speaker behind the screen. There may be other inexpensive materials that would work for your situation if you check with the DIY screen group. Always compromises... just enjoy with whatever you decide to go with.

rekbones

· #5 · Aug 6, 2019

The EH460 is a strictly business class projector and definitely not ideal for dark room movies. Your idea of a ND filter is good to tame this down and lower the black floor but nothing will increase its contrast as it is what it is. Put the filter directly on the front of the lens no need to leave a space. The scenes where the projector will struggle is with dark low contrast images but bright punchy scenes like in sports it should work out well.

dreamer

· #6 · Aug 6, 2019

Grant Gabrielson said:
Hi DIY Guy,
Thanks for the reply! I was thinking about justing using my wall, it's super smooth and white, but I think that might be too bright. I was thinking about using spandex because I've read it has a 0.7ish gain, but I'm afraid with this, some of the light will pass through, hit the wall and create a weird double reflection effect. Is this a valid concern? Is there any gray screen material you reccomend? I'm trying to stay under $75 for the screen if I can. For calibration, I think I am just going to use my phone camera sensor, I saw a guide on this and I think it will be fine, but the comments seemed mixed.
Thanks!
Thanks!

Yes, even with a two layer spandex, you will get reflections from anything behind it. Usually the second layer is black spandex just to preserve the acoustic transparency and put speakers behind the screen. If you don't care about putting speakers behind the screen, just want the smoothness of spandex, you can put a more solid black fabric as backing for the white spandex face.

In answer to your original question, people have use "Neutral Density" filters from photography suppliers to cut the light output of projectors without messing up the color. This can be a better option than a gray screen if you like to watch 3D movies, because 3D needs all the brightness you can get.

Grant Gabrielson

Discussion Starter · #7 · Aug 6, 2019

DIY Guy said:
Check out the DIY Screen forum and look into painting your wall with a grey screen recipe and if you want the defining edge, use a black border. Truly an inexpensive solution. Of course, be mindful of your Landlord / School dorm... ;-) As far as spandex, it's often used as an audio transparent solution if you're thinking of putting speaker behind the screen. There may be other inexpensive materials that would work for your situation if you check with the DIY screen group. Always compromises... just enjoy with whatever you decide to go with.

I know I can't paint the walls, but I'll check out the DIY forums for some info on making a spandex screen.
Thanks!

Grant Gabrielson

Discussion Starter · #8 · Aug 6, 2019

rekbones said:
The EH460 is a strictly business class projector and definitely not ideal for dark room movies. Your idea of a ND filter is good to tame this down and lower the black floor but nothing will increase its contrast as it is what it is. Put the filter directly on the front of the lens no need to leave a space. The scenes where the projector will struggle is with dark low contrast images but bright punchy scenes like in sports it should work out well.

It was either the EH460 or a refurbished BenQ ht1070a, I decided on this one because the contrast for the 1070a was only 15000:1 and this one was listed as 20000:1, is there more to contrast ratio than just the published number and lumens? It also had a better brightness uniformity, 75% vs 60%. There was a used EH460ST that sold on eBay for like $700, i think I might be able to get $600 for the normal EH460, and have about $500 leftover after ebay fees and shipping costs. Would I be better off buying another $500 projector?
Thanks so much for your help!

Grant Gabrielson

Discussion Starter · #9 · Aug 6, 2019

dreamer said:
Yes, even with a two layer spandex, you will get reflections from anything behind it. Usually the second layer is black spandex just to preserve the acoustic transparency and put speakers behind the screen. If you don't care about putting speakers behind the screen, just want the smoothness of spandex, you can put a more solid black fabric as backing for the white spandex face.

In answer to your original question, people have use "Neutral Density" filters from photography suppliers to cut the light output of projectors without messing up the color. This can be a better option than a gray screen if you like to watch 3D movies, because 3D needs all the brightness you can get.

With a polarization filter, do you think this would produce a better picture than the budget Benq Ht1070a or other similar projectors?
Thanks for the help!

dreamer

· #10 · Aug 6, 2019

Grant Gabrielson said:
With a polarization filter, do you think this would produce a better picture than the budget Benq Ht1070a or other similar projectors?
Thanks for the help!

I don't know if a polarization filter is the same thing -- never heard anyone use one of those.

No 5-segment color wheel projector is going to produce as accurate color as a RGBRGB color wheel. No RGBRGB projector is going to be as bright as a 5-segment with the same power lamp. If 3D doesn't interest you, then an RGBRGB projector with a light grey screen would a better choice.

rekbones

· #11 · Aug 6, 2019

Grant Gabrielson said:
It was either the EH460 or a refurbished BenQ ht1070a, I decided on this one because the contrast for the 1070a was only 15000:1 and this one was listed as 20000:1, is there more to contrast ratio than just the published number and lumens? It also had a better brightness uniformity, 75% vs 60%. There was a used EH460ST that sold on eBay for like $700, i think I might be able to get $600 for the normal EH460, and have about $500 leftover after ebay fees and shipping costs. Would I be better off buying another $500 projector?
Thanks so much for your help!

Manufacture published specs especially contrast is just marketing BS and no where near the real world. I doubt anyone in the Home theater realm has even tested a EH460 so I have no clue as to the real #'s as business class projectors are designed for being optimized for presentation displays. Generally in these projectors contrast and color accuracy is sacrificed for over all brightness. I not saying these can't be used for HT but usually they don't preform as well as a projector designed for HT like the 1070a.

bud16415

· #12 · Aug 6, 2019

https://www.viewsonic.com/us/pro7827hd-s.html

Reactions: 1

noob00224

· #13 · Aug 6, 2019 (Edited)

bud16415 said:
https://www.viewsonic.com/us/pro7827hd-s.html

Great price and superior to the HT1070a.

