Optoma H79 review & screenshots - Page 7 - AVS Forum
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post #181 of 2404 Old 02-18-2005, 06:54 AM
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Quote:


Originally posted by mandarax
Tom ..

I just got all my promo stuff from Optoma this morning. On spec they show the brightness over the H77 being 10% brighter.

From my viewing (with no measurements), it seems to more like 20% brighter than the H77 (on my 100" Firehawk). Blacks are incredible...
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post #182 of 2404 Old 02-18-2005, 07:00 AM - Thread Starter
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Robert, the H79 looks allot brighter from what I remember of day 1 with the H77. I'll get the H77 going and run a light meter test on a bulb that has 900hrs on it. The H79 has 61hrs right now.

I asked Optoma's engineer yesterday about the brightness, he said the mirrors on the chip are actually a little larger than the last chip. Which is why people were noticing a better fill. He said the larger area plus not losing light between the pixels is the reason it's brighter.

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post #183 of 2404 Old 02-18-2005, 07:27 AM
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Quote:


Originally posted by guitarman
Measurement was straight ftcdles, 14' 92"widecreen, 17.25 ftcdles

Cool. That's triple the measurment I got on the other brand with the same meter at 14', but with a slightly wider (110") screen. Very nice indeed. Even at 50% dimming with age, it woudl presumably be brighter than the other unit I saw.

So by my (possibly incorrect) calculations:
Other PJ I measured meas 5.69fc, 204 lumens on my 110" (36ft2) screen

H79 with your setup:
Screen area 92"x52"=33ft2
17.25fc * 33ft2 = 570 lumens

Thanks for the report and double check. Numbers look good there.

Cheers,
Scott
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post #184 of 2404 Old 02-18-2005, 07:33 AM
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[quote]H79 with your setup:
Screen area 92"x52"=33ft2
17.25fc * 33ft2 = 570 lumens[\\Quote]

570 lumens????? That is just over half of their 1000 lumens advertisment. Wonder if the contrast ratio number is off that much?

Frank
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post #185 of 2404 Old 02-18-2005, 07:39 AM
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570 lumens????? That is just over half of their 1000 lumens advertisment. Wonder if the contrast ratio number is off that much

Keep in mind here that my calcs are my best guess at understanding this and may be wrong. But what is not apparantly wrong is the Fc measurment. No room for calc errors there, it's just a light meter reading. And it was 3 times the reading I got off another DLP at the same distance, and not too much different projection width.

FYI Gary's calcs were different than mine. I'm not looking to compare mfgr specs, only popular PJ's. The other PJ was reputed to be bright but I didn't get that result. That, too may have been my fault and inability to adjust it properly, or some other problem. But in any event, Tom's reported meas. was 3 times as bright as the one I took with the same brand and model meter. There could be meter differences too, but I wouldn't think they would be drastic.
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post #186 of 2404 Old 02-18-2005, 08:19 AM - Thread Starter
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[quote]Originally posted by ftlee
Quote:


H79 with your setup:
Screen area 92"x52"=33ft2
17.25fc * 33ft2 = 570 lumens[\\Quote]

570 lumens????? That is just over half of their 1000 lumens advertisment. Wonder if the contrast ratio number is off that much?

Frank

That's a huge calibrated brightness level. Most PJ's come in at the under 300 level, closer to 200. I think once I read 388 which must hv been the IF7200. I just hope my low reading is right. I couldn't get a reading at the screen, half way to the PJ I got .001 which was the first time the meter would read anything. Closer 3' from the lens I got .002 mostly but if I went a little closer it would go to .003

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post #187 of 2404 Old 02-18-2005, 08:43 AM
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Quote:


Originally posted by scotthorton
Keep in mind here that my calcs are my best guess at understanding this and may be wrong. But what is not apparantly wrong is the Fc measurment. No room for calc errors there, it's just a light meter reading. And it was 3 times the reading I got off another DLP at the same distance, and not too much different projection width.

The difference in screen size between 110" wide and 92" wide is that the bigger screen is 43% more area (or the smaller screen is 30% less area). If this is what you meant for widths it accounts for some of the difference, but not nearly all off it.

