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Pzyked
Joined: 02 Apr 2017
Posts: 30
Location: Sweden
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 Link Posted: Mon Dec 25, 2017 8:24 pm Post subject: |
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Today with 4K UHD and HDR, MTF will probably be preferred before on off. Good on off around 20000:1 does the job more than enough for a perfect image.
I have to say I prefer on off. But also prefer the perfect black when there are information in the movie. Total darkness is nice to have in a projector when the brightness is 0, but maybe the absolute least important to the whole picture quality. So the combination MTF, on off and the contrast when there is info in the picture are for shore the best combination.
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gjaky
Joined: 05 Jun 2010
Posts: 2790
Location: Budapest, Hungary
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| Link Posted: Mon Dec 25, 2017 9:48 pm Post subject: |
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| jbltecnicspro wrote: | | gjaky wrote: | | I think this is also a matter of preference. I have a friend who is an avid DLP fan, he has a fine collection of top end DPI, Projection design and Barco 1 and 3 chip projectors. He checked out the VW5000 as well and he did not like it either, he complained about uneven colour response and poor MTF. But for example this guy is an MTF nut, and not interested in the on/off contrast at all |
Wow. Never thought I'd see the day when someone would take MTF over contrast. I always assumed that those who poopoo on/off contrast haven't seen a projector with proper on/off and didn't know what they were missing out on. |
We have checked of eachother's projector of course and he complained about the missing fine details of the XG135 LC (what I had that time) due to the poor MTF. And I complained about the poor on/off contrast of the DLP. Also rainbow effect distracts me, so for me 3 chipper would be the only option, but achieving good on/off contrast on a DLP is always painful.
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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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jbltecnicspro
Joined: 23 Apr 2016
Posts: 512
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| Link Posted: Mon Dec 25, 2017 10:07 pm Post subject: |
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| gjaky wrote: | | jbltecnicspro wrote: | | gjaky wrote: | | I think this is also a matter of preference. I have a friend who is an avid DLP fan, he has a fine collection of top end DPI, Projection design and Barco 1 and 3 chip projectors. He checked out the VW5000 as well and he did not like it either, he complained about uneven colour response and poor MTF. But for example this guy is an MTF nut, and not interested in the on/off contrast at all |
Wow. Never thought I'd see the day when someone would take MTF over contrast. I always assumed that those who poopoo on/off contrast haven't seen a projector with proper on/off and didn't know what they were missing out on. |
We have checked of eachother's projector of course and he complained about the missing fine details of the XG135 LC (what I had that time) due to the poor MTF. And I complained about the poor on/off contrast of the DLP. Also rainbow effect distracts me, so for me 3 chipper would be the only option, but achieving good on/off contrast on a DLP is always painful. |
The only single-chipper that achieves good contrast (and good rainbow performance because of its true 6x color wheel speed - 360hz) is the Runco LS-5, and it still cheats to get there. With a dynamic iris, it achieves about 10,000:1 contrast. Without the iris it's only capable of doing 2500:1. But still, the iris is quite good from what I've read, and its sharp, and its color points are pretty much on the mark for REC 709.
Not sure why they haven't been able to produce a DLP with a high native contrast. My Yamaha DPX-1200 is still probably the best at around 4,000:1 and it doesn't have a dynamic iris.
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Pzyked
Joined: 02 Apr 2017
Posts: 30
Location: Sweden
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| Link Posted: Tue Dec 26, 2017 9:19 am Post subject: |
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DLP has its positive sides, and like jbltecnicspro sais way under 4000:1 is correct. I will say that its not good enough.
I feel that you minimum need 15000:1 or higher native. New Sony 4Ks have this. If you need more on off JVC can do this.
But then not native 4K. But on off between 20-150000:1 native depending on iris setting for wished light output. But any crt will manage better total fade to black. The same effect as laser projectors when turning off laser light when no light.
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redfox001
Joined: 16 Mar 2009
Posts: 2251
Location: The Netherlands
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| Link Posted: Wed Dec 27, 2017 3:05 pm Post subject: |
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But these newer Sony seem to have 4 times the lumens a CRT has. Now contrast says something about the max lumens divided by the blacklevels so to know a little more how this number relates to blacklevels you should devide the 15000 by 4 making it 3750. This would be the contrast if the Sony was not allowed to go any brighter than the CRT. So that makes CRT black levels something like 10 times better (30000 native contrast for the 909).
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701s->runco933->8500ultra->hd1->hd350->vw100->cinemax+919sp+3x919+9500mp->cinemax+919sp(modded)+kuro600a
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pj-toso
Joined: 19 Mar 2015
Posts: 69
Location: Norway - Oppland
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| Link Posted: Wed Dec 27, 2017 9:34 pm Post subject: |
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| redfox001 wrote: | | But these newer Sony seem to have 4 times the lumens a CRT has. Now contrast says something about the max lumens divided by the blacklevels so to know a little more how this number relates to blacklevels you should devide the 15000 by 4 making it 3750. This would be the contrast if the Sony was not allowed to go any brighter than the CRT. So that makes CRT black levels something like 10 times better (30000 native contrast for the 909). |
Your analogy is flawed here, because u can close the manual iris to match the crt, and that makes the native contrast even higher like over 20000:1.
