JVC DLA-HD1/HD100 Owners' Thread

MeanDorris

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Hi,

I thought I would start one of these up as oddly there doesn't seem to be one on here. There is various good info dotted around the forum but thought it would be a good idea to try to keep it in one place going forward. :D

I have a few queries to start with from reading some other threads.

a) I have been interested in some owners' comments using filters with these models, specifically an ND2.

My projector is located in my main living room so is far from light controlled, I have blackouts on the curtains but there is still a good bit of light leakage during the day, however, when it gets dark it's obviously not a problem and all my AV kit is housed outside the room so there is no light spill from any LED's etc.

I am interested in what would happen if I applied an ND2 filter. From what I have read it seems to increase black levels but reduces the brightness (forgive my ignorance, but does the black level reduce because the overall brightness is reduced or is this a side effect of something else the filter is doing?).

I had a go at calibrating the PJ a few weeks ago with an eye one probe and HFCR and from memory was getting an Ftl reading of around 12 (I currently have about 900ish hours on the lamp).

Am I correct in assuming that an ND2 filter would reduce this brightness considerably? If so, am I also correct thinking that this would still be acceptable during night/dark conditions but may be problematic during day viewings?

b) Colour setting: I am interested at what colour setting people are running their units at. When I did the initial calibration I was mostly concentrating on contrast/brightness and grey scale and didn't do the red as a percentage of 100% IRE measurement.

c) Gamma: Also any owners who have calibrated your units, how did your gamma look and on what setting. I found that my reading was low (can't remember exactly but around 1.7 I think) and wasn't anything like a straight curve - will adding an ND2 filter have an effect/improve the gamma level?
 
a) An ND2 filter will exactly halve the light output from the projector.
So if you're getting 12ftL then you'll get 6 when you add the filter.
The eye doesn't judge it as a halving of the brightness though - there are some links somewhere to help you guestimate how much of a drop you'll perceive.

So yes, they improve black level by halving it. But they also do the same to white level.

Whether 6ftL is too dim for your environment will require some testing. A filter is about £30 from the US on ebay, so perhaps worth trying. It sounds a little low to me, unless your measurement was before taking screen gain into account, etc.

I am on roughly this level of brightness (sub 10) on my Barco BG808 and it's fine, although many on here would disagree.

b) ND filters aren't perfect so it's likely that everything will need recalibrating to get the balance you already have. you may also prefer a different setup once the image is dimmer too. In theory though, if the ND filter was perfect, then it wouldn't effect gamma.

hth
tt
 
a) I have been interested in some owners' comments using filters with these models, specifically an ND2.

My projector is located in my main living room so is far from light controlled, I have blackouts on the curtains but there is still a good bit of light leakage during the day, however, when it gets dark it's obviously not a problem and all my AV kit is housed outside the room so there is no light spill from any LED's etc.

I am interested in what would happen if I applied an ND2 filter. From what I have read it seems to increase black levels but reduces the brightness (forgive my ignorance, but does the black level reduce because the overall brightness is reduced or is this a side effect of something else the filter is doing?).

An ND filter reduces the light output hence the improved black but lower overall brightness. An ND2 will reduce light output by approx 50%, ND4 by 75% etc. There can also be side affects such as a reduction in ANSI contrast due to the additional optics in the path.

AVI
 
I put a Cokin ND4 in front of mine last night and the image hitting the filter looked very magenta.
AVI, did the square of light on the filter look more magenta than the one on the lens with your ND filters?
My Cokin is just a flat peice of glass so it wasn't intended for installation, but I wanted to see what the HD1 looked like matched to the brightness of my Barco.
 
Thanks,

I think I have found the right filter here and will give it a go:

Hoya 72mm HMC NDX2 (744) - Warehouse Express

There was some discussion about the sizes - has everyone who has used one of these gone for the 72mm or will the 77mm fit/attach easily.

Also there has been mention of mounting it in reverse? Why does that matter and what effect does it have? - I'm assuming reverse means the threaded side pointing away from the projector?
 
