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AnalogRocks Forum Moderator
Joined: 08 Mar 2006 Posts: 26690 Location: Toronto, Ontario, Canada
TV/Projector: Sony 1252Q, AMPRO 4000G
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gjaky
Joined: 05 Jun 2010 Posts: 2790 Location: Budapest, Hungary
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AnalogRocks Forum Moderator
Joined: 08 Mar 2006 Posts: 26690 Location: Toronto, Ontario, Canada
TV/Projector: Sony 1252Q, AMPRO 4000G
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Link Posted: Sun Jun 21, 2020 2:26 pm Post subject: |
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gjaky wrote: | Pure sh!t |
Why so?? This style of DIY is how I stumbled on this website in 2005 or so. I was getting the stuff together to build a DIY projector, back then you would have used a 15" or 17" LCD panel, or one of the low res SONY PS1 LCD folding screens.
Then I stumbled on the fact CRT projectors were coming up surplus, so I bought one at the local pawn shop. My first SONY 1252.
There was a local guy that had a lightening strike take out his 58" RPTV. He did this style projector using a 17" LCD and a video scaler to drive it. Built it inside the old TV case.
Now, what was the name of that forum? DIY projector...something
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gjaky
Joined: 05 Jun 2010 Posts: 2790 Location: Budapest, Hungary
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Link Posted: Sun Jun 21, 2020 2:55 pm Post subject: |
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The problem is not with the DIY attitude, but with the claims he mades.
He entertains the idea that if you put some random stuff together you'll get a useful projector out of it. I don't want to discredit his efforts but the thing is not as simple as he shows, and is even harder to reproduce.
Start with the obvious:
- How would you manage color balance with a "random" white LED? Does that phone let's you calibrate colours accurately?
- What about contrast ratio? I don't think this projector would have any better contrast than any LCD projector from 20 years ago...
- I understand that the phone could stream any movie over Wi-Fi (in order to avoid the pain to copy the movie on the phone), but will you use a 3.5mm jack and a Dolby Pro Logic receiver to get surround sound?
So yeah, it's great to have a super duper DIY 4K projector with low light output, bad contrast ratio and colour space that surely won't even meet Rec.709. While all hot (4K) movies are processed in HDR and at least DCI-P3.
And apart from watching movies what else exactly can you do on this projector? -Is there any port on Android for space invaders?
_________________ projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
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garyfritz
Joined: 08 Apr 2006 Posts: 12026 Location: Fort Collins, CO
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km987654
Joined: 25 Jul 2007 Posts: 2857 Location: Australia
TV/Projector: Barco BG809s
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Link Posted: Mon Jun 22, 2020 9:01 am Post subject: |
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Looks great. I am sure its not perfect but I don't believe he thinks that either. If he didn't use the mirror and turned the PJ on its side it would be brighter as mirrors are not 100% efficient although he would need another lens wouldn't he?
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kal Forum Administrator
Joined: 06 Mar 2006 Posts: 17860 Location: Ottawa, Canada
TV/Projector: JVC DLA-NZ7
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Link Posted: Mon Jun 22, 2020 1:41 pm Post subject: |
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I'd like to see someone who actually knows something about projectors, calibration, and how to measure the results do something like this.
Would be useful if some actual numbers on the performance of the DIY unit were provided instead of hyping that it's 4K (as if that matters if the rest is crap). All he says is useless things like "the contrast is great" and that "video playback is fantastic" and then shows screenshots of the two saying "see how much better it looks?" which makes absolutely no sense. You can't gauge anything through a video taken off some camera displayed on your own display.
Nothing wrong with DIY, juts call it for what it is. It would actually be a fun build.
Kal
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kal Forum Administrator
Joined: 06 Mar 2006 Posts: 17860 Location: Ottawa, Canada
TV/Projector: JVC DLA-NZ7
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Link Posted: Mon Jun 22, 2020 1:52 pm Post subject: |
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gjaky wrote: | - I understand that the phone could stream any movie over Wi-Fi (in order to avoid the pain to copy the movie on the phone), but will you use a 3.5mm jack and a Dolby Pro Logic receiver to get surround sound? |
He actually mentions at one point in the video that that is exactly what he does (well, uses headphone out to power external speakers). Probably $5 powered computer speakers. That would be in line with the image quality you get out of the projector.
