Sony Pearl Black levels?

ailean · 23-12-2006, 9:57 AM

Been playing with the pearl for a couple of days and having difficulty in getting it to produce good black levels. Bright scenes look very nice but dark stuff looses too much detail. I'm not certain just how much mixed brightness you need to mess up the auto iris stuff?

I had a go with the DVDO VP50 mixed WTW/BTB test patern and although white levels were fine I could see nothing at all in the two Black 1/4 of the screen. I had to turn the brightness up to ~75 on the Sony just to make out any black detail.

I figure that test definatly defeats the iris feature as it's basicly two 1/4 white and two 1/4 black.

At this setting the picture is good but looses some 3D punch with the raised black levels but at least I can see what's going on in darker areas now!

This seems to go against most settings I've seen, I did try some of the gamma modes before doing this but they didn't help much. My room is dark but walls and ceiling are light coloured and the screen is a standard matt white (may have a slight gain of 1.1) ~90" diag with a 12' throw.

Otherwise I'm fairly happy with it, only seems to have a just about 1 pixel red misconvergance.

Gary Lightfoot · 23-12-2006, 10:21 AM

I think you're meant to leave the brightness and contrast on the Sony at default values, and adjust them in the source if possible. That helps reduce any brightness compression apparently (not sure about the black levels).

Can you do that with your sources or the VP50? I would think the VP50 would have these adjustments to allow you to do that without altering the default values on the Sony.

Gary

ailean · 23-12-2006, 12:58 PM

Yeah this is what I've read. I can adjust each source at the VP50 but not all sources have test patterns and then when I switch to my LCD HDTV they'll be off again so I'll have to calibrate that to the Sony levels, making the VP50 test patterns fairly useless.

I did give that a go by eye but wasn't overly impressed, guess I'll have to dig out my DVE etc discs and try to use the DVD as a benchmark for the others, might try recording some dark film on the SkyHD box that I have on DVD to attempt to match levels.

Just takes all the joy out of xmas doing all this stuff but currently out of the two PJ and two HDTVs sitting around my living room the Pearl is the only one connected up so I do need to sort it out for the xmas TV treats!

tfboy · 23-12-2006, 1:06 PM

When I played around with my black levels, I did experiment with the settings on the pearl. In the end, I decided that brightness set much more than about 52 or 53 reduced the deepness of black and whilst it may show an infinitesimally small amount of more detail, the induced "greyness" far outweighed it.

I've left my contrast around the 80 mark too.

Using theatertek on my HTPC with the DVE disc, the above settings were what gave me the best picture as far as tweaking settings on the PJ

gandley · 23-12-2006, 2:09 PM

gamma3 will bring black levels real low at the expense of clipping black detail, or loosing shadow detail. gamma 2 pushes black level detail but ups the black level, gamma 1 is slightly better than off in that in maintains blacks but does slightly give better shadoe/black detail. i used gamma 1 for most stuff.

Also make sure black level adjust is off, as all this does is push the same level of gamma 3 and you loose shadow detail.

you wont get the deepest blacks out of the pearl unless your room is 100% bat cave. i found even the slightest bit of light will elevate blacks. In fact in many ways your room will limit blacks so that any projector will look quite similar no matter how capable they are at achieveing a deep black. So if you want mega blacks, you need a room that will allow you to go that black.

(much like how a room will limit ANSI contrast).

Adjusting the pearls level of contrast and brightness is fine if you turn off the dynamic iris, but the sony settings are optimised for use with the iris on.

in my case i now know if i want to see a projector go blacker, i need to hurry up and get all my black felt up.

ailean · 23-12-2006, 3:20 PM

Yeah I was surprised how light up the room got with the pearl considering how low its' lumens are, but then my HS20 has 700hours on the bulb which probably helps.

Noticed that the bulb is set to high on the pearl and most seem to suggest this too but for contrast I used the HS20 on the low setting, does the dynamic iris mean you want bulb on high for best results?

Black felt, although entertaining, probably will look nasty for a living room but if I was to cover the two walls and ceiling at the screen end (a 24x12' room with screen on the short wall/bay window) would it make a huge difference?

Was someone on about cheap speaker cloth or something from Maplin for this sort of thing?

My girlfriend has her own place to play with and doesn't have an issue with black but I'm not sure I'm a qualified mopey goth to live in a bat cave!

gandley · 23-12-2006, 4:27 PM

Well in high lamp mode the pearl is actually putting out a fair few lumens, at least 650, which is actally quite brite. (cosidering most dlps i had would be lucky to put out 450 lumens after calibration)

if the room is lighting up quite a bit then its dropping the black level for sure.
when it comes to projectors alot just go wow 15000:1 CR, inky blacks, yeah!! but if they have white walls etc then dream on.

Most run the pearl in high mode if there using a big screen or like the added punch, but if that punch is killing blacks then its having the wrong effect. try low mode and see if the black level improves, if it does then you know you have a light control issue, or at least the room is limiting your black level.

