I suppose almost every OHP-ish double fresnel can be separated. I'm going to order one from Alan.Psionic said:
Yes. Just asked Alan.
A hard question. Since it has 14" focal length on both sides, I hardly can imagine the OHP that will work with this lens. It should be a big one. Better take some parts from your current OHP (if any) and build custom casing.
I have a receiver and those cheap a/v switch boxes are just that... cheap. I'd stay away from them.
My receiver is great... and besides... it's only used for audio. I dont pass any video through it. After thinking about it a bit more the 1154 isnt really expensive for what it does. I've paid over 150 for good s-video auto-switchers But I think I'm going to add a video scaler instead of simple component-RGB conversation. From what I'm reading the 9A62 doesnt pass video higher then 480p
My receiver is great... and besides... it's only used for audio. I dont pass any video through it. After thinking about it a bit more the 1154 isnt really expensive for what it does. I've paid over 150 for good s-video auto-switchers But I think I'm going to add a video scaler instead of simple component-RGB conversation. From what I'm reading the 9A62 doesnt pass video higher then 480p
9a62
I know it's only 480p, but I'm still waiting for a better detailed or better color screenshot to be posted. I want to do more testing using my computer DVD drive- but getting it to reliably play DVD's has been interesting!!! Can anyone recommend the best dvd software out there??????
I know it's only 480p, but I'm still waiting for a better detailed or better color screenshot to be posted. I want to do more testing using my computer DVD drive- but getting it to reliably play DVD's has been interesting!!! Can anyone recommend the best dvd software out there??????
viewsonic N6 video processor??
Hey Lifter-
You use the N6, dont you?
Does it scale 480p component video in to 1024x768 out?
Results???
Hey Lifter-
You use the N6, dont you?
Does it scale 480p component video in to 1024x768 out?
Results???
I think from past posts he had said that he didnt like it too much. The only good thing about the N6 from what I've read is that it converts Component - VGA. But if it scales the component video with good results... it may be what we're looking for.
Other then a scaler we could use something like the <a href="http://www.keydigital.com/detail.asp?Product_ID=KD-CTCA2">KDS KD-CTCA2</a>. It's like the 9A62 but passes 480p, 720p, 1080i/540p signals.
Other then a scaler we could use something like the <a href="http://www.keydigital.com/detail.asp?Product_ID=KD-CTCA2">KDS KD-CTCA2</a>. It's like the 9A62 but passes 480p, 720p, 1080i/540p signals.
So is the DIY Labs fresnel separable?
Is it a double fresnel?
In which OHP does it fit?
Can somebody with this lens comment?
(oh crap 2x post sorry!)
Is it a double fresnel?
In which OHP does it fit?
Can somebody with this lens comment?
(oh crap 2x post sorry!)
Psionic said:
yes i have that fresnel and it does seperate
Im not sure if its made for an ohp or not i wouldnt think so because of the long focal length, it would be a very large ohp
software DVD player
I like PowerDVD and it's one of the best at playing less than stellar DVD masters.
Hezz
I like PowerDVD and it's one of the best at playing less than stellar DVD masters.
Hezz
I have been following this DIY project with interest and have finally got to the point where i feel the need to ask a question so please bear with me....
With the frenels in parallel (i.e. split and the LCD in the middle) does the Fresnel have to be larger than the actual LCD?
Thanks for any help,
Matt
With the frenels in parallel (i.e. split and the LCD in the middle) does the Fresnel have to be larger than the actual LCD?
Thanks for any help,
Matt
msm said:
Ideally, Fresnels should be the same size as LCD (I mean the working area of fresnels, since all of them have some flat space around rigged area that is useless). If they are a bit bigger, this is not a problem. If they are much bigger, you just spend more money for fresnels and make your overall construction bigger without any visible improvemens.
I.e. 15" LCD has dimension of 9"x12". Thus, the fresnel with effective size of 9"x12" will be enough. Since it's almost impossible to find lenses of this size, one should use 12"x12" or slightly bigger lenses.
Of course - now i feel stupid for forgetting that the 15" is the diagonal size of the LCD 😱
I just need to source a 12x12 fresnell in England now... 🙂
Oh well, i look forward to actually getting started on this - i love these homebrew projects - not that many of mine reach completion but i have fun trying and i have a good feeling about this one 🙂
Thanks for the help
Matt
I just need to source a 12x12 fresnell in England now... 🙂
Oh well, i look forward to actually getting started on this - i love these homebrew projects - not that many of mine reach completion but i have fun trying and i have a good feeling about this one 🙂
Thanks for the help
Matt
Sorry I have been away. Work is crazy.
It makes sense that seperating the fresnels into singles and placing the lcd in the middle would give more brightness.
With a polarizing layer to the lcd and light striking the panel at a slight angle, I would guess that some brightness is lost.
