CurtPalme.com Home Theater Forum

[innof]

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Hello to everyone

I would like to kindly beseech your insight here; Can a Marquee 8500 effectively resolve 1080P?

And, what would be the maximum screen size achievable without compromising quality /performance?

In anticipation of your replies, Thank You!

(P.S. Curt - I sent you a PM)

[AnalogRocks]

Do you have a scaler?

[AnalogRocks]

Do you have a scaler?

[Meemil]

Depends of your PJ's age. Older models are starting to dump the caps and other electronics and 1080p is overall pretty demanding task. I'd recommend sticking with 1080i. The advantage is being able to run at higher refresh (72hz, 96hz) while not going over the bandwidth and sacrificing detail.

Check the optics too, stock lenses (HD-8) have a tad lackluster performance
Also as Analog hinted, scaler or HTPC is a wise idea so you can experiment and see yourself.

Keep in mind, these tips are coming from a quite unexperienced individual in this field

[gjaky]

A well setup 8500 produce visible scanlines at 720P so a higher resolution is possible than that. If you can do 1080i 96Hz that would be probably your best choice indeed, but if you don't have a HTPC or scaler the Marquee accomodates quite well with standard 1080P as well even though it may not fully resolve it.

[innof]

Hello again to everyone. And, Thank You Very Much for having kindly taken the time to reply, I do sincerely appreciate it.

I picked this projector up today. It was at a retirement home and was put into "indefinite" storage in a basement locker; I have claimed as my own personal property now with the blessing of an administrator whom was delighted to be rid of it.

This unit has Delta HD-8 / Rev. B lens' installed and the seem to have a colour element on them (both red and green from what I can tell; If there is one on the blue, it is indiscernible to me). These were purchased from a member on here on the forum many moons ago (if memory serves me correctly, the red one arrived damaged and I was never accordingly restituted the money owed to from from the mishap by the seller.........).

The production tag on the chassis says August 1997. However, if memory serves me correctly, this unit had brand new factory tubes installed (maybe 10 years ago)?

Does this in any way influence the dynamic?

[cmjohnson]

There's never a color correction element on the blue tube. It's not necessary.

For red and green to have been corrected on an 8500, that's always something done by hobbyists as there's no factory option for that. It could be done by tinting the glycol in the cooling cell that's permanently attached to the CRT, or it may be a sheet of tinted red stage lighting gel that's been installed.

If you need a tube I've got stock on all colors. You'll have to transfer over the color correction mod, though.

[innof]

Hello. Actually, these colour lens definitely look factory original; There is a metal ring (looks like machined aluminium) fitted around their circumference which is serving to have them to properly sit within the black housing.

As I outlined in my previous reply, these were some type of modified lens purchased here on the forum from another member long ago (I think that the fellow was in located in Texas). And, a dispute ensued because he swore to have purchased insurance for the parcel but never did despite confirming otherwise; I can only speculate that his reasoning entailed that the possibility of damage was unlikely. Unfortunately for me, he was wrong. Yet, I nonetheless ended up getting stuck with the accountability since the individual refused to assume responsibility.

[napos]

[innof]

Hi. Yes, I am certain that these are factory lens. As far as their scarcity is concerned, I have no idea.

I specifically recollect that the adaptors for these lens were a very early version and subsequently a better approach was perfected; Nonetheless, these seem to work quite fine as is.

What I am moreover curious about now is, will they serve to ameliorate my overall picture?

Thank you.

[gjaky]

I'd say the resolution of a 8500 is OK, and it should light up a 2.5m wide screen in dark conditions, the bigest set back is the poor contrast ratio of the air coupled lens system, although you can improve that as well somewhat with clever masking of the tubes.

[innof]

Okay, that is a very interesting revelation. How can I effectively mask the tubes? Can you please elaborate as to what this specifically involves.

Thank you!

[gjaky]

There is a light crosstalk between the tubes because there is a wide gap between the tubeface and the lens. So first, one should put black sheets between the tubes so it would effectively block the leaking light.
Second, the tube face also should be masked so only a slightly larger area is unmasked than the actual projected picture. The baest way would be do this right on the tube face, but that is less convenient of course.
These ideas are not my merit, you can find older threads dealing with these ideas..

[innof]

Very well then, I will look this up here on the forum.

So....... Is there indeed a consensus as to whether the projector can do 1080P?

And, I am still not too clear as to what role a scaler would play here; I wanted to connect a PS3 for viewing movies and have it accordingly determine the resolution.

[AnalogRocks]

[AnalogRocks]

[innof]

Thank you for the detailed reply regarding the scaler, I do appreciate it

I very quickly hooked it up this morning and did not see any black bars on the image.

Also, what does the "porch pixel" adjustemnts do?

I am assuming that I am obviously going to need a scaler with a HDMI input; Is this correct?

Please do advise.

[gjaky]

All movies are shot in 24fps. For smooth motion on the screen, multiple of this framerate is needed on the CRT 48Hz, 72Hz etc. Unfortunately the standard HDTV resolutions have either 30Hz interlaced or 60Hz progressive scan framerate, neither is multiple of the 24Hz. Of course many source can hand over the input framerate ie. the 24Hz, but that is too low to be usable on the CRT.
A scaler can solve this issue as it receives 24Hz source material and it can scale it on the output to 48, 72 or whatever Hz, so you retain smooth motions.

CRT projectors are bandwidth limited, and 1080P at 72Hz is quite demanding for any (and especially unmodified) CRT projector. So the scaler could help here as well, by making use of „active area scanning” (do a search here) with 21:9 movies. There is an other possibility that works best on 8” or smaller tubes, that is interlaced scanning. For example 1080i 96Hz is a multiple of the 24fps, and it has a very nice flicker free impression because of the highs framerate, yet it only has the same bandwidth as 1080P 48Hz, that is not a demanding resolution from electronics standpoint. The price you have to pay here is the possible presence of the scan lines.

As for resolutions the 8500’s sweetspot is around 1600x900 which is a non standard HD resolution and is also an odd number compared to the 1920x1080 so scaling to that resolution will introduce digital artifacts to some extent for sure. Then it is better to let the projector smooth out the resolution it can’t properly resolve, in this way your rely on some sort of analog scaling that is at least free from artifacts, providing of course you won’t hit the bandwidth limit of your projector.

Porch settings define how many timing pixels are sent out for synchronizing the picture. Those may need to be taylored to the projector’s specifications. The Marquee projectors are quite forgiving in this regard as they can properly display a wide variety of resolutions without the need of setting porches.