A screen that would reject ambient/reflected light might help if you can use it in your room (depending on PJ placement a high power screen cuts down room reflection and rejects stray light).

but go low lamp mode and see what happens to your blacks.

mjw1999 · 24-12-2006, 9:04 AM

I have the same problem in my cinema loft as all walls and ceilings are magnolia

.
I cant see us using any black felf on walls and ceilings as its also a place we like to go and sit and listen to cd. the light from the velux windows is great when you want to just sit and relax and its a great view (fully blacked out though with velux blinds), so we dont want to spoil the pleasure to much with some sort of gothic look.
we've now started to try a few darker colours in the room(just samples in small areas) such as chocholate colours which are much darker than magnolia but by no means black. however when the lights are out this new chocholate colour looks black mostly when the pj is on where as the magnolia still looks white and very light.
I now a darker chocholate paint is not the perfect solution for stoping reflected light, but how much do you this will help coming from magnolia.
heres a thread of my loft when under construction.
New Cinema loft almost finished
Tell me what you think guys. Sensible and outrages suggestions Welcome.
Thanx
Mike

Avi · 24-12-2006, 9:18 AM

Quote:

Originally Posted by mjw1999

I have the same problem in my cinema loft as all walls and ceilings are magnolia

.
I cant see us using any black felf on walls and ceilings as its also a place we like to go and sit and listen to cd. the light from the velux windows is great when you want to just sit and relax and its a great view (fully blacked out though with velux blinds), so we dont want to spoil the pleasure to much with some sort of gothic look.
we've now started to try a few darker colours in the room(just samples in small areas) such as chocholate colours which are much darker than magnolia but by no means black. however when the lights are out this new chocholate colour looks black mostly when the pj is on where as the magnolia still looks white and very light.
I now a darker chocholate paint is not the perfect solution for stoping reflected light, but how much do you this will help coming from magnolia.
heres a thread of my loft when under construction.
New Cinema loft almost finished
Tell me what you think guys. Sensible and outrages suggestions Welcome.
Thanx
Mike

As a compromise I used Craig&Rose Chocolate Velvet Matt from their Oplulence range. IMO it's a very rich colour and reduces reflection significantly compared to the ivory/white colour scheme I had before. That said I also use a chocolate velvet material and this just soaks up light like a sponge. If possible use a material such as velvet closer to the screen area and a dark rug if you have light floor covering.

AVI

mjw1999 · 24-12-2006, 9:26 AM

AVI
It would be nice to see some pics if possible. I think it would be a good improvment/compromise for me also. Where near the screen did you use the Chocholate velvet material.
Thanx
Mike

Avi · 24-12-2006, 9:57 AM

Quote:

Originally Posted by mjw1999

AVI
It would be nice to see some pics if possible. I think it would be a good improvment/compromise for me also. Where near the screen did you use the Chocholate velvet material.
Thanx
Mike

I'll post some pics when everything is back as I'm installing a new screen at the mo. I use velvet on the left, right and ceiling about 4' in to the room. I made some velvet slabs (1.4mx.5m each ) that I use on the ceiling directly in front of the screen area but these could also be used on the walls. They look a bit like acoustic treatment panals but are simply 1" thick polystyrene insulation slabs covered in velvet using double sided tape. Very cheap to make and they are relatively light so can be fixed with velcro to avoid damage.

AVI

gandley · 24-12-2006, 12:50 PM

I will be using black velvet curtains on a poll track, about 1.5m from the screen, when the screen is not in use then i can just gather the curtains to the corners of the room with a tieback, so its not permenant ugly.

i did chuck up the black maplins speaker cloth on the ceiling also about 1.5m in front of the screen and that did make a big difference. seems my ceiling is doing most damage. the cloth also did not look that bad once up neatly.

Laying a black velvet curtain in front of the screen again shut down alot more reflection, and its interesting to not that the reflection before black covering used to reach halfway into the room, ie the walls would light up that far up. with black in place (all loose hang as the curtains are being made properly next week) room reflection had gone.

my friend has a room but its like 30ft, 25ft and the screen he has is cental in the 25ft width of the room, he has light colour but gets no where near the relection i do as his screen is not close to the walls.

My problem is my screen is close to the wall for the first 1.5m and then the room opens out, covering just that first 1.5m does the trick big time.

Now i just need to get it all done properly.

tfboy · 24-12-2006, 1:08 PM

Regarding curtains, I did have one thought: what about curtains which are black on one side, but a pleasant bright magnolia on the other.

Then fit them on a track which is in fact a "loop" so you have them one way round for everyday pleasing light and then turn them around to have your bat cave for home cinema viewing.

I'm thinking of doing this to my lounge, with a small pelmet drop in front about 10cm away from the wall so you don't see the track where the curtain hangs.

gandley · 24-12-2006, 1:13 PM

i think i prefer black to magnolia, god if i ever stick magnolia onthe walls then i will truly have become my father.

ailean · 27-12-2006, 2:49 PM

I'm running with low lamp and gamma1 at the moment with brightness raised at the source (via the VP50) and it seems better.

I did however do a little test regarding room reflections, with the VP50 test pattern on (screen divided into 4 blocks, two white with near & wtw bars and two black with near & btb bars) I stood in front of the lens and physically blocked out the two white blocks. This plunged the room into darkness but I could still not see any bars on the two black bars with default settings on the Pearl.

So it's not reflections killing my black detail so I think it must be the fact that the test screen is 2/4 white and kicking the Iris into a crappy black mode.

I'll have to see if there are some btb tests on AVIA & DVE that don't have much white/bright areas.

Gary Lightfoot · 27-12-2006, 3:11 PM

If the VP50 is generating those test images and you can't see the black bars, can you use the VP50 to raise the brightness to make them visible?

Gary