Again, where are you guys ending up with with gamma?

I've got a prototype board so I don't know if it is the same (should get a production board soon). But on my board, I do between 8 and 10 turns. I seems to have settled into about 8.5 or 9. Basically, I've got just a little in their so I can have the same shadow detail but lower my brightness by 2.



P.S. Anyone tried the Xbox360 at 1080p over component through this box? When I tried this it resulted in a lot of strange tearing (don't know if it's an xbox problem, the transcoder, or my Zenith 1200/Cine8 Onyx).

I've not had any problem with other 1080p sources through it, but I've not tried the XBox360.

Dave

I've got a prototype board so I don't know if it is the same (should get a production board soon). But on my board, I do between 8 and 10 turns. I seems to have settled into about 8.5 or 9. Basically, I've got just a little in their so I can have the same shadow detail but lower my brightness by 2.
Thanks Dave. Sounds like we're doing about the same...

Kal

Kal,

Are you using the Xbox component output or the VGA cable hooked up to the pass-through? There is something really weird going on with the Xbox 360. It seems to me that the sync is sticking too far into the video.

A few people have had succes in moving the jumper from JP5 to JP6 and if needed turn the H-WIDTH potmeter slightly counter clockwise to reduce the sync width a bit. That should clear up then tearing.


Kim

Hey Kim,

Yep - The Xbox360 (with it's zero porch settings) does some odd things. I figured that manually tuning the H-WIDTH may solve it but never got into it as it was a loaner from another forum member who was over for the night so we didn't get into it.

We tried 1080p both through component and VGA ... nothing at all came out over VGA, but again, we didn't look into it look much and I don't have the Xbox anymore.

What I saw over 1080i/60 component however was amazing. Wow. I really need to get into HD-DVD! :)

Kal

I'm having about the same result as Dave using one of Kim's production boards . Works just great with my Toshiba XA1
Tom

All,

The transcoders are shipped with the gamma just turned off, turning clockwise will immediately increase it. Kal you are right, the first 8 or so turns actually doesn't do anything, I will see in a next batch if I can dial in the control range a bit better.


Kim
Based on this quote, those of you running 8.5 to 10 turns are only turning up the gamma a VERY little bit.

I'm wondering how much of this has to do with the sources we are all using and the PJ's.

?

Correct - we are only using Gamma a little bit. Any more (IMHO for my sources) tends to wash out the picture.

Kal

Based on this quote, those of you running 8.5 to 10 turns are only turning up the gamma a VERY little bit.

I've not seen the curve, but that is over 1/3 of the way to maximum (and maximum is WAAAAAAAY to0 high).

Kim, how many turns equates to Scott's original design for his gamma circuit?

Dave

Dave,

The maximum setting is slightly less agressive than Scott's original.


Kim

tse's curve ...

Dave,

The maximum setting is slightly less agressive than Scott's original.


Kim

Whoa, really?!?!? :eek: :eek: :eek: Max on yours is washed out. His was even more? I've not been able to even get something like 15 or so turns to not look washed out and flat.

Dave

A (simulated) comparison plot between Scott's original (in red) and the RTC2200 (in green) at maximum setting.


Kim

I've not seen the curve, but that is over 1/3 of the way to maximum (and maximum is WAAAAAAAY to0 high).

Kim, how many turns equates to Scott's original design for his gamma circuit?

Dave

Dave,

I'm not following you. Beun says the first 8 turns do nothing. You say that is 1/3 of the way to max.

?

A (simulated) comparison plot between Scott's original (in red) and the RTC2200 (in green) at maximum setting.Hm. That looks to me like Scott's circuit had a significantly lower level (-150mV??) at 0 IRE, but then it very quickly matches Kim's curve.

Would that indicate that blacks are blacker with Scott's circuit? At least blacker than Kim's when set to max?

Kim, does the 0 IRE level on your circuit change when you lower the gamma setting?

Gary,

Just looking at the IRE settings is probably unfair since it doesn't say much in the end. The projector will clamp black and with the contrast and brightness (actually black and peak white) settings on your projector you will dial in the two end points of the curve. When I do this in the plot it will look like this, again Scott's in red and the RTC2200 in green. As you can see Scott's is a litle more agressive around 30IRE but catches up at higher brightness.

Kim

OK, I didn't quite follow your explanation why, but I believe you. :) So it looks like Scott's circuit is MORE aggressive than yours at full blast? And most people are running yours with very very low settings, because anything higher is too washed out? Makes me wonder why people loved Scott's original circuit so much!

The reason probably is that Scott's original circuit has a much lower peak white and therefore looks darker, when using the RTC2200 you really would need to turn the white level (contrast).

Hm. That looks to me like Scott's circuit had a significantly lower level (-150mV??) at 0 IRE, but then it very quickly matches Kim's curve.

Would that indicate that blacks are blacker with Scott's circuit? At least blacker than Kim's when set to max?Edit. I'm too slow. :)

Blanking voltage level at this point doesn't mean how black black is going to be. Your projector need to take black reference from video signal back porch anyway, because input board coupling caps are making signal to floating (ac) after gamma box...