AVI, did the square of light on the filter look more magenta than the one on the lens with your ND filters?

To be honest I can't recall but I was using the Hoya HMC flavour if that makes a difference. I still have the filter hanging around somewhere and the next time I do a cal I'll check what difference it makes to colour.

AVI
 
Thanks,

I think I have found the right filter here and will give it a go:

Hoya 72mm HMC NDX2 (744) - Warehouse Express

There was some discussion about the sizes - has everyone who has used one of these gone for the 72mm or will the 77mm fit/attach easily.

Also there has been mention of mounting it in reverse? Why does that matter and what effect does it have? - I'm assuming reverse means the threaded side pointing away from the projector?


I used the 67mm model housed in a tube that slipped over the PJ lens and allowed the filter to be angled.

AVI
 
Hi Avi,

Was that just a custom diy job? What kind of tube?

Does the filter need to be angled?
 
Hi Avi,

Was that just a custom diy job? What kind of tube?

Does the filter need to be angled?

Yes it was a DIY job. I just happened to have some cardboard tubing that was a match for the PJ lens size. It made adding of removing the filter very quick an easy. Another method is to cut a hole in the lens cap to allow the filter thread to screw in.

It doesn't need to be angled but I recall reading it can help direct reflection.

AVI
 
Thanks,

I think I have found the right filter here and will give it a go:

Hoya 72mm HMC NDX2 (744) - Warehouse Express

There was some discussion about the sizes - has everyone who has used one of these gone for the 72mm or will the 77mm fit/attach easily.

Also there has been mention of mounting it in reverse? Why does that matter and what effect does it have? - I'm assuming reverse means the threaded side pointing away from the projector?
I used a 77mm. Hoya HMC ND2. This can be fitted very easily as it is a loose fit inside the rim of the lens. I used a few layers of black pvc tape wrapped around the thread of the filter until it was a snug push fit.
It stayed in position without ever falling out.

The filter is designed for camera use, where the light passes from the outside through the lens. In the case of a projector, the light pases through the filter from the inside. So the theory is that the filter coating needs to be facing the light source to be most effective.
Whilst I can understand the theory, I never detected any difference myself, but others claimed they could.
 
The filter is designed for camera use, where the light passes from the outside through the lens. In the case of a projector, the light pases through the filter from the inside. So the theory is that the filter coating needs to be facing the light source to be most effective.
Whilst I can understand the theory, I never detected any difference myself, but others claimed they could.

Isn't the coating to reduce reflection between the camera lens and the filter rather than the outside ? Same principle applies with PJ's in that it's inter-glass reflection that we are trying to reduce so I believe the thread should face the PJ lens (assuming the filter isn't coated on both sides and it makes no difference). :)

AVI
 
a) An ND2 filter will exactly halve the light output from the projector.
So if you're getting 12ftL then you'll get 6 when you add the filter.
The eye doesn't judge it as a halving of the brightness though - there are some links somewhere to help you guestimate how much of a drop you'll perceive.

Because we see in a non linear fashion, an 82% drop in lumens is perceived as a 50% drop in brightness (hence an 18% Kodak Grey card), so a 50% drop won't seem as much as it is.

I am on roughly this level of brightness (sub 10) on my Barco BG808 and it's fine, although many on here would disagree.

I also prefer a lower level of reflectance since I find it looks more cinematic and makes SD material more acceptable than brighter levels might.


b) ND filters aren't perfect so it's likely that everything will need recalibrating to get the balance you already have. you may also prefer a different setup once the image is dimmer too. In theory though, if the ND filter was perfect, then it wouldn't effect gamma.


IIRC, there was something like a 200K difference in colour temp with a Hoya ND2 filter due to a slight change in Green compared to Blue and Red. Cokin resin/plastic filters tend to have a much bigger effect with ANSI than the glass filters. The effect is quite visible in comparison so I wouldn't recommend them unless for experimentation.

