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All about lenses (specs/datasheets/pictures/etc.)
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gjaky



Joined: 05 Jun 2010
Posts: 2570
Location: Budapest, Hungary


PostLink    Posted: Sun May 18, 2014 3:06 pm    Post subject: Reply with quote


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It was said to me that the HD145 has less haloing than HD6C-ML, but I wasn't convinced with that, it was quite the same for me.

By the way lens haloing is always round shaped, what you talk about as "banding" isn't caused by the lens, it is made by the projector. It is usualy referred here as "streaking" it can be originated by numerous ways: some projectors are downright introduce this kind of problem (barco 808, sony 1292), but it can be caused by incorrect signal timings as well.

_________________
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
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mc86



Joined: 20 Sep 2008
Posts: 760
Location: pittsburgh, pa

TV/Projector: ECP 4500 (Vidikron box), ECP4500+, wanting 07MS/07MTS, evaluating pc soft-blend


PostLink    Posted: Thu Jun 11, 2015 2:55 am    Post subject: Reply with quote

Two summers ago I had a little fun and tore apart a HD6C lens. I thought I'd posted pictures of these but didn't find it real quickly. Apologies if I'm re-posting. Here are a few of the pics, just for fun. About a half-dozen individual lenses of complex geometries going into one assembly -- crazy stuff. If someone liked optics, I'm sure some of the free ray tracing packages would let you reconstruct the light path for at least a single given wavelength, at least.

Matt



000_1111.JPG
 Description:
outside case at top, internal lens retainer/spacing tube, the lenses themselves, roughly in order/spacing as if installed
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000_1111.JPG



hd-6c sketch.JPG
 Description:
rough sketches of the crazy shapes these things are
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hd-6c sketch.JPG



000_1112.JPG
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lenses without spacers/body they go inside
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000_1112.JPG


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tschaeikaei



Joined: 08 Apr 2013
Posts: 464
Location: Germany/Saarland


PostLink    Posted: Tue Nov 03, 2015 8:20 am    Post subject: Reply with quote

Did someone tr to exchange the HD-145 front element glass with one out of a HD6C?
I have both lens types here, but the front (screen side) elements of the HD-145 are scratched.
I could try, but i have no screen i could point it to, nor is the projector set up correctly.
They look the same.

Regards, Julian

PS: I think i saw a thread aobut this somewhere but cannot find it.

_________________
2 Marquee 8500U 2001 P43 | Barco 801s LC | NEC 9PG
Self-build 15"-LCD Beamer with 400W HRI bulb
small Teufel 5.1 Audio | HTPC | Pioneer HPM 100
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cmjohnson



Joined: 03 Apr 2006
Posts: 5180
Location: Buried under G90s


PostLink    Posted: Tue Mar 22, 2016 4:12 am    Post subject: Reply with quote

Just because there has been some interest in the elusive Surfbird-1 lens, I'm posting here to make mention of the fact that I just purchased one of these lenses and will be posting a practical evaluation of it shortly after it's in my hands.

I do not expect it to be very versatile, but I expect it to be very good for its intended application.

I'll leave off on any further speculation and post my results when I have them.
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cmjohnson



Joined: 03 Apr 2006
Posts: 5180
Location: Buried under G90s


PostLink    Posted: Wed Mar 23, 2016 7:40 pm    Post subject: Reply with quote

Incidentally, I found out that the Elcan manufactured HD-10L lenses used by VDC in late production Marquee Ultras started to appear in 2009. If you're seeking out that type of lens on a surplus projector, they'll only be found on SOME 2009 manufactured Marquees, and probably on all later ones.
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cmjohnson



Joined: 03 Apr 2006
Posts: 5180
Location: Buried under G90s


PostLink    Posted: Fri Jun 24, 2016 2:14 am    Post subject: Reply with quote

I recently got two (not a set, just two) of the Wigeon type lenses. Tried one out and discovered that they'd be fine
for a rear projection application if you don't need a big picture. Super short throw, maybe three feet at most, screen size
about 40" diagonal.