Kal
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AnalogRocks Forum Moderator
Joined: 08 Mar 2006 Posts: 26690 Location: Toronto, Ontario, Canada
TV/Projector: Sony 1252Q, AMPRO 4000G
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Link Posted: Mon Jun 22, 2020 2:35 pm Post subject: |
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kal wrote: | I'd like to see someone who actually knows something about projectors, calibration, and how to measure the results do something like this.
Would be useful if some actual numbers on the performance of the DIY unit were provided instead of hyping that it's 4K (as if that matters if the rest is crap). All he says is useless things like "the contrast is great" and that "video playback is fantastic" and then shows screenshots of the two saying "see how much better it looks?" which makes absolutely no sense. You can't gauge anything through a video taken off some camera displayed on your own display.
Nothing wrong with DIY, juts call it for what it is. It would actually be a fun build.
Kal |
Now you've got the picture
It's a fun build that does something when you're done. It doesn't have to be perfect it just has to be.
As for sound, yeah, no losless Dolby or DTS but think of a teen/20 somethin building this for $250 ish bucks and how cool they would be. Although getting an HDMI signal in there is an issue so no PS4 or Xbox but there's always android gaming. Not everyone cares about perfect color space nor calibration.
I know when I stopped watchin test patterns and started watching TV and Movies I was much more entertained
_________________ Tech support for nothing
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HD done right!
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AnalogRocks Forum Moderator
Joined: 08 Mar 2006 Posts: 26690 Location: Toronto, Ontario, Canada
TV/Projector: Sony 1252Q, AMPRO 4000G
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Link Posted: Tue Jun 23, 2020 2:14 am Post subject: |
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km987654 wrote: | Looks great. I am sure its not perfect but I don't believe he thinks that either. If he didn't use the mirror and turned the PJ on its side it would be brighter as mirrors are not 100% efficient although he would need another lens wouldn't he? |
Nope, the mirror is the final piece in the light path. Had he gone horizontal he wouldn't need another lens
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garyfritz
Joined: 08 Apr 2006 Posts: 12026 Location: Fort Collins, CO
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Link Posted: Tue Jun 23, 2020 2:57 am Post subject: |
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First-surface mirrors are 94-99% efficient. No worries there.
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Zebra
Joined: 02 Jul 2020 Posts: 91 Location: NJ USA
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Link Posted: Fri Jul 03, 2020 4:46 pm Post subject: |
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The guy in the video has an overly simplistic view of what makes a more detailed image on a projector (or TV). His assumption that more pixels automatically = more detail is wrong.
A higher pixel density only means you can sit closer or go larger before being able to see pixels.
There are a whole bunch of other factors that go into our perception of detail. The most important one is the quality of the content. I.e the quality of the footage captured and the bitrate of the final media. Dci movie files at the theater have a bitrate around 250mbps regardless if they are 2k or 4k. UHD Blu Ray has a 100mbps bitrate. 1080p Blu Ray is 40mbps. 4K Netflix is 15-25mbps - i.e. lower than 1080p Blu Ray. Quality and res are two different things.
The frame rate also makes huge difference. Try turning off frame interpolation on a 4k TV or projector and the image becomes indistinguishable from 1080p (with the same content). Or try and spot a difference between 1080i 120hz and 1080p 60hz. They look the same because you're seeing the same amount of info each second.
Contrast is also key. I'm talking about real contrast. Not that full on / full off nonsense. More real world contrast means more detail which is why LG's first 1080p Oled TVs looked way better than Sony's first 4k TVs. Try comparing a 1080p Pioneer Elite Kuro to a cheap 4k Walmart LCD. There's a reason why some hang on to 10+ year old tech...
With projectors, the lens quality is huge. Using a cheap plastic fresnel lens will cause a massive drop in quality. Quality glass is expensive and it goes up exponentially as they get larger. Commercial projectors use chips that are between 0.5" and 1.5". Using a 6" phone panel would require a way larger lens. Quality larger projector lenses sell for $5,000 - $20,000 on their own. With the cheap lens that guy used, more detail is the last thing you'd get.
Motion resolution is an issue with all LCD based displays. Without quality processing and frame interpolation, that 1080p or 4k image can look no better than old standard def with moving imagery. It's one of the many advantages CRT had over modern displays.