Finally you make decision which point from that gamma curve is going to be "black level" point in your screen, using brightness adjustment of your projector.

Even small differences in gamma box output (Vpp) doesn't mean much, because that is adjusted by projector contrast adjustment.

Only thing that matter at this point is shape of the curve, imaging that curves start and end from same points makes comparing easyer.

Another curve for comparison ...

Let's just say hypothetically that while adjusting in the dark and looking at the screen the picture disappeared instead of getting brighter at the low end, and then you looked around he back of the unit and saw your little screwdriver sticking out of the h-width hole instead of the Gamma adjustment hole.
How would one go about setting the H-Width (or any other of the pots for that matter) back to their default settings?

Just like hypothetically and all....

In that hypothetical case you would hypothetically do the following:

Leave BLK LVL alone
Turn H-DELAY all the way counter clockwise
TURN H-WIDTH all the way counter clockwise and than about 4-6 turns clockwise till the picture looks good
Leave V-WIDTH alone

This is purely hypothetical of cause.


Kim

Kim,

Though if you have all the jumpers set to their defaults, none of the other pots do anything right? So there isn't really any need to worry about how the other pots (other than BLK LVL [Gamma]) are set right?

Kal

Kal,

On the RTC2000 that is true, for the RTC2200 because of 1080p Xbox 360 compatibility the H-WIDTH and H_DELAY positions the internal black level clamp and therefore they are important. There is a fair amount of wiggle room so accidently turning them a bit won't do anything.

I will fix this 1080p Xbox compatibility in a better way in the next batch.

I will fix this 1080p Xbox compatibility in a better way in the next batch.Careful what you say here Kim - you may be opening up a can of worms with people wanting to exchange their current RTC2200's! :)

(Or is the fix simple enough that you think someone could do it themselves if they're comfortable with SMD soldering? That's a pretty small % of people though).

Kal

Kal,

The current RTC2200 works perfectly with the Xbox 360 and 1080p, it is just for convenience and to avoid any questions that the next batch will have the internal clamp decoupled from the H-WIDTH and H-DELAY.


Kim

In that hypothetical case you would hypothetically do the following:

Leave BLK LVL alone
Turn H-DELAY all the way counter clockwise
TURN H-WIDTH all the way counter clockwise and than about 4-6 turns clockwise till the picture looks good
Leave V-WIDTH alone

This is purely hypothetical of cause.


Kim

I'll give that a try as a thought experiment and see what happens.

Hi again Kim,

I am really interested in your transcoder.

I have to ask you one more time if you are going to be making a RTC2200 with adjustable gamma card for the NEC ISS switcher soon or at all? I just don't want to miss out on your transcoder and I will order the external box version if need be.

Thanks much!
Brad

I've been setting up a new 8500 so I didn't get a chance to check out my RTC2200 until tonight.

I figured rather than using the "crank it until it looks about right" approach, why not apply some SCIENCE? (She blinded me, with... no wait, nevermind)

I have a colorimeter, and a spreadsheet that calculates gamma &etc. I had just measured the 8500's grayscale (it sucked), and I decided to fake up some "perfect" values as a comparison. If we assume the x and y values are perfect (0.313 / 0.329), then what are the desired luminance values (Y) if we want IRE 100 to be 12 ftL?

Here are my measured luminance numbers vs. the "perfect" numbers computed for a 2.22 gamma:IRE 8500 Perfect
0 n/a 0.0
10 n/a 0.15
20 n/a 0.5
30 0.1 1.0
40 0.6 1.7
50 1.3 2.8
60 2.5 4.0
70 4.1 5.7
80 6.2 7.5
90 8.9 9.6
100 12.1 12.0(See attached pic for a chart of the 8500's numbers.) You can see why I wanted low-IRE boost so badly. The calculated gamma was almost 3.5 instead of the desired 2.22. My 10 - 20 IREs were so low the colorimeter couldn't measure them. Dark areas are TOO dark -- the perennial complaint of the CRTer. My XG was the same way. I always ran the brightness too high (no "fade to black" possible) so I didn't crush the blacks too terribly, and of course that washed out the picture.

So! Now we know what the values SHOULD be, let's plug in the RTC2200 and fix it!

I displayed an IRE 30 window in Avia, which "should" be 1.0 ftL. I fit a screwdriver in the @#@#$ little setscrew and started turning, and turning, and turning... it got up as high as 0.8 ftL and stopped. The screw kept turning, but I got no more boost. I couldn't get it up where it "should" be.

Furthermore when I checked IRE 100, it was at 17.5 ftL !!! Eeeyowch!

If I plug IRE30 / 0.8 and IRE100 / 17.5 into my colorimeter spreadsheet, the resulting curve doesn't look THAT much better than than the unmodified curve. The computed gamma has dropped a bit, but the low IREs are still much too low compared to the IRE100 level. If I scale IRE100 back down to 12.0, that puts IRE30 at about 0.5 -- better than it was, certainly, but not where it's "supposed" to be.

So:
* Should the Kimcoder be able to boost low IREs enough to get "correct" 2.22 gamma?

* Am I going at this wrong, and the "perfect" values I calculated are all wrong? I believe the spreadsheet is right.