But nobody would complain about the brightness on a screen that small.

If anybody wants one or two Wigeon lenses, I'll let them go CHEAP. REALLY cheap. Maybe you have a third and are just dying to
use a CRT projector in an RP application, maybe for your video game console cabinet.
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racerxnet



Joined: 20 Jun 2007
Posts: 360
Location: Illinois


PostLink    Posted: Sat Jul 16, 2016 4:27 pm    Post subject: Reply with quote

I will be getting the NEC Quail lenses for trial on my 8500. These are supposedly better than the HD144's on it now. What type of shots do you think I should take to see if it resolves better? 1 pixel for vertical/horizontal, starburst, others?

MAK
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gjaky



Joined: 05 Jun 2010
Posts: 2570
Location: Budapest, Hungary


PostLink    Posted: Sat Jul 16, 2016 6:33 pm    Post subject: Reply with quote

racerxnet wrote:
I will be getting the NEC Quail lenses for trial on my 8500. These are supposedly better than the HD144's on it now. What type of shots do you think I should take to see if it resolves better? 1 pixel for vertical/horizontal, starburst, others?

MAK


I'd suggest to check on full screen small sized text (readability). But generally relying on fine detail resolution always implies CRT (raster) setup and bandwidth, which is not best.
There are several ways on the other hand to qualify a lens, the "resolution" is the sum of the various imperfections (aberration) of the lens system, in case the lenses for CRT the so-called spherical aberration is the most prominent of these.

You can check how smooth the lens quality with bare eye. To do this project a dot pattern, decrease contrast so you can see conveniently to the lens at the screen (focus) distance. At the focus distance the whole area of the lens is covered by a single dot as you can see, now carefully moving back and forth and left right you can see how the dot "occupies" the lens, it is a bit looking like a solar eclipse, and should be a smooth progress. Insted you'll see concentric circles and various distortions , that directly reflects to the unsmoothness of the lens surfaces. You can bet the smoother the better.

Also there is a method to check the spherical aberration of the lens. This requires a plain white paper sheet. Again display a dot pattern and see with the paper sheet how the blob (the dot) looks like in under- and overfocus positions. The more even blob you see the better the lens is, you most likely will see the blob will be more concentrated at the edges...

I'd suggest to compare the two lenses in these two regards. In fact I'd put the HD144 uncolored on the green tube, and put the quail blue lens to the red tube, so you can directly compare these qualities of the lens. However this build quality may even vary between the individual lenses.

_________________
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
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cmjohnson



Joined: 03 Apr 2006
Posts: 5180
Location: Buried under G90s


PostLink    Posted: Fri Mar 03, 2017 3:11 am    Post subject: Reply with quote

Another way to check the quality of a lens is simply to shine a bright LED light into it, one with a SINGLE bright LED, and look at the image on a white surface placed just behind the lens in question. Look for concentric striations and other artifacts of imperfect lens shaping.

A simple way to do this is to shine said flashlight into the C element of a Marquee tube assembly with no lens on it. As you move the light nearer to the perimeter of the C element, you will see these concentric ring striations which are high order (small) defects in the shape of the C element. Virtually any lens element can be evaluated for gross errors and defects in this manner.

Shining the same LED flashlight through the lens and looking at the focused image of the light's LED source is also a useful way to evaluate image quality. I just did this and used three different lenses in the comparison.

