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anyone using ND filters to increase black levels on entry projectors (hd20)

post #1 of 65
Thread Starter 
as the title states, i have my first projector (an optoma hd20) on the way.. I didnt want to spend an arm and a leg on my first projector until im sure i like it.. the only major knock that really concerns me on these entry 1080p projectors is black level, and i saw on a thread here about the epson 705 hd that they use ND filters to improve the black levels..

wondering what size you guys reccomend for the HD20 and what results if any anyone has experienced.
post #2 of 65
Please edit your post and link the thread you mentioned (for those of us who've never heard of ND filters and want to get some background knowledge.)
post #3 of 65
My first question would be...how are the black levels in a totally dark room? ANY light will have a negative impact on the image.
post #4 of 65
Thread Starter 
Quote:
Originally Posted by Donny Bahama View Post

Please edit your post and link the thread you mentioned (for those of us who've never heard of ND filters and want to get some background knowledge.)

i dont have the exact post handy, but it was in the epson 705 hd owners thread iirc..

Quote:
Originally Posted by Sheridan1952 View Post

My first question would be...how are the black levels in a totally dark room? ANY light will have a negative impact on the image.


will have to report back after it gets here (monday) was hoping someone would have some input so i can get a filter bought off ebay and have it show up here around the same time as my screen (about 10 days out)

post #5 of 65
You can try it, I'm only saying that the blacks are only as good as how the dark the room is. As an illustration, I'm including the link to another person's website where he clearly shows the effects of ambient light on a screen.

http://www.avintegrated.com/lighting.html
post #6 of 65
yes lighting has a huge impact on black level... but, with my current dlp projector, you can have a small amount of light in the room and you can still see the "gray" blacks, as in, the black level can't go darker than that.

I have considered an ND filter, but never actually got around to trying one, I think I would be willing to live with the compromise of slightly lowered brightness for slightly lowered black levels.

Please post back on your results if you do try it!
post #7 of 65
Thread Starter 
Quote:
Originally Posted by Sheridan1952 View Post

You can try it, I'm only saying that the blacks are only as good as how the dark the room is. As an illustration, I'm including the link to another person's website where he clearly shows the effects of ambient light on a screen.

http://www.avintegrated.com/lighting.html


good info in that link, while the room is totally light controlled (can be pitch black, ie batcave).. there will be times when there is some ambient light on (sports or games with people over, or if i just dont feel like sitting in the dark)

so the plan is to remove the ND filter when you go to 'bright' mode, and put it back on for movie in the dark mode..

ordered one on ebay for 9 bucks, so if i hate it its not like it was a big expense, will post results once its here

post #8 of 65
Quote:
Originally Posted by cream puff View Post

good info in that link, while the room is totally light controlled (can be pitch black, ie batcave).. there will be times when there is some ambient light on (sports or games with people over, or if i just dont feel like sitting in the dark)

so the plan is to remove the ND filter when you go to 'bright' mode, and put it back on for movie in the dark mode..

ordered one on ebay for 9 bucks, so if i hate it its not like it was a big expense, will post results once its here


Make very sure its a glass lens and not a plastic lens. The lamp generates a lot of heat and could melt a plastic lens.
post #9 of 65
Thread Starter 
Quote:
Originally Posted by dswdallas View Post

Make very sure its a glass lens and not a plastic lens. The lamp generates a lot of heat and could melt a plastic lens.



i did, and its a glass.. in the above thread i mentioned where i learned of the 'trick' guys had plastic ones that had hot spots melt in them and the picture got all fuzzy lol
post #10 of 65
not an ND filter, but I have been using a 81EF warming filter on my HD20. Lowers the black level, and with a color calibration to compensate for imbalance, there is a noticable increase in contrast without sacrificing too much brightness. I have calibrated two modes. One for cinema viewing in a dark environment, and one for bright viewing with some abient light present.


So far I am liking the results...
post #11 of 65
Any pics ?
post #12 of 65
Thread Starter 
alright guys have everything all set up and the ND filter came in today.

optoma HD 20, 120 inch matt white screen (a cheapo one)

calibration per the avs HD 20 user thread.

pic is with my iphone at about 6 ft from the screen, no processing done to the pic other than cropping.. left the image a little bit 'off' so its easy to tell where the split is.

