Scanner group test

TL:DR Avoid scanners with Contact Image Sensors if you care at all about color fidelity.

Vermeer it is not

After my abortive trial of the Colortrac SmartLF Scan, I did a comparative test of scanning one of my daughter’s A3-sized drawings on a number of scanners I had handy.

Scanner Sensor Scan
Colortrac SmartLF Scan CIS ScanLF.jpg
Epson Perfection Photo V500 Photo (manually stitched) CCD Epson_V500.jpeg
Epson Perfection V19 (manually stitched) CIS Epson_V19.jpg
Fujitsu ScanSnap S1500M (using a carrier sheet and the built-in stitching) CCD S1500M_carriersheet.jpg
Fujitsu ScanSnap SV600 CCD SV600.jpg
Fuji X-Pro2 with XF 35mm f/1.4 lens, mounted on a Kaiser RS2 XA copy stand with IKEA KVART 3-spot floor lamp (CCT 2800K, a mediocre 82 CRI as measured with my UPRtek CV600) CMOS X-Pro2.jpg

I was shocked by the wide variance in the results, as was my wife. This is most obvious in the orange flower on the right.


I scanned a swatch of the orange using a Nix Pro Color Sensor (it’s the orange square in the upper right corner of each scan in the comparison above). When viewed on my freshly calibrated NEC PA302W SpectraView II monitor, the Epson V500 scan is closest, followed by the ScanSnap SV600.

The two scanners using Contact Image Sensor (CIS) technology yielded dismal results. CIS are used in low-end scanners, and they have the benefit of low power usage, which is why the only USB bus-powered scanners available are all CIS models. CIS sensors begat the CMOS sensors used by the vast majority of digital cameras today, superseding CCDs in that application, I would not have expected such a gap in quality.

The digital camera scan was also quite disappointing. I blame the poor quality of the LEDs in the IKEA KVART three-headed lamp I used (pro tip: avoid IKEA LEDs like the plague, they are uniformly horrendous).

I was pleasantly surprised by the excellent performance of the S1500M document scanner. It is meant to be used for scanning sheaves of documents, not artwork, but Fujitsu did not skimp and used a CCD sensor element, and it shows.

Pro tip: a piece of anti-reflective Museum Glass or equivalent can help with curled originals on the ScanSnap SV600. I got mine from scraps at a framing shop. I can’t see a trace of reflections on the scan, unlike on the copy stand.

Update (2018-10-14):

Even more of a pro tip: a Japanese company named Bird Electron makes a series of accessories for the ScanSnap line, including a dust cover for the SV600 and the hilariously Engrish-named PZ-BP600 Book Repressor, essentially a sheet of 3mm anti-reflection coated acrylic with convenient carry handles. They are readily available on eBay from Japanese sellers.

Avery 22807 template for InDesign

The Avery 22807 2-inch circular stickers are a good alternative to Moo, PSPrint et al when you need a small quantity of stickers in a hurry. Unfortunately Avery has not seen it fit to provide usable InDesign templates as they do with some of their other sticker SKUs, only Microsoft Word, which is needless to say inadequate. A search for “Avery 22807 Indesign template” yielded some, but they have issues with missing linked PDF files.

I reverse-engineered the Microsoft template to build one of my own, with dimensions (including the tricky almost-but-not-quite square grid spaced at 5/8″ horizontally but 7/12″ vertically) to simplify “Step and Repeat…”.

I have only tested this with my InDesign CS6, not sure if it will work with older versions.

Avery 22807 2-inch circular labels.indt

Avoiding counterfeit goods on Amazon: mission impossible?

I mentioned previously that I seldom shop for electronics on any more, preferring B&H Photo whenever possible. I now have another reason: avoiding counterfeit goods.

My company boardroom is in an electromagnetic war zone—dozens of competing WiFi access points combined with electronic interference from the US-101 highway just outside make WiFi reception tenuous at best, and unusable more often than not. To work around this, we set up a wired Ethernet switch, and since most of our staff use MacBook Airs, Apple USB Ethernet adapters purchased from Amazon. When I side-graded from my 15″ Retina MacBook Pro to a much more portable 12″ Retina MacBook, I wasn’t able to connect using the dongle, and the name of the device was interspersed with Chinese characters. At first I thought it was an issue with my Satechi USB-C hub, but I experienced the same problems via a genuine Apple USB-C multiport adapter as well.

Eventually I figured out the Ethernet dongles were counterfeit. The packaging, while very similar to Apple’s, was just a tiny bit off, like amateurish margins between the Apple logo and the edges of the card. On the dongles themselves, the side regulatory disclosures sticker was inset, not flush with the body of the adapter.

Counterfeiting is a major problem. By some accounts, one third of all Sandisk memory cards worldwide are counterfeits. In some cases like chargers or batteries, your equipment could be at risk, or even your very life. The counterfeit adapters we purchased from Amazon did not come from Amazon themselves but from a third-party merchant participating in the Amazon marketplace. To Amazon’s credit, we returned them for a prompt, no questions asked refund even though we bought them over six months ago, but it is hard to believe Amazon is unaware of the problem rather than willfully turning a blind eye to it.