Quote:


Originally posted by guitarman
That's a huge calibrated brightness level. Most PJ's come in at the under 300 level, closer to 200. I think once I read 388 which must hv been the IF7200. I just hope my low reading is right. I couldn't get a reading at the screen, half way to the PJ I got .001 which was the first time the meter would read anything. Closer 3' from the lens I got .002 mostly but if I went a little closer it would go to .003

Sounds like you may have to get very close to get a reasonable idea of CR. If you can, I would try going close enough to read about 0.005 and then measure 100 IRE from there also (then divide). If the 100 IRE saturates the meter, then you could measure "black" and 20 IRE from up that close. Then measure 20 IRE and 100 IRE at the screen. Then you would get the total CR just by multipling the 2 ratios:

CR = ( (20 IRE up close) / ("black up close) ) * ( (100 IRE at screen) / (20 IRE at screen)

Also, you may get more accuracy down low by switching to Lux on your meter instead of Fc. Then just use the Lux setting for all measurements if it works.

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post #188 of 2404 Old 02-18-2005, 08:51 AM
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Quote:


Originally posted by darinp2
[b]The difference in screen size between 110" wide and 92" wide is that the bigger screen is 43% more area (or the smaller screen is 30% less area). If this is what you meant for widths it accounts for some of the difference, but not nearly all off it.

Sorry, probably my fault. It's not 110" wide and 92" wide. Mine is 110" diag, Tom's is 106" diag (~92 wide). So the difference is between a 110", and a 106" and my square footage calcs were based on those sizes.
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post #189 of 2404 Old 02-18-2005, 08:56 AM
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Quote:


Originally posted by scotthorton
Sorry, probably my fault. I't not 110" wide and 92" wide. Mine is 110" diag, Toms is 106" diag (92 wide). So the difference is between a 110", and a 106" and my square footage calcs were based on those sizes.

Thanks.

I think that people who have been around here a while mostly know that the vast majority of these projectors put out much less light after calibration than specs. I would consider 570 lumens to be pretty good for a projector like this, especially if it maintains good CR at that.

Tom,

Was your 17 Fc number with it in bright mode? In other words, was that white peaking option (or whatever it is called) on or off?

Thanks,
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post #190 of 2404 Old 02-18-2005, 09:02 AM - Thread Starter
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White peak off, econo lamp mode, tuned down contrast and black level, then did a grayscale tuning, rechecked the contrast and brights after the tuning and they stayed correctly. Really it's an excellent brightness level because again right now I got the curtains open and a light on 3' in front of the screen. Just amazing that the colors are still strong and not washed with this. Users that like low light in the background will have no problem.

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post #191 of 2404 Old 02-18-2005, 09:33 AM - Thread Starter
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Here's some very interesting info - I just got HT-mags latest edition and Geof Morrison tests four hot projectors.

1. Mits HC900, 84" wide mat white, 100IRE 8.401ftl, black IRE 0.005, CR on/off 1680.1, Ansi CR (black & white boxes) 417.1

2. Panasonic AE700 100IRE 13.5ftl, black 0.019, on/off 711.1, ansi 161.1

3. Sony HS51 100IRE 7.701ftl, black 0.003, on/off 2567.1, ansi 162.1 (pay notice to ansi.

4. Yamaha DPX-1100 100IRE 9.351, black 0.002, on/off 4675.1, ansi 510.1

Ok re ANSI, I always thought the IRIS concept isn't an accurate way to get true better contrast. Mainly because yes you can measure a closed Iris for black and it will be low and than an opened IRIS at 100IRE and it will be high. But it can't be at both places at the same time. Therefore the ANSI differences, Note the DLP's can do better.

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post #192 of 2404 Old 02-18-2005, 09:40 AM
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Quote:


Originally posted by guitarman
Here's some very interesting info - I just got HT-mags latest edition and Geof Morrison tests four hot projectors.

1. Mits HC900, 84" wide mat white, 100IRE 8.401ftl, black IRE 0.005, CR on/off 1680.1, Ansi CR (black & white boxes) 417.1

2. Panasonic AE700 100IRE 13.5ftl, black 0.019, on/off 711.1, ansi 161.1

3. Sony HS51 100IRE 7.701ftl, black 0.003, on/off 2567.1, ansi 162.1 (pay notice to ansi.

4. Yamaha DPX-1100 100IRE 9.351, black 0.002, on/off 4675.1, ansi 510.1

Ok re ANSI, I always thought the IRIS concept isn't an accurate way to get true better contrast. Mainly because yes you can measure a closed Iris for black and it will be low and than an opened IRIS at 100IRE and it will be high. But it can't be at both places at the same time. Therefore the ANSI differences, Note the DLP's can do better.