* Why is it boosting my IRE100 levels by 50%!? I thought it was supposed to do all its boosting at low IREs, and the boost tapered off to zero at higher IREs. I haven't thrown an oscope on the video signal yet, but if the previous video signal had proper 0.7V p-p for IRE100, then the cranked output of the Kimcoder must have been 50% over that!??

* Should there be "detents" or "stops" at the CW and CCW extremes of the BLK LVL pot? I can turn it, and turn, and turn, and the only way I can tell I've gotten to "max" is that the brightness stops increasing. The pot never stops turning.

Gary

EDIT: attachment changed to target 2.5 gamma instead of 2.22.

Gary says, "My 10 - 20 IREs were so low the colorimeter couldn't measure them."

Get a magnefying lens and position it to focus the projected light on the sensor. That will let you measure much lower light levels. The bigger the lens diameter the lower you can measure.

Scott

Humble suggestions..

* Aim for gamma ~2.5, which is the "natural" gamma for CRT. 2.22 in a dark room will look very flat..

* Download Color HCFR (http://www.avsforum.com/avs-vb/showthread.php?t=737550). Great (free) measurement app.

17.5fL?!? What screen size are you using?

// Lyckman

Brad,

I am finalizing the ISS version, the only thing left is to put the electronics in for audio switching although I haven't figured out yet how to put 2 RCA's on the front panel. The first few test boards should go out by the end of the week.

Gary,

One of the side effects of increasing gamma on the RTC2200 is that peak white will increase. The linear effect is not that great, it goes up from 700mV to around 850mV (there is a simulated plot showing this effect in the manual), with the CRT gamma the amount of fL will probably rise a bit more.

Unfortunately the potmeters have no obvious stop, I will look around if I can find others so you can at least feel it.

Kim, NEC made an HDTV input for the switcher and they ended up sing 2 slots versus one... Maybe this would help?

Let me know when I can order one or help with a test unit. I'd recomend sending one to Dave, but he doesn't have a switcher... alas.

Thanks,

Marshall

Audio switching? I thought these were for video only?

Brad,

Yes, they are video but someone else mentioned it would be nice when it would at least switch 2 channel audio as well, it is an relatively easy addition.

Get a magnefying lens and position it to focus the projected light on the sensor. That will let you measure much lower light levels. The bigger the lens diameter the lower you can measure.Interesting idea! I figured I could just move the sensor closer to the projector, but this would work without having to change the setup for low IREs. But don't you get into trouble with chromatic abberations in the lens unless you're really careful? And of course your luminance readings are wrong.

If I boost the low end to proper gamma, I'll have less trouble reading the low IREs. I should be able to read 20 IRE without any tricks.

Humble suggestions..
* Aim for gamma ~2.5, which is the "natural" gamma for CRT. 2.22 in a dark room will look very flat..
* Download Color HCFR (http://www.avsforum.com/avs-vb/showthread.php?t=737550). Great (free) measurement app.OK, gamma = 2.5 is easier to hit. With that gamma and IRE 100 = 12 ftL, IRE 30 "should be" about 0.7 ftL. But I don't think the RTC2200 can hit that when I back the contrast down to get 12 ftL at IRE 100. I think I'll be limited to about 0.5 ftL at IRE 30 with 12 ftL at IRE 100.

Yes, I plan to get HCFR one of these days, but I'll have to get/build a sensor first. In the meantime I have a colorimeter that works. :)
17.5fL?!? What screen size are you using?85" wide! It was only a window pattern, not a full screen, but it was probably still at least 3' square. Which would say that small piece of the CRT faces was delivering 17.5 ftL * 9 ft^2 = 157.5 lumens? And the whole 4:3 tube face is only rated for about 240 ANSI lumens!

I was shocked when I saw how bright the 100IRE was. :eek: I didn't leave it on for very long! Didn't think to check if it was driving the 8500 into blooming, which definitely happens if you turn up the contrast that high, but I assume it did.

One of the side effects of increasing gamma on the RTC2200 is that peak white will increase. The linear effect is not that great, it goes up from 700mV to around 850mV (there is a simulated plot showing this effect in the manual), with the CRT gamma the amount of fL will probably rise a bit more.OK, I missed that in the manual, and misread the charts -- because both peaked at 0.7V. I should have looked at the p-p values. So I just back off the contrast until my 100 IRE hits 12 ftL? There's no concern with overdriving the projector's video input circuitry with that "hot" signal?

EDIT: It just occurred to me, I'm currently running the signal from the RTC into an Extron 202rxi. I could back off on gain with the Extron so the projector still sees a 0.7V signal. Seems like that's gotta be better than overdriving the inputs, even if it means an extra box in the signal path?

Gary

Kim - any interest in making a component OUTPUT for the NEC ISS Switcher? Just thinking outloud, but it seems like it could be an easy way to add a second display output to the switcher (e.g. standard BNC to the PJ, component to the TV in a nearby room). Not sure how big the demand is or if existing splitters or switchers are the better way to do that. . .