I have both a Barco Cine 9 and JVC RS400 and enjoy both. When it comes to black level it is better for me, I get the JVC nearly perfect both gamma and greyscale down to bar 17(0.5 ire) - it makes for very detailed and 3d picture in low apl scenes.
Why do I have a crt. Because it is something special, I cant quantify it, but I enjoy to watch it. So for me I enjoy both old and new technology.
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Disclaimer: My postings are subjective and not facts.
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jbltecnicspro
Joined: 23 Apr 2016
Posts: 512
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| Link Posted: Wed Dec 27, 2017 10:56 pm Post subject: |
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| redfox001 wrote: | | But these newer Sony seem to have 4 times the lumens a CRT has. Now contrast says something about the max lumens divided by the blacklevels so to know a little more how this number relates to blacklevels you should devide the 15000 by 4 making it 3750. This would be the contrast if the Sony was not allowed to go any brighter than the CRT. So that makes CRT black levels something like 10 times better (30000 native contrast for the 909). |
Not at all. Like pj-toso says on most units you can close down the iris to match the black levels of a CRT. With JVC projectors you really can have your cake and eat it too.
I think this works the same for all projectors because even my Yamaha's contrast is the best when its iris is fully closed down. According to the manual, the fully-open iris gets only around 2500:1 and fully closed it's spec'd at 5000:1. Realistically you're looking at going from 2300:1 to 4300:1 but the principle is still the same.
The newer digitals really can achieve CRT-crushing contrast, along with more lumens to power even bigger screens. Again - have your cake and eat it too.
That said... I'm still of the CRT superiority camp. I'll always cherish the look of an analog display over a digital any day of the week. But so long as I can get the digital display really close, I'm happy. 
If I had it my way, I'd have a nice JVC for the big screen movie nights (talking 120 inches or so), and for the more intimate viewing sessions, I'd have a color-corrected G90 on a 92-100 inch Stewart.
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redfox001
Joined: 16 Mar 2009
Posts: 2251
Location: The Netherlands
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| Link Posted: Wed Dec 27, 2017 11:26 pm Post subject: |
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| pj-toso wrote: | | redfox001 wrote: | | But these newer Sony seem to have 4 times the lumens a CRT has. Now contrast says something about the max lumens divided by the blacklevels so to know a little more how this number relates to blacklevels you should devide the 15000 by 4 making it 3750. This would be the contrast if the Sony was not allowed to go any brighter than the CRT. So that makes CRT black levels something like 10 times better (30000 native contrast for the 909). |
Your analogy is flawed here, because u can close the manual iris to match the crt, and that makes the native contrast even higher like over 20000:1.
I have both a Barco Cine 9 and JVC RS400 and enjoy both. When it comes to black level it is better for me, I get the JVC nearly perfect both gamma and greyscale down to bar 17(0.5 ire) - it makes for very detailed and 3d picture in low apl scenes.
Why do I have a crt. Because it is something special, I cant quantify it, but I enjoy to watch it. So for me I enjoy both old and new technology. |
Ok I did not know the iris could be set to a fixed value that also lowers the blacklevel. Nice, seems like something I would do with a digital.
But what holds me back the most is that I did not enjoy my HD350 as much as my CRT. It became better with my VW100 but that one had terrible blacks. I suspect the light spectrum from these projectors. The VW100 was the better with xenon lamp. The HD350 had a UHP lamp and was terrible to me on the long run.
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pj-toso
Joined: 19 Mar 2015
Posts: 69
Location: Norway - Oppland
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| Link Posted: Wed Dec 27, 2017 11:42 pm Post subject: |
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| redfox001 wrote: | | pj-toso wrote: | | redfox001 wrote: | | But these newer Sony seem to have 4 times the lumens a CRT has. Now contrast says something about the max lumens divided by the blacklevels so to know a little more how this number relates to blacklevels you should devide the 15000 by 4 making it 3750. This would be the contrast if the Sony was not allowed to go any brighter than the CRT. So that makes CRT black levels something like 10 times better (30000 native contrast for the 909). |
Your analogy is flawed here, because u can close the manual iris to match the crt, and that makes the native contrast even higher like over 20000:1.
I have both a Barco Cine 9 and JVC RS400 and enjoy both. When it comes to black level it is better for me, I get the JVC nearly perfect both gamma and greyscale down to bar 17(0.5 ire) - it makes for very detailed and 3d picture in low apl scenes.
Why do I have a crt. Because it is something special, I cant quantify it, but I enjoy to watch it. So for me I enjoy both old and new technology. |
Ok I did not know the iris could be set to a fixed value that also lowers the blacklevel. Nice, seems like something I would do with a digital.
But what holds me back the most is that I did not enjoy my HD350 as much as my CRT. It became better with my VW100 but that one had terrible blacks. I suspect the light spectrum from these projectors. The VW100 was the better with xenon lamp. The HD350 had a UHP lamp and was terrible to me on the long run. |
Both JVC and Sony has advanced a lot since the HD350. Especially the possebilty to get almost perfect gamut, gamma and greyscale. The lamps has also gotten better regarding spectrum, light loss and stability. But if the UHP spectrum bothered u - I quess it still will.