I am VERY happy with how the ND filter improved the blacks, went from obviously grey, to very nearly black and only a little grey if you are 'searching' for it in a almost all black screen, considering I have white walls and roof, I dont think you can do much better without changing the room itself..


heres a pic showing the change, the nd4 is a little too dark for this projector, made the image look a little 'flat', where with the ND2 the picture looks almost identical in bright screens and grey.. just took a little bit of the punch out of the bulb making the blacks blacker.. optoma HD20UB? lol




post #13 of 65
very very nice indeed, but where did you buy that?
post #14 of 65
Thread Starter 
ebay, they are like ~10 bucks.. just gotta make sure its glass not plastic

also any camera shop would carry them if you want to buy local
post #15 of 65
in black the nd filter seem working amazing but how about other colours? can you take some pics in a movie with many colours to see how they appear with nd filter?
post #16 of 65
What size for the optoma? I want to try this!
post #17 of 65
Quote:
Originally Posted by p_sousa View Post
in black the nd filter seem working amazing but how about other colours? can you take some pics in a movie with many colours to see how they appear with nd filter?
For those not familiar with what neutral density filter does, it just reduce light output equally across the visual spectrum.. assuming it is a quality filter. If the quality is low, it will effect color. It is just like sunglasses for your projector.. This is the same principle an iris works on, reducing the light output so the bright areas of the screen do not was out the neighboring dark areas.
post #18 of 65
thanks for the explanation
post #19 of 65
Quote:
Originally Posted by conradjohnsonfan View Post
not an ND filter, but I have been using a 81EF warming filter on my HD20. Lowers the black level, and with a color calibration to compensate for imbalance, there is a noticable increase in contrast without sacrificing too much brightness. I have calibrated two modes. One for cinema viewing in a dark environment, and one for bright viewing with some abient light present.


So far I am liking the results...
Okay, now you are taking filters to the next level. Not just reducing both peak white and black floor. Where do you purchase these filters? How do you calibrate colors?
post #20 of 65
What size filter for the Hd20 PLEASE??????
post #21 of 65
Thread Starter 
the filter is a 77mm, fits perfect over the focus ring, i stuck a tiny strip of tape on the edge of the filter, to hold it in place incase i bump the projector, but it sits up there without any tape if you wish also.

and as said, it does not effect the color other than whites go a tint closer to grey (like looking at something white wearing sunglasses).. although that is far less distracting than the greyish blacks.. i greatly prefer the filter on.
post #22 of 65
Very interesting, I wonder why more people don't use these. I love the cheap price.

More pictures please, something with lots of color.
post #23 of 65
I was using one on a Mitsubishi HC4000, 67mm Hoya. It actually slid right inside the lens rim. It acted like a lens cover as well. Made a nice difference in black level, yet whites still looked white. Funny how the eye works. Half the brightness of white may not look like it, yet half of the black level is very noticeable.
post #24 of 65
can you put pics of diference in whites ?
post #25 of 65
I think in pics, the difference in whites will be much more noticeable than when actually watching in the dark. These filters are less than 20 bucks so why not try it yourself. I have had one for 6 years and have used it more than I ever thought I would. Helps with 3d projectors when you want to watch 2d on them since they are so bright, especially with a high power screen.
post #26 of 65
NEC used to warn in their manuals (HT1000) many years ago not to use ND filters because of heat being absorbed by the filter, which could then damage the projector. Now, a filter is a lot cheaper than a grey screen, but do ND filters deflect heat back into the projector? I don't want to do anything that's going to cause the DMD chip to overheat in my new projector and then develop stuck pixels.
post #27 of 65
Does the ND filter on the HD20 improve black levels to a point where it's similar to a Panasonic AE4000 ? Or better than a Mitsubishi HC4000 ? Just would like to get a feel for the kind of improvement an ND filter would give if we compare to a some other projectors.
post #28 of 65
cream puff
Thanks for stepping up and doing this. What the heck, I just ordered one off of fleabay and I'll give it a go. I'm pretty satisfied with my HD20 but after demoing a HC4000 and viewing a BenQ W6000 a while ago the want for better blacks is in the back of my mind.

If this works it could satisfy the urge of 'upgraditus' for a while.
post #29 of 65
Please give us an update after you've received your filter.
post #30 of 65
Just ordered mine from eBay. I'll update when I receive it!
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