Kim - any interest in making a component OUTPUT for the NEC ISS Switcher? Just thinking outloud, but it seems like it could be an easy way to add a second display output to the switcher (e.g. standard BNC to the PJ, component to the TV in a nearby room). Not sure how big the demand is or if existing splitters or switchers are the better way to do that. . .
I would think that using a separate splitter or switcher would make more sense since (IMHO) few people would need this.

Makes more sense (again IMHO) to have 1 person in 20 buy a splitter and use it than have all 20 pay for splitter functionality that only 1 person in the end uses.

Of course it makes sense to double or triple up functions that you know people are mostly all going to use (like gamma for example - no point in having a transcoder box and a separate gamma box after).

Kal

Gary,
Sometimes science needs to be looked at through eyeballs. Doug

No argument, Doug. :) We need to set this thing to what looks good to us. But I figured if I knew what the luminance values "SHOULD" be, it would useful/interesting to set it there and see what it looked like. Maybe that "ideal" 2.5 gamma looks like crap. But I figure there's only one way to find out.

So I got a chance to play with this a bit more. I cranked the RTC to max, backed off on the contrast to bring IRE 100 to 12.0 ftL, set the brightness according to Avia, and checked my numbers. I didn't touch anything else, so e.g. the color-temp adjustments are unchanged, just as bad as they were before. See attached chart, and compare it to my previous post.

It's definitely much better than it was. The R and G are almost dead on. (Black dotted line = ideal 2.5 gamma.) Still a bit low at low IREs; my colorimeter can't read 10 IRE so it must be < 0.05, where it "should" be 0.1. I may be able to tweak that with the G2 settings, but maybe not without messing up my color temps.

The blue is still way high in the midranges. I believe this is caused by having the contrast high enough that the blue overdrives and starts to flatten out. Then if you set the color temp at a high IRE, you're setting it in a non-linear range, so it overshoots the proper midrange levels in order to hit the desired high-IRE level. I think. So I need to lower my contrast if I want the color temps to be right across the IRE range? (Any expert opinions on that?) If I color-filter the R & G, that will cut down on their output, which might bring them closer to what the blue is capable of. But in any event it looks like 12 ftL on an 85" screen is too many lumens for this projector to pump out.

I do definitely see much more shadow detail than I did. I haven't watched enough to be sure but I don't think it has that eye-straining "too bright" look that it has when the dark areas are too dark.

At first glance it looks like the colors are really dead. I looked at the Peony Pavillion scene from House of Flying Daggers -- a great color scene -- and it looked flat and washed out, almost monochrome. This may be due to the color temp being off? It's between 7000-8000K in the 40-80 IRE range. So it may be more noticeable due to the gamma change but I doubt it's *caused* by the RTC.

I saw some vertical lines at the edges of the raster. This projector is still new to me so I'm not sure, but I don't *think* those were there before.

Bigger concern: I had a LOT of video noise in the signal, especially in strong red areas. Horizontal lines across the area, always moving, where the red "drops out." With my XG that happened if you drove it with too hot an input signal. I strongly suspect the same thing is happening now with the 0.8V p-p input. Isn't anybody else seeing this? Maybe nobody else is cranking it to max? Even though that's what it takes to produce something close to a "correct" gamma curve?

I imagine I can resolve that by backing off the RTC settings. (Kim, would you expect any more noise in the circuit at the max setting?) But the low levels are already a bit lower than they "should" be, and reducing the RTC settings would make that worse. Another option is to use my Extron box to tone down the video to a 0.7V p-p range. I'll experiment with that when I get a chance.

What's the current lead time for a gamma capable box? I'm finally ready to get my 9PG+ going and I don't have a transcoder of any kind to work with.

Dave,

Yes I can make a ISS output board that does the transcoding, if it makes the same or more sense than an input board. The layout is finished I just want to do a final check before I have a few manufactured.


Gary,

I don't think the video noise gets worse when you crank up the RTC2200, the increase in gain at the low levels is not that much. In any case there should only be more noise in the dark areas since the circuit is active there, above 50IRE it essentially does nothing.

Dropzone,

When you order today or tomorrow I can ship one on Monday.


Kim

Would work great in my application, but if there is a lot of cost going into a different design I can track down another approach, like Kal said.

OK, if the noise isn't coming from the tcoder, then it must be from overdriving the inputs. I'll turn down the Extron to lower the input voltage.

Gary,

There is a blue gamma circuit on the VIM bd. It's curve boosts higher level video so as to correct the drop-off in blue output at higher outputs. Your curve shows that. Check my sketch. The blue output still drops off beyound a certain point.

Scott

Brad,

I am finalizing the ISS version, the only thing left is to put the electronics in for audio switching although I haven't figured out yet how to put 2 RCA's on the front panel. The first few test boards should go out by the end of the week.



Will this only include component and vga connections? or will it include an hdmi similar to moome's? I would think an HDMI would make sense to not directly compete with the 2200, your own great product, but both would be nice.

If you are sending units out for testing does that mean a production versions within the next 6 months??

tse -- hm, OK, but as you can see by the chart it wasn't enough to do the job without defocusing the blue. I defocused the blue (center position of blue RGB focus) from 48 to 58 and did a few other things and it's looking much better now. More details in this post (http://www.curtpalme.com/forum/viewtopic.php?p=42004).

