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Spyder2

As I have mentioned in a previous posting, I use the Spyder2 sensor with the HCFR software for colour calibration.

The Spyder2 isn’t actually intended for use with front projection systems, but in practice it works quite well. The first hurdle is tripod mounting the sensor which doesn’t come with a screw hole for the tripod. In the past I’ve used a little painters tape to hold it on.

While this works fine, I’d much rather be able to screw it onto the tripod mount like I do my camera. It turns out that a standard 1/4″-20 nut will work just fine for this purpose, that an a little glue gives me a nice way to tripod mount the sensor.

There is a removable filter on the Spyder2, the documentation recommends using the filter for LCD displays (flat panel/computer monitors). In the past for CRT projector calibration I’ve removed it and aimed the sensor at the screen to record the reflected light. For my current LCD projector I’ve been leaving the filter on.

Tonight I experimented with the filter on, and off. With surprising results. I am using HCFR in its LCD mode, but I would have thought that would have minimal impact on the readings.

Filter On

Filter Off

These readings are based on a 70 IRE gray screen, all I did was swap the filter on and off. The filter on measurement matches what I was seeing on screen, a mostly balanced gray.

From my experiments, there seems to be some minor variation in readings based on the angle of the sensor relative to screen surface, but only a few percentages. When pointing the sensor at the projector there is more variation, but it didn’t seem to be radically different.

When reflected from the screen, I have the projector ceiling mounted and the sensor pointing at an angle up toward the center of the screen. You can get a sense of what I mean by the first picture in this posting. When gather data on having the sensor pointed at the projector, I mounted it a few feet out from the screen, approximately centered and as perpendicular to the incoming light as I could manage by eye.

Here is the CIE diagram based on readings from the screen.

And here is the CIE diagram with the sensor pointing at the projector.

The CIE diagrams look nearly identical. Things get more interesting when we look at the RGB levels and delta E.

Here is the RGB levels as read from the screen.

And now RGB with the sensor pointing at the projector.

By pointing at the projector, I’m able to get more sane looking reading down to 20IRE, whereas the reflected from the screen readings are only sane to 30IRE.

However, the delta E values are quite a bit higher when pointing at the projector. This may be due to higher variation in the readings due to the angle vis-a-vis the projector or that we are not taking into account the effect of the screen. It almost seems we are trading off accuracy for better low IRE response.

In conclusion:

I’d highly recommend gluing a nut onto your Spyder2 sensor, it makes mounting it on a tripod really easy.
Filter on seems to be the way to go, but I’d like to understand why I got such whacky readings with it off.
Reflected off the screen seems to be the best solution for getting readings.

HDMI Cables

HDMI has been around since late 2002, but until about 2006 it was a total non issue for most folk and I’d consider it still in the fairly early adopter stage. Easy for me to say, I’ve got an HDMI video chain now.

If you are considering a new TV / Display then HDMI should factor in to your decision, but don’t buy into any of the sales pitch on deep colour etc. The real benefit to HDMI is that it is a digital connection between your source (DVD Player) and the display (TV). The content it carries is the same (for the most part), but keeping it in the digital domain is a real benefit.

Most of the cable makers are taking people to the cleaners. FutureShop’s cheapest HDMI cable is $49.99. If you want to stick to a big brand name, the Monster cables start at $83.99 up to $156.99 for a 1M cable. What is shocking here, is that almost all of the cables come from the same small set of factories in China – you really are paying extra for the name brand.

From my research and reading, assuming a reasonable level of quality in the cable construction, up to 5M you don’t need to worry about the bandwidth capabilities of the cable. Even the cheap cables will handle 1080p and beyond. Additionally, as most consumer equipment is only just starting to pass 1080p there is no reason to support more than that – with the one exception of cables that are run in the walls. For a 1M cable, you don’t need to spend a lot, and you can buy in wall rated cables relatively cheaply as I did.

My choice was to go with Blue Jeans Cable, specifically I bought their Tartan line of cables. Let’s take a look at what came in the mail:

So for my setup, I needed two 15foot cables. One HDMI/HDMI for my new Oppo 980 DVD player, so I got the slightly more expensive 24AWG cable for $15.75. The second cable is for my Starchoice DSR 505 for which I needed DVI/HDMI, since the best I can get out of this box is 720p/1080i I chose the less expensive 28AWG for $6.00. Yup, six dollars, and it will very likely support 1080p over that distance.

Here you can see them plugged into my projector:

The 24AWG cable jacket is bigger than the power cord. I strongly suspect that the FutureShop cables are 28AWG at best, very likely a smaller gauge. Oh yeah, and shipping was $5.75 – so I still came out way ahead.

The cables work great, no issues at all. In summary, yes HDMI is a good option to have but don’t pay an arm and a leg for the cables.

1080UB Colour Calibration

Tonight I spent a few hours tinkering with the colour management system and setting the grayscale. I’m quite pleased with the results. I’m still just under the 10H mark, so as the bulb ages a little, I do expect this will change.

For details on my setup and measurement process – check out the recent post on colour measurements.

This is my first attempt at doing a calibration on a digital projector, my past experience has been with CRT projectors which have used analog controls. The ability to have memories and recall alternate settings is very nice. This lets you experiment with abandon, as well as perform simple A/B comparisons of before and after.

Some of the feedback I saw on the AVSForum was that some folk had started to use the settings suggested in the projectorreviews.com write up on the 1080UB. Specifically, it was suggested that Theater Black 1, modified in the following manner:

Theatre Black 1, 6500K color temp, Offsets: Red – 2, Green 0, Blue 3. Gain: Red 2, Green 3, Blue 0. For viewing I normally had the Skin Tone setting at 3, or occasionally at 4. – Art Feierman

Now I may have missed something, but I didn’t see a description of adjusting the primary or secondary colours – which from my first set of measurements are clearly not right for REC601 (they may be closer to REC 709 for HDTV images).

However, there are several comments about eye-popping colour in the review – I can’t help but wonder if this is due to the not quite correct red and green. There is a disturbing trend in new displays supporting a larger colour gamut, and using it to differentiate themselves from other displays by using a non-standard (non-accurate) colour mapping.

Using Theater Black 1, I also noticed that both the blacks and the whites were crushed. This may have something to do with my signal path, but this is contrary to my observations with Theater Black 2 which seemed right on.

One DVD I’ve seen referenced in some reviews is The Thomas Crown Affair. The skin tones in this apparently show off the colour accuracy of a display. Having the ability to A/B my before and after made it very clear when looking at shots of Pierce Brosnan, pre-calibration he appeared a little sun burnt and post he looked much more natural. My initial impression is that colours seem a bit more muted than the default, but the image is still very engaging – and the Thomas Crown Affair completely sold me on the post-calibration setting being much more correct.

This was more a learning experience. I’m still running in a very temporary mode with some cheap component cables and my old Sony player. The Oppo 980 arrived this week, but I’m still waiting on the HDMI cables before I can get it setup.

Folks interested in my actual settings and some pretty pictures, read on..

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