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Disclaimer: My postings are subjective and not facts.
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jbltecnicspro
Joined: 23 Apr 2016
Posts: 512
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| Link Posted: Thu Dec 28, 2017 12:05 am Post subject: |
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Yeah, HD-350 is an RS-15 right? We're several generations beyond that now.
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redfox001
Joined: 16 Mar 2009
Posts: 2251
Location: The Netherlands
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| Link Posted: Thu Dec 28, 2017 7:33 am Post subject: |
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Apart from the lamp CRT has a natural gamma response on lowering voltage in the video. My guess is that these chips have trouble emulating that gamma response leading to worse fading to black as the technology can't make the very small steps. Probably also banding.
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pj-toso
Joined: 19 Mar 2015
Posts: 69
Location: Norway - Oppland
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| Link Posted: Thu Dec 28, 2017 1:35 pm Post subject: |
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| redfox001 wrote: | | Apart from the lamp CRT has a natural gamma response on lowering voltage in the video. My guess is that these chips have trouble emulating that gamma response leading to worse fading to black as the technology can't make the very small steps. Probably also banding. |
What? This is even more wrong than your statement regarding contrast/blacklevels on digitals.
Crt dosent have correct/natural gamma. Crt is struggling under 20 ire with large error in gamma/greyscale.
For example my JVC has almost perfect gamma/greyscale under 10 ire measured on 0.5, 1, 2, 3, 4, 5 and 10 ire it measures with under 1 in Delta, resulting in incredibly diemensionality og detail in low apl scenes like Zero Dark Thirty and Harry Potter.
My friends JVC RS540 is even better. With 16 foot-lambert on a 106 diagonal screen, he has 100000:1 in native contrast making for inky blacks in low apl scenes, better than any crt due to better ansi-contrast and better gamma/greyscale tracking.
Even for this I prefer to watch crt sometimes due the fact I like how the phosphor produce the picture on the screen, but I cant give a scientific reason for hit.
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redfox001
Joined: 16 Mar 2009
Posts: 2251
Location: The Netherlands
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| Link Posted: Thu Dec 28, 2017 6:10 pm Post subject: |
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I think part of the secret is in that the CRT green spectral distribution has blueish green. Your eyes are most sensitive to this green when the light is low (scotopic vision). The UHP lamp is pretty much wrong in this area.
I know from my own experience that I can have low light scenes with very much detail in a very dark environment. I attribute it to the way I got the green gamma right into the dark. Very natural, red does not play a visible role there and blue almost neither. Your UHP lamp does have a little beter blue though but not enough to enjoy the dark side as much:)
Anyway be happy with it I have had these discussions for to long. I am happy with my CRT.
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701s->runco933->8500ultra->hd1->hd350->vw100->cinemax+919sp+3x919+9500mp->cinemax+919sp(modded)+kuro600a
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pj-toso
Joined: 19 Mar 2015
Posts: 69
Location: Norway - Oppland
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| Link Posted: Thu Dec 28, 2017 11:25 pm Post subject: |
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| redfox001 wrote: | I think part of the secret is in that the CRT green spectral distribution has blueish green. Your eyes are most sensitive to this green when the light is low (scotopic vision). The UHP lamp is pretty much wrong in this area.
I know from my own experience that I can have low light scenes with very much detail in a very dark environment. I attribute it to the way I got the green gamma right into the dark. Very natural, red does not play a visible role there and blue almost neither. Your UHP lamp does have a little beter blue though but not enough to enjoy the dark side as much:)
Anyway be happy with it I have had these discussions for to long. I am happy with my CRT. |
What we 100% agree on is that a good color-filtered 9 inch crt projector is damn good, pleasant, easy on the eyes and enjoyable to watch.
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Disclaimer: My postings are subjective and not facts.
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kuquet
Joined: 22 Oct 2017
Posts: 6
Location: Europe France
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| Link Posted: Sat Feb 10, 2018 11:23 am Post subject: |
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| Francisco wrote: | Finally ! after massive testing with split pack cable attached, and short connect cables directly to motherboard one by one I found the fault!
It's connector J40 + and - Filament, G1 and G2. There is some kind of filtering on the extension boards for these connectors.
Attached those directly onto motherboard and the rest of cabling went trough extension cable gave me flat-out gamma and 3ftl more light on max contrast. Exactly what I was missing. I don't know if it's just a fault on my particular split-pack unit or maybe all Barco 909 split packs. Nevertheless I will make a short connection of less than 50cm to connect directly onto the motherboard, and all should be fine 
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Hi Francisco
I have one 909 split, it's starting but no picture, It's comes from one picture wall. on this extension board there's split or no-split jumper. I think it's the reason of no picture?
Do you know how to setup this board? or other idea ?
regards
Thierry (Fr)
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Francisco
Joined: 05 Apr 2007
Posts: 305
Location: The Netherlands
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