What would be helpful? If someone could quantivtatively measure the amount of light striking the center of the screen (of a double fresnel/lcd arrangement) and compare that to the amount of light hitting the screen (of a single fresnel/lcd/single fresnel arrangement), we could see the amount of increase of brightness that we could expect.
I appreciate the "Wow" and "It's worth it" types of expressions, but we all judge differently. For those of you trying the new arrangement, how much brighter (subjectively) would you say it is?
Ken
It makes sense that seperating the fresnels into singles and placing the lcd in the middle would give more brightness.
With a polarizing layer to the lcd and light striking the panel at a slight angle, I would guess that some brightness is lost.
What would be helpful? If someone could quantivtatively measure the amount of light striking the center of the screen (of a double fresnel/lcd arrangement) and compare that to the amount of light hitting the screen (of a single fresnel/lcd/single fresnel arrangement), we could see the amount of increase of brightness that we could expect.
I appreciate the "Wow" and "It's worth it" types of expressions, but we all judge differently. For those of you trying the new arrangement, how much brighter (subjectively) would you say it is?
Ken
afan is totally right about the size. Bigger is fine, but more expensive. An oversize fresnel can recapture SOME wasted light that wasn't perfectly parallel going through the LCD.
The far edges of most fresnel typically contain a garbage margin around the edges (from where they were attached or are designed to be held). The should be masked off so that it doesn't cause light to go through the non-lens portion, creating random light (and lowering contrast).
As far as seeing the difference (subjectively), a picture of a screen showing a plain white image should really show this. A digital camera is much less accepting of differences in light than human eyeballs, so it may tend to exaggerate the dirrerences.
To see good before and after pics like this, take at least two: one from a "best seat" and one from off to the side. In this way you will be able to see how much of the hotspot is being caused by the screen, an how much by the projector itself.
BTW, the big obstacle in the non-parallel light is not the pre-polarizer. As a reflector, it won't be too much different 20 degrees off-axis, than straight on, but it is a factor.
The big obstacle for non-totally-parallel light is that light going throught the corners doesn't pass through the LCD twist material very well. Even panels that appear to have a wide angle of visibility accomplish this by some slight diffusion on exit or slightly spread the light on exit by other means. The still require light to come IN straight to the back of them.
To get a feel for this, get your "backless" panel plugged into a signal source of something all white ard hold it up and look through it at objects around the room.
Another great test (panel, no lenses, lamps, box, etc.) is to shoot a cheap laser pointer at the wall THROUGH the panel. See what happens when the light tries to go through diagonally.
[2] light spreading out as is goes through the corners has little chance
The far edges of most fresnel typically contain a garbage margin around the edges (from where they were attached or are designed to be held). The should be masked off so that it doesn't cause light to go through the non-lens portion, creating random light (and lowering contrast).
As far as seeing the difference (subjectively), a picture of a screen showing a plain white image should really show this. A digital camera is much less accepting of differences in light than human eyeballs, so it may tend to exaggerate the dirrerences.
To see good before and after pics like this, take at least two: one from a "best seat" and one from off to the side. In this way you will be able to see how much of the hotspot is being caused by the screen, an how much by the projector itself.
BTW, the big obstacle in the non-parallel light is not the pre-polarizer. As a reflector, it won't be too much different 20 degrees off-axis, than straight on, but it is a factor.
The big obstacle for non-totally-parallel light is that light going throught the corners doesn't pass through the LCD twist material very well. Even panels that appear to have a wide angle of visibility accomplish this by some slight diffusion on exit or slightly spread the light on exit by other means. The still require light to come IN straight to the back of them.
To get a feel for this, get your "backless" panel plugged into a signal source of something all white ard hold it up and look through it at objects around the room.
Another great test (panel, no lenses, lamps, box, etc.) is to shoot a cheap laser pointer at the wall THROUGH the panel. See what happens when the light tries to go through diagonally.
[2] light spreading out as is goes through the corners has little chance
So , what you are saying is that the loss in brightness is from the light attempting to pass throught the panel's cells from a less that exact perpendicual angle. The "corners" of the cells are diffusing the light?
Ken
Ken
Re: 480p 640x480
Nice job, and great find with the splitting of the fresnels. I wish I paid more attention because I would have gladly done it (my Elmo fresnel is so scratched I could care less if it didn't work).
I have the N6 and that's what it does indeed, but don't get it. There are much cheaper devices that do the same thing. The N6 has a worthless NTSC tuner built in, accepts a VGA input for overlay purposes, and has a crappy remote that looks cool in pictures. Not worth the extra $200. If you can, I would recommend using a PC to play your DVD's. That is a step up from converting component video to RBG.
EDIT:
Actually, there is one nice thing about the N6. You can put it in 16:9 mode without changing any resoltion. This is pretty useful since there's no vertical size control for the the 1545 (or any other LCD to my knowledge).
proto5 said:
Nice job, and great find with the splitting of the fresnels. I wish I paid more attention because I would have gladly done it (my Elmo fresnel is so scratched I could care less if it didn't work).