Gary
 
Thanks for all the clarifications Gary. I had a Cokin to hand, so I used that, but I could see the negative effects straight away (including a fair amount of warming).
 
I am only running 6.5 FtL at the moment and it is marginal but this still seems acceptable, I think I would run more given the option. Black levels are now truly excellent ;)
 
Can people comment on what colour setting they are running at?

I noticed on another thread that some are running between -10 and -20!

I got the sensor out again to set the colour level of red @ 21% of 100IRE and it was pretty much spot on at 0 (in fact +1 was closest). Is this considered an accurate way of setting?

I know from my CIE chart from measuring the primaries that Red is over saturated, does this mean that this method of setting the colour level becomes inaccurate?

My ND2 filter arrived yesterday, had a quick play with it just manually placing it front of the lens. My initial reaction is that I'm not really sure that I like what I see, I think down to the drop in brightness making the image seem less punchy? May look better after recalibration and some proper film watching...
 
Can people comment on what colour setting they are running at?

I noticed on another thread that some are running between -10 and -20!

I got the sensor out again to set the colour level of red @ 21% of 100IRE and it was pretty much spot on at 0 (in fact +1 was closest). Is this considered an accurate way of setting?

I know from my CIE chart from measuring the primaries that Red is over saturated, does this mean that this method of setting the colour level becomes inaccurate?

IIRC the colour decoding is reasonably accurate. This shouldn't be confused with the colour gamut which is something different and as you know is way oversaturated. Using the colour setting is an attempt to mitigate the oversaturated colour by making the PJ colour even less accurate but less vivid and maybe more pleasing.

You can use the accupel (www.accupel.com - under the 4000 manual section) display calibration app to calculate target Y for non standard gamuts.

AVI
 
At 21% my projector is at -12 on the colour setting

Although the primarys and secondarys are out ( no CMS) I find the colours fine TBO

The rgbs are on target for the greyscale all deltaEs below 3
 
Question for a HD1 owner....

With a power cable and HDMI connected and the projector pushed as close to the rear wall as possible what is the distance from rear wall to front of the lens?
 
Question for a HD1 owner....

With a power cable and HDMI connected and the projector pushed as close to the rear wall as possible what is the distance from rear wall to front of the lens?

On mine it's 490mm - that's using a pretty flexible HDMI cable and NOT the standard power lead (although there's nothing special at all about mine - it's just a computer one with the plug chopped off).
You could squeeze it another 10mm or so closer if you installed a right-angle HDMI connector or something. There aren't any vents at the back, so there's no reason to keep any distance.
There might be some right-angled kettle leads available too - worth investigating if every mm counts.

hth
tt
 
Something worth noting is that the HDMI sockets are upside down, so some of these right-angled connectors will turn the cable towards the top surface of the projector. Which I guess isn't ideal. I haven't found if any turn the other way.

Edit - just seen an IXOS one which turns sideways, but is £15!
 
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Thanks for that - every mm does count with the short throw I have to work with. Unfortuntely the HDMI and Power cables are buried in the wall so the right angled option is out but thanks for the tip.:)
 
Sorry to bump up this thread.....

I am no novice in the basic 'theory' of AV entertainemnt but at the same time my knowledge isnt that deep, so sorry if my questiosn appear a bit wierd!

I have had my HD1 fitted about 18 months now and been impressed with the PQ though the bulb life is rather low for various reasons...

Anyway recently bought the Oppo and there has been discussion about 1:1 mapping with both flat screens and projectors.

Obviously I can see my PJ is accepting/receiving a 1080P but would like to know if my PJ is set to 1:1 mapping, or over/underscan?

Depending on my sources (V+, Arcam DV139, Oppo 83, HTPC) the picture seems to vary slightly in both size and placement on the screen - so any advice comments would be appreciated.

Also, what settings are people using? to be honest, playing witht he calibration discs when I first got my PJ, the picture didnt really need to appear to need tweaking.

Adrian
 

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