I think there are better ways of making a diy 4k projectors. Using 4 cheap used 1080p projectors off ebay with a video wall processor and an edge blending box, for example. Or using a gpu with 4 HDMI outputs.
If I was to use old phone screens for a diy projector, I'd probably forget about 4k and use 3 amoled phone screens with parts from an old 9" CRT projector. They're already somewhat set-up with quality lenses for larger screens at least.
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kal Forum Administrator
Joined: 06 Mar 2006 Posts: 17860 Location: Ottawa, Canada
TV/Projector: JVC DLA-NZ7
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Zebra
Joined: 02 Jul 2020 Posts: 91 Location: NJ USA
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Link Posted: Fri Jul 03, 2020 7:25 pm Post subject: |
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kal wrote: | Welcome to the forum Zebra and exactly right!
Unfortunately ignorant consumers like simple numbers. So when they see 4K they assume it's better than all 1080p. More is better right? and manufacturers cater to this simplistic view.
Don't get me started on the temporal resolution issue... We're not watching static windows desktops on our TVs projectors. Bitrate is incredibly important. Anyone remember superbit DVDs? https://en.wikipedia.org/wiki/Superbit
Kal |
Thanks
and yeah, most people do seem to like simple comparisons. It's amazing to me that people still choose projectors based on the stated contrast ratio and the rated lumens (even when they don't state how they were measured).
The idea that a projector can look worse on paper but perform better in reality is a stretch for most people. But... for some reason... they find it easy to believe that projection tech has advanced so much that their new $1500 LG or Viewsonic can perform better than projectors that cost $30,000 - $60,000 just 3-8 years ago... Even though no new projection display tech has been released in that time (I.e. we're still using Lcos, LCD and DLP).
Despite my best finger-puppet show explanations, the only way I've ever been able to convince anyone is by bringing them to my place to see what the image on a high end Barco, Christie or Sony looks like.
Still, the plus side is that there are more amazing bargains on 1080p kit for people like us. It's not uncommon to find 1080p projectors that cost $30,000-$100,000 + $5,000-$20,000 lenses for less than $2,000 on ebay.
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kal Forum Administrator
Joined: 06 Mar 2006 Posts: 17860 Location: Ottawa, Canada
TV/Projector: JVC DLA-NZ7
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Link Posted: Fri Jul 03, 2020 7:32 pm Post subject: |
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Zebra wrote: | Still, the plus side is that there are more amazing bargains on 1080p kit for people like us. It's not uncommon to find 1080p projectors that cost $30,000-$100,000 + $5,000-$20,000 lenses for less than $2,000 on ebay. |
We're coming full circle... I first contacted Curt Palme in the late 90s because I wanted a CRT projector and they were being dumped at the time for "better" digitals. Bought a Barco for around $2K that just a few years earlier was $20-30K.
Kal
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AnalogRocks Forum Moderator
Joined: 08 Mar 2006 Posts: 26690 Location: Toronto, Ontario, Canada
TV/Projector: Sony 1252Q, AMPRO 4000G
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Link Posted: Sat Jul 04, 2020 3:35 am Post subject: |
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kal wrote: | Zebra wrote: | Still, the plus side is that there are more amazing bargains on 1080p kit for people like us. It's not uncommon to find 1080p projectors that cost $30,000-$100,000 + $5,000-$20,000 lenses for less than $2,000 on ebay. |
We're coming full circle... I first contacted Curt Palme in the late 90s because I wanted a CRT projector and they were being dumped at the time for "better" digitals. Bought a Barco for around $2K that just a few years earlier was $20-30K.
Kal |
NOW you are preaching MY religion. Love Surplus!
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Zebra
Joined: 02 Jul 2020 Posts: 91 Location: NJ USA
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Link Posted: Sat Jul 04, 2020 6:15 pm Post subject: |
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AnalogRocks wrote: | kal wrote: | Zebra wrote: | Still, the plus side is that there are more amazing bargains on 1080p kit for people like us. It's not uncommon to find 1080p projectors that cost $30,000-$100,000 + $5,000-$20,000 lenses for less than $2,000 on ebay. |
We're coming full circle... I first contacted Curt Palme in the late 90s because I wanted a CRT projector and they were being dumped at the time for "better" digitals. Bought a Barco for around $2K that just a few years earlier was $20-30K.
Kal |
NOW you are preaching MY religion. Love Surplus! |
Can I get an amen!