I have the N6 and that's what it does indeed, but don't get it. There are much cheaper devices that do the same thing. The N6 has a worthless NTSC tuner built in, accepts a VGA input for overlay purposes, and has a crappy remote that looks cool in pictures. Not worth the extra $200. If you can, I would recommend using a PC to play your DVD's. That is a step up from converting component video to RBG.
EDIT:
Actually, there is one nice thing about the N6. You can put it in 16:9 mode without changing any resoltion. This is pretty useful since there's no vertical size control for the the 1545 (or any other LCD to my knowledge).
gui_999 said:
Believe it or not, that is without a doubt the best solution for people who don't want to have to use a computer to play DVDs, and for people who don't want to spend money on a DVD player with a VGA output.
Just remember that after you apply the patch you won't be able to see the Xbox dashboard or DVD video on a regular analog TV. But games work fine, and you can undo the patch if you need to.
Re: viewsonic N6 video processor??
Hehe, yeah, that's what it does. It scales any type of analog input (480i, 480p, 720p, 1080i) to whatever computer-friendly output you want (640x480 - 1280x1024). It supports a few widescreen resolutions (like 1280x768), but this will fill the entire screen and be disproportioned, meaning it was meant for widescreen monitors. Instead, you can put it 1024x768 mode (which is what we'd want with the 1545), and then select 16:9. This makes the LCD think that it's recieving a full 3:4 XGA image, but the top and bottom are just black bars and the whole source image (DVD for example) fits within it. I hope that makes sense.
I know it's useful, but if your at all interested in using an anamorphic lens, I would consider getting a cheaper transcoder. There are devices for under $200. The N6 is like $380. That being said, I would recommend forgetting about the whole component thing and use a PC DVDrom. Better yet, get an Xbox, a modchip, and a VGA cable for it (still a lot less than the N6). That gives you all the benefits of a standalone player without the need for a transcoder.
proto5 said:
Hehe, yeah, that's what it does. It scales any type of analog input (480i, 480p, 720p, 1080i) to whatever computer-friendly output you want (640x480 - 1280x1024). It supports a few widescreen resolutions (like 1280x768), but this will fill the entire screen and be disproportioned, meaning it was meant for widescreen monitors. Instead, you can put it 1024x768 mode (which is what we'd want with the 1545), and then select 16:9. This makes the LCD think that it's recieving a full 3:4 XGA image, but the top and bottom are just black bars and the whole source image (DVD for example) fits within it. I hope that makes sense.
I know it's useful, but if your at all interested in using an anamorphic lens, I would consider getting a cheaper transcoder. There are devices for under $200. The N6 is like $380. That being said, I would recommend forgetting about the whole component thing and use a PC DVDrom. Better yet, get an Xbox, a modchip, and a VGA cable for it (still a lot less than the N6). That gives you all the benefits of a standalone player without the need for a transcoder.
Fourth post in a row. Sorry.
About the Alan fresnel. Cruser (first guy to successfully use the 1545) built an entire enclosure using that thing. He had poor results. He lost brightness from the fresnel being so far away from the bulb. He also lost brightness from the objective lens being so far away from the panel, it really shrunk the picture. The only good thing about it was that it was cool to the touch.
I think 14" is too far away from the bulb. I think the ideal FL for a bottom fresnel is 8-10", which would be just above the stage glass on most OHPs.
About the Alan fresnel. Cruser (first guy to successfully use the 1545) built an entire enclosure using that thing. He had poor results. He lost brightness from the fresnel being so far away from the bulb. He also lost brightness from the objective lens being so far away from the panel, it really shrunk the picture. The only good thing about it was that it was cool to the touch.
I think 14" is too far away from the bulb. I think the ideal FL for a bottom fresnel is 8-10", which would be just above the stage glass on most OHPs.
Lifter said:
Well I have a moded xbox with the Evolution dashboard. When I need to play a DVD, I have to run the MS dashboard from the Evolution menu. So I could put an other menu in Evolution that point to the patched xbe, so I have the 2 version of the dashboard
N6
Lifter:
You mention cheaper ways to do it than the N6 but didn't say what. Also I'd love to see some screenshots comparing :
1: component video to VGA with 9a62 box- 640x480. (my setup)
2: component video to XGA with your N6 box.
3: HTPC to XGA
I can do #1 and #3, but not #2.
Thanks-
Lifter:
You mention cheaper ways to do it than the N6 but didn't say what. Also I'd love to see some screenshots comparing :
1: component video to VGA with 9a62 box- 640x480. (my setup)
2: component video to XGA with your N6 box.
3: HTPC to XGA
I can do #1 and #3, but not #2.
Thanks-
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