The ANSI CR is the checkerboard or white and black and really doesn't relate to the iris changes you mentioned. And nobody measures 100 IRE with the iris open and 0 IRE with the iris closed. They would get completely trashed if they did that (and Sharp could have claimed more than 12000:1). The on/off CR numbers mentioned are at a fixed iris position. It comes at lower lumens, but it is real CR.

As far as that 4675:1 number, I don't believe it. He has exactly one significant digit in his black level reading (0.002) and gives us 4 significant digits in the final number. This is completely invalid. A 9.351 to 0.002 ratio basically gives a range of 3100:1 to 9400:1, since the least significant digit is basically + or - 0.001 in the black level reading. And given that even Yamaha only rates the projector at 4000:1 I would say that the actual number is closer to the 3100:1 end. I've mentioned before that as CR numbers go up those who continue to take readings off screens at normal image sizes will get very inaccurate numbers. I bet this is a case of that.

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post #193 of 2404 Old 02-18-2005, 10:05 AM - Thread Starter
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I wondered if he aims the Minolta at the screen. I'll see what he got with the 12k, that ought to give us a better idea. He probably used the same method with each.

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post #194 of 2404 Old 02-18-2005, 10:15 AM
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I think the Infocus 7205 gets very close to their published specs. Isn't it 890 lumens calibrated? Anyone know what the 300E is getting?

Frank
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post #195 of 2404 Old 02-18-2005, 10:20 AM
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Quote:


Originally posted by guitarman
I wondered if he aims the Minolta at the screen. I'll see what he got with the 12k, that ought to give us a better idea. He probably used the same method with each.

I think he was pretty close with the 12k. But when you use a method that is faulty you always have a chance of coming close. Especially if you measure, get a number that doesn't make sense, and measure again until one does. It doesn't mean it is accurate though. I believe he uses the Minolta LS100 off the screen.

It is also possible that Yamaha claims 4000:1 with white peaking on, but actually delivers 4675:1 with white peaking off after calibration. Highly unlikely IMO, though.

If your H79 is around 3000:1 after calibration with white peaking off I would consider that very good at the lumens you are getting.

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post #196 of 2404 Old 02-18-2005, 10:46 AM
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Grubert..... I have been given dates for the releases of the BenQ 8720, and the 7700 .... however the source is conflicting with other information received so have decided to not I do a large annual shootout and it is usually in the beginning of April... I don't think I am going to have a problem attaining the Optoma line up for the shootout and will most certainly want to get the BenQ lineup as a direct comparison. I saw the 7700 at CES but it was in a room with their rptv... so it was hard to discern what it looked like or would look like in a better environment. In any event this BQ info does not really belong in this thread..

Robert
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post #197 of 2404 Old 02-18-2005, 12:04 PM - Thread Starter
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"Sounds like you may have to get very close to get a reasonable idea of CR. If you can, I would try going close enough to read about 0.005 and then measure 100 IRE from there also (then divide). If the 100 IRE saturates the meter, then you could measure "black" and 20 IRE from up that close. Then measure 20 IRE and 100 IRE at the screen. Then you would get the total CR just by multipling the 2 ratios:

CR = ( (20 IRE up close) / ("black up close) ) * ( (100 IRE at screen) / (20 IRE at screen)

Also, you may get more accuracy down low by switching to Lux on your meter instead of Fc. Then just use the Lux setting for all measurements if it works."

I give it a try but do think the 100IRE will be way high at those closer levels. Since I already got .003 a few feet away, if at that point I can get a 100IRE reading and it's way higher, it should be a pretty high cr reading. Back to wait until dark.

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post #198 of 2404 Old 02-18-2005, 12:07 PM
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Guitarman:

I don't mean to be bitchy or rude. I don't enjoy forum flame wars, but I would really like to know something. Have you entered into an agreement with Optoma, AVS, or some other third party NOT to post objective data regarding the H79's CR? You have now had this PJ for 10 days. You have all the necessary equipment. You have posted numerous (pretty but useless) screenshots, color and gamma data, and now CR data (measured by others) for OTHER PJs, but you still have not provided this rather basic and critical information for the PJ you presumably set out to "review."