Gary

OK, if the noise isn't coming from the tcoder, then it must be from overdriving the inputs. I'll turn down the Extron to lower the input voltage.

I used to use Extron craponents, but was astonished to see that when I switched to ALTINEX, my signals were much, much, much cleaner...(I can't stress that enough, MUCH cleaner, night and day, stand right out like a big sore thumb cleaner...)
I never saw it till it wasn't there, but the Extron crap used to add terrible high frequency noise to the image.

If you're using an Extron craponent to boost your signal you're really degrading the image... I just hope you're not doubling that degradation by using an Extron switcher too ??

Greg,

The ISS version will only have component on BNC's since the connector space is limited, I don't even think I have room for an additional VGA connector.

HDMI is in the planning but getting good information on the various IC options and how to hook it up seems to be limited, I am groping a bit in the dark here.


Kim

I am finalizing the ISS version, the only thing left is to put the electronics in for audio switching although I haven't figured out yet how to put 2 RCA's on the front panel. The first few test boards should go out by the end of the week.



If the original ISS RGB inputs have 5 BNC Connectors as well as 2 RCA jacks for audio, it would seem that you would use the same configuration on the back panel minus 2 BNC positions :confused:


Unfortunately the potmeters have no obvious stop, I will look around if I can find others so you can at least feel it.

That would be a great improvement. I have now purchased 3 sets of small screwdrivers trying to find the ones that work best - and I have yet to find a perfect one.

The Stanley 6 Piece Screwdriver set (1.4mm - 3.0mm) available at Home Depot for $5.97 (HD Sku number 076174660395)(Stanley Number 66-039) seem to be the best option I have found thus far, but the lack of hard stops is frustrating.

If you're using an Extron craponent to boost your signal you're really degrading the image... I just hope you're not doubling that degradation by using an Extron switcher too ??No, no switcher. I'd really prefer not to use the Extron -- and I DO see some hi-freq noise in the signal, just haven't nailed down where it's coming from yet.

But the RTC2200 really boosts the signal level when you boost the gamma, and that was overdriving the 8500's video inputs. If I wanted to turn up the gamma, I had to turn down the video signal level, and that's what the Extron is doing.

Kim, any chance of a future rev that sticks to 0.7V p-p??

Kim,

Never noticed this before but when I pass 1080i/60 thru the RTC-2200, I get a thin vertical line about 10% of the way in from the left edge. It runs from the top to the bottom of the raster.

Happens on my HD-PVR (Expressvu 9200/Dish 942), a two HD-DVD players: A Toshiba HD-A1, and a Toshiba HD-A2. All running at 1080i/60.

I swapped out the RTC-2200 for a really old (circa 2004, v2) test version of your transcoder and the problem is gone so I know it's the transcoder adding the line...

Any thoughts?

Kal

Seems a bit odd for this to happen in pass thru mode . What happens if you reduce the gamma control to minimum ?

Kal,

Since you are using a HD-A1 I guess it is in transcoder mode, like dominical suggested can you try if the line depends on gamma but also if the relative position of the line depends on either H_DELAY or H_WIDTH. Also, is the line white or black? Can you also verify if the line is there at different resolutions (480p, 720p) as well?

I will try if I can see this in my test setup as well.


Kim

Thanks guys - I'll do some tests tonight with your suggestions. Not sure if it happens in VGA passthru mode. I've only tested 1080i/60 thru component so far. The line is "whiteish": Most of the content's in the blue tube. It's pretty dim - you only really notice it onscreen in 100% black screens but it's really obvious if you look in the blue tube with reasonably dark scene.

Kal

Kal,

I just put one of the transcoders on a scope with a black input signal and I cannot find anything in the active video that shouldn't be there I have tried it with and without gamma and I varied the H- and V-WIDTH as well. Shall I just send you a new one?


Kim

I seem to have the same thing happening as Kal. There appears to be a white line on the left side of the raster looking into the blue tube. And sometimes you can just make it out on the screen in dark scenes. Adjusting the H-Delay pot did minimize it some but its always there for me. 1080/60i thru component as well.
Jamie

If this is what I saw here:

http://www.curtpalme.com/forum/viewtopic.php?t=529&highlight=white+line+right+side+screen

Its a oddity thats been around for awhile on 1080I. Doug

Jamieh: Yep - that's it. It's a dim white line in the blue tube about 5-10% from the left edge. On the red tube it's a black line. On green you barely see a black line.

I was able to get rid of it by playing with the H_DELAY and H_WIDTH pots. Both turned all the way CCW first, then 3-4 turns at a time. IIRC, it went away with both turned approx 5-6 turns from all the way CCW. (The rest of the image didn't change at all).

I still do see a little bit of the line and some ringing on the left side of the image but nothing major and it doesn't show up on the screen so I'm happy. I'll take a picture of it tonight and document a bit better how to make the line appear. Not worth sending me a new transcoder Kim... I mean, actually, err.. yeah.... I could use *another* transcoder so if you want to send me a new replacement board I wouldn't say no... I'll dispose of this one here as it's obviously defective. :) :D :D

Kal

That may be the same vertical line I was seeing on the left side of my screen, but I'm pretty sure I saw it on 720p, not 1080i. I'll try to take a look soon and see if the H_DELAY / H_WIDTH pots help it. I can't quite tell from the manual without opening the box -- did you have to change JP5 / JP6 to modify H_DELAY / H_WIDTH ?