Once you get a taste for high end projectors with high end glass, it's hard to go back. Surplus is the absolute best source. There's so many of these high end projectors that get bought for one-off projects and then get sold at pennies on the dollar. It's no surprise that small businesses who buy $50,000 projectors often go bankrupt too.
I got my first Barco / Projectiondesign F32 1080 viz sim in 2010, when it was still new tech, for $1500 with an $8000 short throw zoom lens with just 15 hours of total use. While others were aiming for 1000 calibrated lumens, I was enjoying close to 3500 calibrated and some of the most accurate colors on earth. The seller had 8 of them that had been bought for some type of video wall art exhibition thing that ended up not happening. It was a great living room projector with my black screen.
Anyone who thinks a new $2000 projector of today can match a $30,000-$60,000 of even 20 years ago is just wrong.
The trick is to not spend too much time reading reviews of the latest tech so you don't get tempted into buying inferior kit just to access to a few novelty features. HDR, for example, is a complete waste of time on projectors. It's not even that great on my Oled.
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kal Forum Administrator
Joined: 06 Mar 2006 Posts: 17860 Location: Ottawa, Canada
TV/Projector: JVC DLA-NZ7
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Link Posted: Sat Jul 04, 2020 7:13 pm Post subject: |
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Zebra wrote: | Anyone who thinks a new $2000 projector of today can match a $30,000-$60,000 of even 20 years ago is just wrong. |
20 may be pushing it. While I agree that the glass and many other aspects of expensive pro/commercial trade stuff is excellent, many (most? all?) commercial projectors are about light output first and sacrifice other things to get that amount of lumens. 20 years ago most digital projectors were also abysmal in the aspects we care about for image quality. So I think it would really depend on what you’re comparing. I remember seeing some very expensive cost no object HTs using digital projectors around that price range back in 2000-2004ish and the aspects that I like in picture quality were completely missing. The projectors were bright but had horribly elevated black levels and really bad contrast ratios (flat/lifeless image). Most had horrible screen door as well at that time. The owners thought they looked great as they had never seen anything better. I stuck with CRT until 2013 or so partially because it the only thing that met my needs. When we moved in 2011-2012 CRT wouldn't work in our layout so I went JVC LCOS.
My 2 cents.
Kal
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AnalogRocks Forum Moderator
Joined: 08 Mar 2006 Posts: 26690 Location: Toronto, Ontario, Canada
TV/Projector: Sony 1252Q, AMPRO 4000G
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Link Posted: Sat Jul 04, 2020 11:46 pm Post subject: |
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kal wrote: | Zebra wrote: | Anyone who thinks a new $2000 projector of today can match a $30,000-$60,000 of even 20 years ago is just wrong. |
20 may be pushing it. While I agree that the glass and many other aspects of expensive pro/commercial trade stuff is excellent, many (most? all?) commercial projectors are about light output first and sacrifice other things to get that amount of lumens. 20 years ago most digital projectors were also abysmal in the aspects we care about for image quality. So I think it would really depend on what you’re comparing. I remember seeing some very expensive cost no object HTs using digital projectors around that price range back in 2000-2004ish and the aspects that I like in picture quality were completely missing. The projectors were bright but had horribly elevated black levels and really bad contrast ratios (flat/lifeless image). Most had horrible screen door as well at that time. The owners thought they looked great as they had never seen anything better. I stuck with CRT until 2013 or so partially because it the only thing that met my needs. When we moved in 2011-2012 CRT wouldn't work in our layout so I went JVC LCOS.
My 2 cents.
Kal |
I own some of the 1999 JVC DILA's the rated contrast ratio was 250:1. I remember one pf the magazines measured the actual contrast ratio at 110:1. So yeah, let's sat they started getting better around 2005
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kal Forum Administrator
Joined: 06 Mar 2006 Posts: 17860 Location: Ottawa, Canada
TV/Projector: JVC DLA-NZ7
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Link Posted: Sun Jul 05, 2020 2:02 pm Post subject: |
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The first HT projector I saw in person that got me thinking "ok, they're on to something good finally" was the JVC DLA-RS1 around 2007 timeframe. 15,000:1 contrast ratio. Green was horribly out of spec (oversaturated) and with no CMS many were using Radiance video processors to tame it to Rec.709 standards. I saw it at a local HT guy's house who also had a Marquee CRT projector.
Kal
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