My first reaction was to tell our Office Manager to make sure to buy only from Amazon rather than third-party merchants (pro tip: including “amazon” in your Amazon search terms will do that in most cases). Unfortunately, that may not be enough. Amazon has a “fulfilled by Amazon” program for merchants where you ship your goods to them, and they handle warehousing and fulfillment. These “fulfilled by Amazon” items are also more attractive to Prime members. One option Amazon offers is Stickerless, commingled inventory where the items you send are put into a common bin. Amazon still has the ability to trace the provenance of the item through its inventory management, but for purposes of order fulfillment they will be handled just like Amazon’s own stock. Some categories like groceries and beauty products are excluded, but electronics are not.

The implications are huge: even if the vendor is Amazon itself, you cannot be sure that the item is not counterfeit. All the more reason to buy only from trustworthy, single-vendor sites like B&H, even if shipping is a bit slower.

Chrome and AES-256 security: it’s not me, it’s you

This blog now supports the HTTP/2 protocol, courtesy of nginx 1.9.5 (PDF).

In the process, I was stymied by an “ERR_SPDY_INADEQUATE_TRANSPORT_SECURITY” error from Google Chrome. HTTP/2 mandates TLS de facto, if not in the strict letter of the specification, and it also forbids a number of obsolete or weaker SSL/TLS ciphers to only permit ones that are truly secure. After some considerable digging, I found out the issue is Google Chrome on Mac and Android (presumably Windows as well) does not support 256-bit AES in HTTP/2, and my server was set up to only accept 256-bit encryption (only the best will do for my readers!). The error message was misleading: it’s not the server but Chrome’s crypto which is lacking.

It seems the cryptographers at Google feel 128-bit AES in Galois Counter Mode is good enough, and they did not want to be too far apart from Firefox (which does not support it either, and just fails without even the courtesy of an error message). In contrast, Safari on Yosemite supports AES-256-CBC (not ideal, I know, but that’s also what Chrome supports if HTTP/2 is turned off) and AES-256-GCM on El Capitan and iOS 9. Here are the settings your browser uses:

This is disappointing. AES-256-GCM is supported in hardware on most Intel hardware nowadays (all but lowest-end chips have the AES-NI instructions) and in the ARMv8-A architecture supported by most smartphones and mobile devices today, where the extra CPU load would matter most. I wonder how much of this is driven by Google’s fondness for Dan Bernstein’s ChaCha20+Poly1305 algorithms. Excellent as they may be, they are not implemented in hardware on the most common platforms, nor implemented at all in OpenSSL. It is quite disconcerting that my phone has better crypto than my desktop browser.

I ended up resolving the issue by loosening my cipher list from AES256+EECDH to EECDH+AESGCM:EDH+AESGCM:AES256+EECDH:AES256+EDH, but Chrome really should catch up and not let itself be hobbled by the increasingly irrelevant Firefox and its hoary NSS crypto.

I probably sound harsher than I intended towards the Google crypto team. The backward compatibility issues they have to deal with, from poorly designed TLS standards to broken web server software, intrusive anti-virus or corporate proxy servers mean a lot of their energy goes into exception cases, rather than implementing the latest and greatest in crypto algorithms.

Update (2017-01-18):

It looks like Chrome silently added AES256-GCM support last year, as it now negotiates the ECDHE-RSA-AES256-GCM-SHA384 cipher on

How the iPad Mini killed my iPhone

The single greatest feature of the iPad is the fact it cannot receive phone calls. Despite being a telecoms engineer by training, I despise phones, and it seems the millennial generation shares my disdain, as it favors less intrusive means of communication like texting.

The iPad is an essential device for me. I am on a 2-year upgrade cycle (at best) for phones, a 5-year cycle for my desktop Mac Pro, and have stopped using laptops altogether, but I will get every single iteration of the iPad. Now, even though my jacket has a pocket sized large enough to hold my full-sized iPad, the weight and bulk means I seldom did so, and kept it in my bag, which I rarely take out with me when going out for lunch. When I saw the iPad Mini and how lightweight it was, I bought one and started carrying it with me all the time.

The Mini is not a replacement for my Retina iPad, as my worsening eyesight makes it a strain for sustained reading, which is why I kept my grandfathered unlimited AT&T data plan on the full-sized iPad and got a limited Verizon plan on the Mini.

No, the device that was displaced is actually my iPhone. The iPad Mini weighs barely twice as much, is thinner, fits in my jacket pocket but has a screen 4 times the size while remaining single-hand-holdable, and is actually usable as a web browsing device or eBook reader, unlike the iPhone’s cramped screen. I don’t believe in the 5-inch phablet form factor, which combines the cramped screen of a phone with the the bulk of a tablet, i.e. the worst of both worlds. I find I never use the iPhone as anything else than a dumb phone any more. I consume less than 60 minutes of voice per month, and if my wife and my startup’s co-founder would let me, I would ditch mobile phones altogether.

Alas I am unable to cut the wireless phone tether, but there is no point in my spending $100 a month on an unlimited data plan for my Verizon iPhone 4, so now that my contract ended, I ported my number over to my old unlocked AT&T iPhone 3GS with a prepaid plan from Airvoice (a MVNO that has the cheapest rates I could find online). At $0.10 a minute without any exorbitant cellco taxes or spurious surcharges, I can expect to spend $6 a month, or 94% savings. That more than covers the $20 a month I pay extra for the iPad Mini’s data plan. The only reason I still use an iPhone instead of switching to a dumbphone is the automatic address book synchronization with my Mac and iOS devices.