If this information is buried somewhere in this now very long thread and I simply missed it, then I apologize. Otherwise, would you please post this data immediately or at least explain to the readers of this thread why you are either unable or unwilling to do so?

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post #199 of 2404 Old 02-18-2005, 12:26 PM
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darinp2

How does the staged measure work - isn't the gamma going to pollute the numbers?

guitarman
If this meter is working out - can you PM me WTB? Would like something cheap to double check the Spyder!

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give guitarman the benefit of the doubt on this one - some of us had calibration equipment for years - and you can see we are still trying to figure out how to measure high contrast accurately.

Calibrated numbers are important for knowing how to do a proper setup - but one only needs to read the review magazines to know that nearly every manufacturer is cheating the numbers to be as large as they can. Some people are happy watching blue color temps with vivid gammas - and for them they get the advertised numbers.


If you could get Alan Gouger to provide the brightness/contrast numbers in his Sim2 review that he raved about - then that would be good as well!
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post #200 of 2404 Old 02-18-2005, 12:36 PM - Thread Starter
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Yes Tom must hv missed the fact that we're trying to figure the best way to use the light meter. It's in the last few pages. At least I got the brightness reading for a 92" widescreen at 14'away, it's pretty bright. This is the light meter the the Smart guy uses. It's good point is it reads very low and has a 3% x/- error factor.

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post #201 of 2404 Old 02-18-2005, 12:46 PM
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Quote:


If this meter is working out - can you PM me WTB? Would like something cheap to double check the Spyder!

kras: I hunted quite a bit never did find it any cheaper new. www.davis.com has an assortment of them. The one I (and Tom) have is the long, slender one. About $119 new everywhere.
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post #202 of 2404 Old 02-18-2005, 01:10 PM
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Hi Tom,

I calculated my own numbers from your figures and they concur with Scotts, so hopefully we're both right.

Are you sure that's in low lamp mode though? I was getting 510 in high lamp and 389 in low lamp mode in calibrated conditions.

You did say that you didn't use red as your limiting color, so that may explain why you have higher lumens - you will have a higher overall contrast setting. You should also have a much better contrast ratio because of it.

If so your 570 is a little over 10% better if it was high lamp, and over 30% if it was low lamp. How many hours on the lamp? My readings were at around 60 hours IIRC. They're pretty impressive figures if accurate - the low lamp mode is higher than the H77 high lamp mode.

If you take readings using lux, and multiply by the screens area in square meters (3.07) then you will end up with Lumens (multiply by the screens gain if it has any). Divide the lumens by the screens area in square feet, and you will get ft lamberts.

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post #203 of 2404 Old 02-18-2005, 01:19 PM
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"...the mirrors on the chip are actually a little larger than the last chip. Which is why people were noticing a better fill. He said the larger area plus not losing light between the pixels is the reason it's brighter."

Fill factor was already better than 90%, I don't see how making them very slightly bigger could have a discernible effect on brightness.

Seems like the lower hour lamp will explain most or all of the brightness difference.

Noah
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post #204 of 2404 Old 02-18-2005, 01:24 PM
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Seems like the lower hour lamp will explain most or all of the brightness difference.

What lower hr lamp? DId I miss that tidbit in the new specs? Not 3000 anymore?
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post #205 of 2404 Old 02-18-2005, 01:37 PM - Thread Starter
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Quote:


Originally posted by Gary Lightfoot
Hi Tom,

I calculated my own numbers from your figures and they concur with Scotts, so hopefully we're both right.

Are you sure that's in low lamp mode though? I was getting 510 in high lamp and 389 in low lamp mode in calibrated conditions.

You did say that you didn't use red as your limiting color, so that may explain why you have higher lumens - you will have a higher overall contrast setting. You should also have a much better contrast ratio because of it.

If so your 570 is a little over 10% better if it was high lamp, and over 30% if it was low lamp. How many hours on the lamp? My readings were at around 60 hours IIRC. They're pretty impressive figures if accurate - the low lamp mode is higher than the H77 high lamp mode.