Turning the H-WIDTH and H_DELAY without moving JP5/JP6 will only change the width and position of the internal clamping pulse, when you move JP5 to JP6 the H-sync output will also be effected.


Kim

Another data point: I've got the same line, and this is on 720p for me, since I don't have any 1080i sources at present. I'll try Kal's fix. - Pat

I still do see a little bit of the line and some ringing on the left side of the image but nothing major and it doesn't show up on the screen so I'm happy. I'll take a picture of it tonight...Sorry guys, but the pics aren't working out at all. You just can't see the details (difficult to shoot through the lens and C-element. If I took the lens and c-element off then it would work. Taking the lens off is easy, the c-element however is a whole other story).

Kal

I still haven't sent the old board back yet, so if Kim would like me to send the new board, as currently installed and showing the line, perhaps this would be the best way to diagnose the problem and determine the cause and best cure. Just let me know guys, and I'll get the board shipped. - Pat

Pat,

I can send you a new one with return shipment label so you can send the old one back and I can have a look at it. Shoot me an email.


Kim

Great, Kim - PM sent. - Pat

Im not sure this oddity is specific to Kims, I have seen it on other transcoders also. The previous post was using Petr's. I just came back from installing HD via Kimcoder in a previous HTPC DVD 720P only install and seen the same thing again. The same video card was changed once and had a dif phase setting. On this one I moved the mechanical raster / phase a bit to have better use of 1080I 'width', once done it wasnt there.

I wish all source devices had some sort of 'standard' that was actually followed but I notice you can have the same model of STB or HDSTB and have two different phases in each. Not just a STB deal I have seen DVD players do the same. Stick all these 'sources' together on one set up and you will get some oddities to work through. That and we change sources alot and push 'levels' around. Doug

After allready spending a small fortune trying different transcoders, I wish there was just a cheap gamma correction only device for component or VGA passthrough. I think there would be quite a large market for something like this.

Kim, have you ever given any such device any thought?

The gamma circuit would be around $200 so I guess Kim throws in the transcoder for free then adds a free passthough then adds adjustable just because. Doug

The ISS card test boards shipped, I need to get some other parts and can start building the firsat boards soon.


Kim

:)

After allready spending a small fortune trying different transcoders, I wish there was just a cheap gamma correction only device for component or VGA passthrough. I think there would be quite a large market for something like this.

Kim, have you ever given any such device any thought?

You should have just bought Kim's new transcoder w/gamma correction in the first place . :D :D :D
Tom.W

Chad, it may be of interest to others of what not to buy -- would you list the XCoders you have been unhappy with? I think Dave here has been through quite a few and he is very happy with Kim's transcoder. Offhand, the only other one I would recommend is Moome's and that is if you need HDMI - otherwise Kim's is the one.

Thanks, Kim - would you let us know when & how you will be taking orders for ISS version?

The ISS card test boards shipped, I need to get some other parts and can start building the firsat boards soon.


Kim

I can't wait, please let me know the INSTANT I can order one! :D

Brad

After allready spending a small fortune trying different transcoders, I wish there was just a cheap gamma correction only device for component or VGA passthrough. I think there would be quite a large market for something like this.

Kim, have you ever given any such device any thought?

What do you call cheap? You can do this with Kim's gamma tcoder.

Dave

After allready spending a small fortune trying different transcoders, I wish there was just a cheap gamma correction only device for component or VGA passthrough. I think there would be quite a large market for something like this.

Kim, have you ever given any such device any thought?

Do you mean one that looks like this?:


http://www.crescendo-systems.com/images/RTC2000_rear_small.jpg

GE, that was classic! LOL

So, Chad, what do you think Kim makes?

Guys...be nice. ;) I need to order one of these soon. I will be hauling my 9PG+ up the stairs this weekend to start setting it up. The last transcoder I had was a VDIGI that Clarence so graciously let me borrow. I expect this Crescendo unit will be much better.

The last transcoder I had was a VDIGI that Clarence so graciously let me borrow. I expect this Crescendo unit will be much better.

Wow, if that is what you've been using, you will be VERY pleased.

Dave

Wow, if that is what you've been using, you will be VERY pleased.

Dave

Yeah, it was a quick fix for the time being and Clarence himself gave me the disclaimer regarding picture quality so I never had any great expectations regarding the VDIGI.

GE, that was classic! LOL

So, Chad, what do you think Kim makes?

I was talking about a component or VGA pass-through only device with the sole purpose of adjusting gamma - no transcoder included.

I know Kim makes a transcoder with gamma adjustment.

Scotts' (Tse's) original design is just what you are describing, but it's a DIY kind of thing.

Hi Kim,

How are things going with you & Xcoder for the ISS?

Thanks,

Marshall

Hi Kim,

How are things going with you & Xcoder for the ISS?

