Friday, December 31, 2021
Thursday, December 30, 2021
My, my; it's been eighteen months since I paid any attention to this blog. Possibly the longest quiet period since I started writing it in 2003! Anyway - it's mostly down to work (I started Media Engineers at the start of 2020; a few weeks before the pandemic started).
Back in 2019 I was approached by ASUS to point a probe at their new PA32U (the first of their 32" monitors to carry the ProArt product name). It had a lot of issues and I wrote up my findings here. I also made a video showing my LightSpace profiling.
- Rec.709 with a gamma of 2.2
- Rec.709 with a gamma of 2.4
- HLG - Rec.2020 colourspace with HLG 1.2
- DolbyVision - ST.2084 curve
- It's a single-layer IPS (LCD) display with an LED backlight,
- It's a FALD (so zone'd backlight) - like the Apple XDR it's an effort to make an LCD have a higher dynamic range. A typical 10-bit LCD panel (like an Eizo CG319X) can achieve about 1,000:1 but with a zone'd backlight that can be in excess of 1,000,000:1 but with the downside of halation around edges and transitions. Compared to dual IPS (think Eizo CG3146 or Sony HX-310) or OLED (typ. Sony X300) it's poor-man's HDR.
- They sell it on the strength of it having "quantum dots"(!) yet it can achieve about the same percentage of DCI-P3 colour space as a modern non-quantum LCD or OLED. If QD actually exists then surely it should approach laser-projector like primary colours and so get close to Rec.2020 colour primaries? Non-intuitively you need monochromatic primaries to be able to get the largest colour-triangle and that's the promise of Quantum Dots - but since this panel does not have monochromatic primaries where are the quantum effects?!
- If you put it into HDR mode, then switch the i/p to an SDR signal, disconnect/re-connect (which you have to do) it will then let you recall one of the SDR USER settings (so 1 for 2.4 gamma, 2 for 2.2 gamma) BUT it never takes the backlight back down to SDR levels - so you get rec709 with 500Cd/m2 white. You have to manually wind the "Brightness" figure back from 100 to 10
- "Brightness" is mislabelled - it should be "Backlight" or somesuch
- Brightness is actually called "Black Level"
- Their software proved useless - without ColourSpace I would have been left high and dry.
- All this fiddling about took days (whilst I was doing other things) - I would not want to have been faced with this at a client's site. I won't be taking bookings to calibrate these monitors.
Wednesday, August 05, 2020
- Spectroradiometers measure wide band light energy - everything from 380nm (or lower) - very deep blue through to 740 (or higher) - very deep red. They are slow to make a reading (many seconds) and do not cope well with low light levels.
- Colourimeters measure just three wavelengths (just like your eyes) - which we'll typically refer to as Red, Green and Blue (but really are X, Y, Z colour matching functions) and so are vulnerable to metameristic failure (a mismatch between the primary colours generated by the display device and the filters used in the colourimeter) BUT they are fast (my Klein K10A can make a read in less than a second) and they are accurate all the way down to near-black.
- Have the probe as close to the screen as possible,
- Have the projector in High LD power mode for at least half an hour,
- Have the video input set for full-range video,
Sunday, May 10, 2020
- PockEthernet is a tester for ethernet and IP networks. Serious network people use a Fluke DTX-1800 (I used to have access to one) - it's now discontinued, but like the replacement DSX-series all TDRs (Time Domain Reflectometers) are expensive (a few thousand pounds) but if you want to certify an install it is expected. At the other end of the spectrum you have the £50 DC testers that just make sure there is continuity on each of the eight legs and really just allow you to have some certainty in termination polarity etc. The PockEthernet is a half-way house with some TDR capability (not sure home accurate is it) but nice record keeping. Above a little DC-tester (like a ModTap or others) it can do some IP testing; POE, DHCP, VLAN tags etc. and so for me is ideal.
- BeeLine bike navigator - I often see folks with their smart 'phone in a waterproof wallet as a bike GPS. That's great, but when I'm cycling somewhere I'm not entirely familiar with I often like to find my way but certain in the knowledge that as I get closer I can make better navigation decisions. The BeeLine is a bluetooth attached smart compass that tells you what direction to go and how far your destination is. I've been using mine for maybe eighteen months and it works really well. It is stable and accurate with good battery life.
- Pebble Smart Watch - Although the Apple Watch is undoubtedly a miracle to technology I never felt it was for me; the biggest problem is the battery life; two days at best. It also seems to need a lot of curation. Friends who use them are constantly attending to them and I only really wanted a second screen for my 'phone with good notifications, health tracking and control of media players. The Pebble does just those things really well and nothing else. The battery on mine (Pebble Time Steel variant) lasts for more than a week and when they went bust at the end of 2016 I bought a second one just in case. They charge in about an hour.
- Oscilloscope Watch - I know what you're thinking; what a daft idea! I've written a lot about this one in the past because I did get a very janky alpha-version (3D printed case, very early build of the software etc). Still, five years on and the project is still live on Kickstarter and so we live in hope!
Thursday, March 12, 2020
- Cheap, low air volume fans
- Tiny holes in the chassis through which to try and pull enough air
- No control of the fans even though the ones they supply have a tach output
Friday, November 29, 2019
- Download Ultrascope for your particular series (so DS1000E in my case)
- Download the Windows driver (had to find this on the Way Back Machine!), Extract these two files, then go find the device in the Device Manager. Update the driver and point it to the directory where you extract the driver files.
- Next, download the NI-VISA Run-Time Engine (v5.0.3 as of this writing). Beware, this file weighs in at 71 MB. Install the VISA runtime with the default options (you could probably get away with just installing the USB portion, but I didn’t try it).
- When the NI-VISA installer finally finishes, you might be prompted to reboot. I skipped this step :-). Run the Ultrascope software, and click on Tools –> Connect to Oscilloscope. I was prompted with a list of devices, with none of it making much sense, except the first option “USB0…”