The 2nd Official Infocus 4805 Thread. - Page 3

I use the Infocus 10m DVI-M1 cable directly from the DCT6412 to the SP4805, bypassing my AV receiver. I use the DCT6412 SPDIF audio connected via my Yamaha AV receiver.

The SP4805 was calibrated but that simply resulted in factory default settings for everything except RGB Gains at 58 and RGB Offsets at 28.5 (Bob Williams numbers which set the 4805 to DVI video levels instead of PC levels). The Aspect Ratio is set to "Native".

The DCT6412 TV Type is 16:9, DVI/YPbPr is set to 1080i and 4:3 overide set to OFF.

I currently manually move the DVI cable from the STB to my Bravo DVD player (which is set to 852x480 pixel-map) till I find a new DVI switching AV receiver.

Hope this helps!

can someone explain a bit or point me to what we mean by pixel map? Thanks.

DVI (Digital Video Interface) output offers a digital video signal from DVD to display without any analog conversion. The benefit of a direct digital connection is a picture free from the video noise and artifacts that are the result of D/A conversion. For digital fixed pixel projectors and TVs such as plasma, LCD, DLP, DILA and LCoS, this direct digital signal path allows a capable DVD player to select a "1:1 Pixel Mapping" DVI output resolution that can exactly match that of the display's native resolution. SOUND & VISION magazine's technical editor, David Ranada, called the resultant DVD/DVI picture quality from a Bravo D1 when displayed on a fixed pixel display "Reference-quality."

The result is that the image on the DVD is exactly transfered, pixel for pixel, from the DVD player to an 852x480 resolution display with no alteration of any kind.

There are currently only three manufacturers that provide capable DVD players: V Inc. (Bravo), SnaZio and Momitsu. You can also use an HTPC with a DVI connector and proper software.

You cannot "1:1 pixel map" if using any connection other than DVI (HDMI) and you cannot do it unless the DVD player offers a pixel-map output. 480i, 480p, 720p and 1080i will not cut it!! Neither can you do it with a 576, 720 or 1080 display (well *maybe* 576 with a PAL DVD).

Thanks Ja Phule. I'm runnin vmr9 so I made the bob williams adjustments. Looks good.

Pixel mapping means that every 1 pixel on the display is being represented by 1 pixel from the source.

SO if you have a 854x480 native display and you are sending it a 854x480 feed then you have 1:1. This is also true for 848x480 as 3 pixels are being cropped from each side. YOu can only map to the 4805 over dvi as this is the only digital input on this device. But trust me, its worth it.

cavu/gushy, thanks for the explanation. So, how much better would the DVI actually be as opposed to the component input? i.e. what will happen if your send the source 480i signal via component instead of DVI?

Understand that simply using DVI (HDMI) does not get you "1:1 pixel mapping". You can also run interlaced and progressive signals across a DVI connection and whether that signal is better than the same type of signal across a component connection will be a function of the quality of the DVD player. But nothing is as accurate as a "1:1 pixel-mapped" DVI connection!!


First, understand that no connection via the M1 connector on the the SP4805 uses the Faroudja filter. So, specific to your question, a 480i signal will probably be handled best through the component connection.

No image visible when connecting SP4508 to Comcast dct-6200 using DVI port.
Comcast confirms that DVI port on the 6200 is active, they came out to my house and tried 3 different STB's, they all had the same issue. I tried a different DVI source( my laptop connected to it's docking station) using the DVI port and this working fine, I also tried another DVI source (LG lst-3510A HD Tuner/DVD) and this also works when using the DVI port. This confirms that my 25 ft DVI cable and M1 adapter is good. Anyone have any ideas what might be the issue here?
PJ is running the latest firmware.

Don't know. It's obviously not the projector. Post your query to the Official Comcast 6412 w/ iGuide Discussion forum.

Tradewinds,

THe reason that dvi is better is that there is no digital to analog conversion occuring. When you send a signal over component it is first converted from a digital signal to an analog signal as component is analog. THis conversion process can introduce artifacts. This is the main reason dvi is considered superior; you're taking a digital source, keeping it in digital format, and sending it to a digital display device. Thus there is no conversion occuring with dvi.

As Cavu says, merely using dvi does not guarantee 1:1. You have to make sure that your dvd player will output the native resolution of the 4805 which is 854x480. If you are thinking of upgrading your dvd player get one that Cavu listed as this will yield the best PQ for your dollar.

I use my computer, with a 6600gt video card, to send 848x480 to the projector via dvi. While 848x480 is not native the PJ crops the image taking 3 pixels off each side to display a 1:1 pixel mapping.

If you are using a component cable to send 480i to the pj then you will be taking advantage of the faroudja deinterlacer which is probably better then the deinterlacer in your dvd player. I cannot comment on the PQ of faroudja because I have always used a htpc but from what I've heard and read it is excellent.

I also use an old computer relagated to HTPC use - at 848x480 - love it.

-W

So does the new influx of refurbs mean another million views?