If you take readings using lux, and multiply by the screens area in square meters (3.07) then you will end up with Lumens (multiply by the screens gain if it has any). Divide the lumens by the screens area in square feet, and you will get ft lamberts.

Gary.

First Kras the meter is an Extech 403125.

Gary, right that's with the recent re-tune not using red as a limiting color. Definetly In econo, 60hrs on the bulb. The contrast does look way better from using the other method. Plus the gamma was better 2.26 I think. Which is why I didn't want to mess with it. Looks perfect right now.

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post #206 of 2404 Old 02-18-2005, 01:41 PM - Thread Starter
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Quote:


Originally posted by noah katz
"...the mirrors on the chip are actually a little larger than the last chip. Which is why people were noticing a better fill. He said the larger area plus not losing light between the pixels is the reason it's brighter."

Fill factor was already better than 90%, I don't see how making them very slightly bigger could have a discernible effect on brightness.

Seems like the lower hour lamp will explain most or all of the brightness difference.

Hi,
I don't build them but Wing does and he has all the facts from going to Ti's factory. I don't think he's making it up.

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post #207 of 2404 Old 02-18-2005, 01:46 PM
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Quote:


we're trying to figure the best way to use the light meter

OK, but gee I guess I don't understand why all the Sturm and Drang about this. ColorFacts has a wizard for this. Just aim the trichomat well, place it close enough to get a reasonably high black level reading, and then run the wizard. Even if the meter is off (the ColorFacts forum suggests that it overstates luminance by about 10%), since CR is a RATIO, I don't see how this matters. I whatever the error, it would appear for black as well as full on white. I've read quite a bit about the Trichomat being an unreliable device to measure color at low light levels, but a good CR number does not depend upon a precise color measurement.

Are you guys saying that the Trichomat's Foot Lambert reading is so wildy inaccurate (a variance of greater than say +- 10%) that it's totally useless for CR measurments? If you are, then Mark Hunter needs to know about this.

Tom Huffman
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post #208 of 2404 Old 02-18-2005, 01:54 PM - Thread Starter
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I'l quote JimmyR's reply to me.

"You can't get an accurate CR reading with a colormeter from colorfacts!"

Something like that. Looks like we got a pretty good light meter going. I just have to try Darin's tip of getting both readings at the same distance. Probably tonight when the sun goes down.

Tom/guitarman
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post #209 of 2404 Old 02-18-2005, 02:02 PM
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Quote:


Originally posted by vjren
Given the fact that temporal dithering is still an issue for some. I'd like to know how the H79 does the pan in the begining scene from fith element where the boy comes in and the pan starts over the column. The letter in the column are breaking apart there on many projectors. (Mitsubishi has it covered, as Li-on determined, they somehow managed to fix it! (HC900 HC2000) )

Another sequence is the opening menu of MIB-II right after you press play. The colums moves to the right breakes apart from temporal dithering.

So guitarman or other H79 early adopter, is there any difference there, how does it look?


The problem you mention mitsubishi fixed is the clay face problem with PAL unit? What about panning probleme? Any of them on the HC2000 or the were able to fix it?

Bruno
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post #210 of 2404 Old 02-18-2005, 02:06 PM
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Tom, re: CR check after dark... There you go. I think you'll find you won't saturate that meter.

Set it to it's lowest scale (2 decimal places). Move it around until you get a decent reading at 0 IRE. Now, wherever that is, find something to mount the business end of your meter. That plug in box on top with the sensor comes loose if you didn't know already, the "feet" plugged into the meter body are just a holder. Now, with it mounted or stable in your location, take another dark reading at 0 IRE. Now put up 100IRE. Take a reading from your meter. You will have to change the range until you ge t a reading. As always, the lowest range you can get (most decimal points). If you hit that last range, you add a zero to the reading (x10 in the display).

Now you've got your 2 accurate numbers for the on-off CR. What's important is to have the meter head still when and between taking the 2 readings. That's why it's good to disconnect it from the handle so you don't move it when changing the ranges with the button.

Also, just to be sure, your meter should have a little tiny white diffuser disc in the sensor. When you remove the lens cap, and look into it you shoudl see white. It's about 1/4 to 3/8" in diameter. It does come out and will give higher readings if not there, so you want to be sure you have it in.

HTH,
Scott
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