Thanks,

Marshall

Perhaps he came to his senses. ;)

I am afraid I haven't come to my senses, I finished a preliminary version and send it out so it could be looked at. In the meantime I have redone the layout and am waiting on the results of the evaluation before having the new boards manufactured.


Kim

Hi Kim,

How are things going with you & Xcoder for the ISS?

Thanks,

Marshall

I have one of his demo boards - as well as his external unit and about every other type of Xcoder one can come up with (including Moomes, Analog Way, NEC and all the rest).

Nothing works as well and as accurately as Kim's card - and no black crush as in the other pick of the week card :D

I have one of his demo boards - as well as his external unit and about every other type of Xcoder one can come up with (including Moomes, Analog Way, NEC and all the rest).

Nothing works as well and as accurately as Kim's card - and no black crush as in the other pick of the week card :D

Waiting very patiently for the ISS card. Any updates on progress? :)

Waiting very patiently for the ISS card. Any updates on progress? :)

Kim, here's a thought (I'm NOT inviting this thread to become a bash-a-thon of this or any other solution...)
Would an ISS be forthcoming, how difficult would it be to make it readily modifiable? That is, can you expose (without introducing a source of interference) any pads for mini-coax ahead (or behind, or both) of the gamma circuit? This way a digital-to-RGBHV Xcoder daughter-board could be introduced (a'la JohnHWman's DHI/HDMI miniboxes?) so we can get best-of-both-worlds performance.

I was actually waiting on some more response of people interested in this card. I have finished the design and board layout but haven't sent it out for manufacturing yet.

I will see it there could be a possibility to have some sort of a secont input. Would a jumper block like the Moome solution be appropriate?


Kim

OK, I'm going to ask a stupid question, why do you guys want an ISS card? Why hamper Kim's card with the ISS output stage?

If you need to switch component, you do it before the tcoder. If you need to switch RGB and component, his can do that. If that is not enought, why not buy the existing one and run the output to an ISS RGB card if you think the ISS is good? That way, you could just directly plug the JohnHWman designed HDFury into the RGB in and get exactly what jtnfoley wants.

Dave

Jumper block would be alright if the mod was structured. I'm more interested in nice round pads and thru-holes so any little hack can work.
I'm thinking, take the new $130USD retail HDMI/VGA device from JohnHW being made in volume by someone, crack it open and remove the HD15M connector, and pick up RGBHV with mini-coax. Some adhesive standoffs and zipties and wa'la! Instant hybrid HDMI input for the RTC2200ISS.
Obviously, there would need to be backplate real estate for an HDMI connector to poke thru.

If that is not enought, why not buy the existing one and run the output to an ISS RGB card if you think the ISS is good? That way, you could just directly plug the JohnHWman designed HDFury into the RGB in and get exactly what jtnfoley wants.

Dave

I'm thinking the lack of 75ohm may cause artifacting in some of the better displays, and Fury->RTC2200->ISS would be a cleaner, cheaper (some would argue better) path to gamma corrected HDMI than other solutions currently available.

I'm thinking the lack of 75ohm may cause artifacting in some of the better displays, and Fury->RTC2200->ISS would be a cleaner, cheaper (some would argue better) path to gamma corrected HDMI than other solutions currently available.

No one has complained about that with Kim's and in fact tse's tests showed his box pretty damn good. Kim is a pretty good EE and said that it is not problem.

Further, the difference in resistance of connectors matters more as distance increases. So, if you use a short VGA to BNC breakout, you won't be able to tell the difference between than and BNC connectors. Heck, one of the enthusiast sites (I'll have to search for it--Pete posted a link to the article at Curt's) compared cables with 50 Ohm connectors to cables with 75 Ohm connectors and over long runs there was pretty much no difference on the test equipment, let alone what you can see.

Further, another good EE has looked at the ISS and Kim's and said the output stage of the ISS is not great. So, summing up all this info from guys that are more knowledgable than me and have actually tested this, Kim's with a short VGA to F BNC would be a better solution that an ISS card.

The only thing you would gain from the ISS is dual monitor output. If you need that (like I do) then the real question is which is worse on the signal, a 1x2 VGA or RGBHV box or the ISS. I've got no data or tests on that, but I can say there are 1x2 boxes with more bandwidth than any ISS so??? :)


Dave

I'm thinking the lack of 75ohm may cause artifacting in some of the better displays, and Fury->RTC2200->ISS would be a cleaner, cheaper (some would argue better) path to gamma corrected HDMI than other solutions currently available.

BTW better why? Because of Kim's/John's vs. Moome's or the ISS? If ISS, I don't agree.

BTW better why? Because of Kim's/John's vs. Moome's or the ISS? If ISS, I don't agree.

A funny thing happened on the way to the Phorum... A back story that you may not be privy to, and that I will not share.
Suffice it to say, some would argue that there are lesser solutions to HDMI/HDCP available. I'm just interested in making a viable multi-input component/HDMI transcoder that is cost effective, easily controllable, and PJ independent (as I'm in the middle of the upgrade cycle, with an 8" low-intermediate projector in my HT. Hedging against obsolescence is I'll I'm petitioning for...)

OK, I'm going to ask a stupid question, why do you guys want an ISS card? Why hamper Kim's card with the ISS output stage?