Lens 1, my very nice Nikon 200-500mm zoom telephoto lens, which resolved by far the sharpest image. Lens 2 is a first or second generation Minolta DLP lens intended for not more than 1280x1024 resolution projectors, and this gave a sharp image but not quite as sharp as the Nikon camera lens. Lens 3, an HD-10F, which comparatively speaking was really quite pooor, but I do not know if that was due to some issue with the lens being so much larger in its physical diameter than the others, or if it really is related to the resolution quality of the lens.
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Mr Jaeger



Joined: 24 Mar 2015
Posts: 41



PostLink    Posted: Mon Mar 06, 2017 9:35 am    Post subject: Reply with quote

1280x1024 resolution is max on almost every CRT lens with respectable MTF, that I know of. Like I told you CMJ this resolution 1280x1024 was hallelujah resolution at that time when CRT arrived. And wont be better with a bright LED light test. But you saw the result.

And CRT manages even to show 720P with extremely poor MTF. 720P around 30% MTF. The higher the resolution on CRT the less MTF. But if you favor low MTF showing 1080P or 720P on your CRT good for you Smile Its not wrong to like CRT.

So if you prefer correct 1080P resolution you must have as high MTF as possible. And CRT even with higher BW added in the video chain the lenses will be the weakest link. And MTF at 1080P around 10-20% on every 9" CRT.

50% MTF or higher manages the shown resolution well, would be nice to start there I think. Smile

50% MTF is also the minimum requires for lenses to get "green" light on the resolution tried today, different on CRT??? Smile
Wild guess, not.
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gjaky



Joined: 05 Jun 2010
Posts: 2570
Location: Budapest, Hungary


PostLink    Posted: Tue Apr 25, 2017 4:56 pm    Post subject: Reply with quote

I've only read about these lenses before, but now I xame accross one set of HD-18 in machined METAL housing out of a Sony G70, my HD-18 on the XG135LC had plastic case. Probaly won't add to optical performance, but this sure feels better than the plastic version.




_________________
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
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cmjohnson



Joined: 03 Apr 2006
Posts: 5180
Location: Buried under G90s


PostLink    Posted: Wed Apr 26, 2017 3:06 am    Post subject: Reply with quote

I've learned that there's a lens type called "red bird" which is used in some simulator projectors, and it is interesting in that it uses a much larger C element than we find in our 9" CRT projectors. If that's a 5" C element, these take a C element that's about 7" in diameter, much larger indeed.

I hope to get a little more information about them just for archival purposes.

I have seen Barco housings (looks like modified 909 housings) that use these larger C elements.
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gregstv



Joined: 27 Aug 2007
Posts: 616
Location: Australia


PostLink    Posted: Wed Apr 26, 2017 5:17 am    Post subject: Reply with quote

What did Barco use on their 12 inch projectors?
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km987654



Joined: 25 Jul 2007
Posts: 2730
Location: Australia

TV/Projector: Barco BG809s


PostLink    Posted: Wed Apr 26, 2017 9:24 am    Post subject: Reply with quote

gregstv wrote:
What did Barco use on their 12 inch projectors?


Buckets Laughing

HD-210 if the below is correct. Scroll down about 2/3 way.

http://www.curtpalme.com/forum/viewtopic.php?t=12307&highlight=812
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Rattanee



Joined: 18 Jan 2015
Posts: 193



PostLink    Posted: Tue May 16, 2017 5:40 am    Post subject: Reply with quote

Does anyone know the C-element to Lens distance for the HD18? Specifically the distance between the forward rim of the C-element and the base of the lens barrel.
_________________
Watching atm: Barco Cine 8 Onyx (HD-18 modded)
Working on atm: Barco 808s --> Cine8 Onyx conversion
Retired/shelved units: 2xNEC 9PG, 2xNEC 6PG Plus, Barco Vision 600, Sony VPH-1021
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Pokemon640



Joined: 28 Jul 2015
Posts: 47
Location: Greece


PostLink    Posted: Wed Oct 11, 2017 8:48 am    Post subject: Reply with quote

It's the first time that i have seen this model no.
IORA.2 for 9'

http://www.ebay.com/itm/LOT-OF-3-BARCO-909-IORA-2-9-CRT-LENS-SONY-G90-VDC-9500-/192325736965

any information available ? throw distance ? screen width ?
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