This type of projector (RGBRGB color wheel) is better in almost every way than the Optoma EH460. It's plenty bright, great with 3D. For lights on viewing the difference will not reflect the lumen difference since light will wash out the image of the Optoma as well. Strategically placed lights (not pointed at the screen) will work well with the Viewsonic.

DIY Guy

· #14 · Aug 6, 2019 (Edited)

Grant Gabrielson said:
I know I can't paint the walls, but I'll check out the DIY forums for some info on making a spandex screen.
Thanks!

Grant,

Here's a couple of other options for screen material. https://www.carlofet.com/projector-screen-material/flexigray-projector-screen-raw-material.html

https://www.amazon.com/s?k=projector+screen+100+inch&i=electronics&crid=30832IYVLN029&sprefix=Projector+Screen%2Celectronics%2C196&ref=nb_sb_ss_i_7_16

bud16415

· #15 · Aug 6, 2019

noob00224 said:
Great price and superior to the HT1070a.

This type of projector (RGBRGB color wheel) is better in almost every way than the Optoma EH460. It's plenty bright, great with 3D. For lights on viewing the difference will not reflect the lumen difference since light will wash out the image of the Optoma as well. Strategically placed lights (not pointed at the screen) will work well with the Viewsonic.

I wouldn’t say it was superior but it is pretty close. It has some nice features including the RGBRGB dark chip 3 1080p system. It is higher lag and a little louder than the HT2050A but 240 less if you can live with a refurbished unit. Much safer bet than a used projector IMO.

noob00224

· #16 · Aug 6, 2019

bud16415 said:
I wouldn’t say it was superior but it is pretty close. It has some nice features including the RGBRGB dark chip 3 1080p system. It is higher lag and a little louder than the HT2050A but 240 less if you can live with a refurbished unit. Much safer bet than a used projector IMO.

I think he was referring to the 1070a. Has a smaller chassis and around 33ms lag. The viewsonic is 50ms I believe.

Dave in Green

· #17 · Aug 6, 2019

Grant Gabrielson said:
It was either the EH460 or a refurbished BenQ ht1070a, I decided on this one because the contrast for the 1070a was only 15000:1 and this one was listed as 20000:1, is there more to contrast ratio than just the published number and lumens? It also had a better brightness uniformity, 75% vs 60%. There was a used EH460ST that sold on eBay for like $700, i think I might be able to get $600 for the normal EH460, and have about $500 leftover after ebay fees and shipping costs. Would I be better off buying another $500 projector?
Thanks so much for your help!

You are making the classic projector newbie mistake of choosing on exaggerated manufacturer specs rather than on trusted professional reviews. The BenQ HT1070A would be a much better all-around projector for your needs. Just read the following pro review. You won't find any review of the EH460 that rates it higher than the HT1070A for primarily viewing movies in a dark room. The ViewSonic Pro7827HD-S would be at least comparable to the HT1070A.

hometheaterhifi.com/reviews/video-display/projectors/benq-ht1070a-3d-dlp-projector-review/

bud16415

· #18 · Aug 6, 2019

noob00224 said:
I think he was referring to the 1070a. Has a smaller chassis and around 33ms lag. The viewsonic is 50ms I believe.

I saw that. I don’t think the ht1070a is available any longer and if you did find one new stock they have them priced as high as the ht2050a. The ht2050a solved a lot of the problems and is now a very mature product that would do an excellent job for anyone wanting an entry level 1080p HT projector. It is out of the OPs price range.

The refurb ht2050a is now 559 and the pro7827hd-s is 375. that’s 184 difference. The ht1070a refurb was selling for 299 and that was a great deal for a RGBRGB 1080p projector.

Dave in Green

· #19 · Aug 6, 2019

bud16415 said:
I saw that. I don’t think the ht1070a is available any longer and if you did find one new stock they have them priced as high as the ht2050a. The ht2050a solved a lot of the problems and is now a very mature product that would do an excellent job for anyone wanting an entry level 1080p HT projector. It is out of the OPs price range.

The refurb ht2050a is now 559 and the pro7827hd-s is 375. that’s 184 difference. The ht1070a refurb was selling for 299 and that was a great deal for a RGBRGB 1080p projector.

The OP thought he had found a refurbished HT1070A. But it's possible that most HT1070A refurbs were sold out a long time ago and you can't get one directly from BenQ. It's possible that any remaining units might be rejects with performance issues. On the other hand ViewSonic is selling Pro7827HD refurbs direct at a lower price that comparable performing models from BenQ and others. So it may be the best refurb available right now in that price/performance range. Projectorcentral.com sure liked it a lot when they reviewed it:

projectorcentral.com/viewsonic-pro7827hd-projector-review.htm

Reactions: 1

Scots

· #20 · Aug 6, 2019

I remember reading up on Mississippi man posting a link to this for a screen backing somewhere in the diy section. Anyways HD can cut it down to the size you need, use the more experienced members paint recommendations and suspending it from the wall or if your not allowed to drill into the wall build a cheap frame out of 2*3 to attach/suspend it from. I can't see this totaling more than $75

Also sorry turns out my post count is not high enough to post links yet but search up Eucatile Hard board thrift white. It would allow for a 100" screen or install a layer of black felt around the edge of the border to stop any bleeding and causing more reflections.

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