If you need to switch component, you do it before the tcoder. If you need to switch RGB and component, his can do that. If that is not enought, why not buy the existing one and run the output to an ISS RGB card if you think the ISS is good? That way, you could just directly plug the JohnHWman designed HDFury into the RGB in and get exactly what jtnfoley wants.

Dave

I thought the ISS switchers were transparent? Is it possible that the ISS that was tested was faulty in some way by having bad capacitors or something else wrong? Considering the age of units and hours upon hours of usage they all have something could have failed. I know I had problems with my ISS, but I was lucky and scored a brand new RGB output module and my problems went away completely. Regardless, I think I might go ahead and order Kim's external box if no ISS card is going to be made.

B

When there is a reasonable demand for the ISS card I will produce and I will look into a bypass mode. regarding the back-plate real-estate I am not quite sure, although you don't really need much.


Kim

What is the current lead time for a reverse transcoder with gamma? The site shows "out of stock". I assume they are all made to order. I have done without for too long and I'm finally ready to buy.

I think I ran out of cases but I am not sure since I am abroad at the moment. I will know more this Monday. When I am indeed out of cases it will take about 4 weeks to get new ones in.


Kim

Psssssh, who needs a case? :p.

Looking forward to an update...

So, how long is the wait for a unit with gamma at this point? I guess you had to order cases?

The cases are on order and will take about 4 weeks.


Kim

What is that adapter? How does this setup compare to a VisionFC4? Does it ignore HDCP?

I tried a 1080p component signal from a trailer played on a PS3, the RTC2200 couldn't keep up and dropped the signal. How does a 1080p DVI signal compare?

I tried a 1080p component signal from a trailer played on a PS3, the RTC2200 couldn't keep up and dropped the signal.

I've never had a problem with the RTC2200 when tested at 1080p and I've never heard any other problems. My guess is it was the PS3 at fault. It wouldn't be the first problem device from Sony. :rolleyes:

JD213,

There are a few instances depending on the version of the RTC2x00 where you may have to change a jumper inside to get the correct handling of 1080p/60 signals. Just shoot me an email to klbeumer@crescendo-systems.com and I will be able to help you further.


Kim

Thanks. There's not much 1080p content available over component so no hurry in getting back to me.

I finally ordered one of these and hope to have it soon. I'm anxious to see how this compares to my Key Digital transcoder. Hopefully the gamma boost option will help with some of the black crush I am seeing right now.

Well, after some screaming at Fed Ex after they delayed my delivery and put the box on the wrong truck, I finally received the transcoder last night. Kim shipped this very quickly and if not for the Fed Ex screw up I would have had it Friday and had the weekend to play with it. So, of course after receiving it last night I could not just let it sit there. First of all let me just say that I am no videophile and the best tool I have at my disposal are my own two eyes. With that being said, here are my initial impressions of the RTC2200 unit with gamma correction. Right away I was surprised at the size of the unit. I guess I was expecting something about the size of my Key Digital unit but this thing was about three times that big! I'm not complaining, I think that's a good thing as it probably has more goodies packed inside than lesser units. It looks more like an actual component that can go on the stack rather than just a matchbox connected between cables. The case was simple but well put together and sturdy. So, I disconnected my Key Digital unit and hooked up the Crescendo transcoder. I have some HD video saved on my HD DVR that I view regularly to make comparisons when I change settings and what not. The difference was not immediately noticeable but keep in mind that at this point I have not touched any of the pots on the unit. I made sure my projector was warmed up and ready to go and then I found a little eyeglass screwdriver and started turning the pot labeled "BLK LVL". Wow! Within just a few turns I saw a difference right away. I had paused my HD DVR on a closeup scene from Bikini Destinations where the model was coming up out of the water with darkness in the background and lots of shadows on her face. Turning the gamma adjustment back and forth I began to see and understand how the control works. It was as if I had just replaced my screen with a high power, high gain material! Even better, increasing the gamma not only gave me a bump in overall brightness but it preserved the blacks as well! After some further tweaking I found that I was able to turn down my projectors brightness and contrast controls by 4 to 5 clicks each right away and the gamma adjustment in the Crescendo unit compensated for this while also making the blacks look even blacker! I only had a few hours with this last night but the improvement I am seeing is by far the best I have achieved to date with this projector (NEC XG-110). If you have a cheap transcoder and or your CRT projector appears dim and washed out or suffers from "gray" blacks, you really should check out Kim's transcoder with the gamma adjustment. This was worth every penny and I should have bought one a long time ago. I will try to post some pictures soon in my thread about the XG-110 and will post further thoughts about the Crescendo unit when I have had more time with it. Thanks Kim!

Good review, and excellent choice of source material! ;)

I have about 10 episodes of "Get Out" to watch. "But sweetie, look at those flesh tones!"

Hello,

I have a Sony kp-57ws510 crt tv. I really want to take advantage of the gamma controls on RTC2200. Problem is, this tv does not have vga inputs. It only has dvi and component. Would I need to buy a vga to component transcoder in order to use this device on my set?

Thanks.

Johnsmith,

I sent you an answer to your email address.


Kim