BTW our millionth viewer said after the holidays for his tune - time to get hold of me if you want to claim your prize!

I think on this thread I shall provide no meaningful info....and compete with Brian I Am for insiteful social commentary....

I got my refurb today looks to be in great shape. This is replacing an Epson s1. It looks much, much better than the espon. My living room is small and I am only using a 60" wide screen sitting 8 feet away but it looks fantastic. My epson did throw a bigger picture at the same projector distance, so I have to use full zoom on the infocus, but it looks great to me. I had it hooked 480p over component to a liteon lvd-2001 and was getting these weird pulsing waves. They did'nt go up and down like a ground loop, but staying in the same position and they were throughout the image. I switched the dvd player to 480i and they went away. I'll be using this with my computer but it only has a vga and component output .
What i s the recommended output resolution I should set? I can use 856x480 and 1280x720.

About how long did it take you folks to get your refurbs?

I ordered mine Friday, had it Tuesday.

Krasmuzik,

I look forward to your social commentary and your ability to correct us if we should give wrong advice. Us n00bs are still working out the kinks.

I think that would be a crime!

Correct EXCEPT you cannot run a 480i signal into the M1 -- it does not display correctly. I mention this not to be a weenie for details but because it drove me nuts for a while before someone here explained that the M1 can't handle 480i input.

Agreed.

And on a related note... As someone who has spent more time than I care to admit online at AVS in the 4805 thread(s) I'd like to comment on the supposed "noise" that allgedly pollutes our fair community.

If you want specs and interaction limited to strict technical 4805 talk, go read a FAQ or a manual or email tech support. Hanging around here is like hanging around in a virtual PJ shop with all the peripheral banter you would expect between the regulars. That's what makes it special. So if it takes you a few minutes longer to find the specific answer to your query when searching, count to ten and remind yourself that that is the price for participating in a living breathing community.

I think you are in denial!

BD801s was taking up too much space in the room, and was having a few too many technical issues... SO, I jumped on the SP4805 bandwagon. Looks like it might be a week or so before I get my refurb'd unit, but I imagine it'll be worth the wait.

On a serious note ... seriously ... this is very true.

I am actually shut in, recovering from a stroke. Providing what support I can here is actually therapy for me and provides me with a virtual social life in the process. (I know, I know. How very, very sad.)

Well, after watching one movie, I can say I jumped the gun a bit on saying the 4805 cured me of rainbows. I can still see them, but they are very much reduced. Easily tolerable, and far better than the X1. Beyond that, the 4805 puts out a gorgeous image, that much is clear. It is quieter than the X1 (IMHO), although the noise it puts out has a different quality that I find somewhat more noticeable than the X1. Perhaps in time I will learn to tune it out, like I had with the X1. SDE was never really a problem for me with the X1 and the case is the same with the 4805. However, I think I'll be tempted to go bigger with the 4805, which may introduce that problem. Right now I'm running a 90" image, we'll see if I can resist the temptation to go bigger. All in all, I'm extremely pleased. And after selling the X1, it cost me about $50 to upgrade. Can't beat that (except for those of you that made money on the deal ).

cavu: My best wishes for a speedy recovery.

I have a regular DVI-D cable ...I found some cheap adapters on Ebay ...are these as good as Infocus' more expensive adapter?

Everyone's here for different reasons and I take almost the complete opposite approach to yours. I feel this is AVScience for reason and would prefer to stick to the technical or science end of things. It's the bantering which I'd rather avoid (but often can't resist), as my primary reason for checking in is not for friendship but I do try my best to be friendly.

But really, regarding the 4805 there's not too much more that can be said that not already in the orginal thread a thousand times over. Perhaps there should be a restriction on new members not being able to post until they've tallied a set amount of time in the search area of the site. Now some more mindless banter, I'm not sure why but relegating the original thread to the archives kind of reminds me of "1984" for some reason.

Fair enough, but as the son of a sceintist I can assure you that scientists joke around too.

Question:

I picked up a refurb 4805 from a "deal of the day" type website 45 days ago. Everything was going great for awhile. Now it seems as though the projector has lost a good bit of it's brightness.

The bulb counter was at 0 when I received it (could've been reset obviously), now it's around 90 hours.

What are the chances that they put an older bulb in mine and it's reaching it reached half-life ? Since I'm within the first 90 days will this be covered under warranty (I got the 12 monther as well) ? Should I contact InFocus, who should I talk to ?

I agree but often it's so hard to tell and often get's mistaken for scientific fact.

Yeah call Infocus

It may not be "as good" but they will likely work. Before you dismiss them, froogle Infocus' part numbers - you will find them elsewhere cheaper than Infocus themselves.

I just did what I usually do for drilling stuff...

Put paper on back of PJ

Poke holes or mark off where holes are

Tape paper to thing I want to drill

Drill through paper

Remove paper

I did this on a steel mounting bracket that was originally made to hold up a tv, it worked a charm.