Canon Powershot Zoom review

DNP D820A review

A very solid and trouble-free printer that makes excellent prints, including spectacular panoramics, for a significant fixed price.

Despite striving for the paperless office, and believing photographic prints are mostly a relic, I have a substantial collection of printers (as my daughter points out, it’s 5 printers per person in my household):

  • HP OfficeJet Pro X551dw (extremely fast using PageWide fixed head technology, quite economical, huge paper tray capacity, very bulky)
  • Epson EcoTank ET-16600 (prints and scans A3, very economical, also very bulky but not considering the print size)
  • Brother QL-700, QL-820NWB, QL-1110NWB label printers (can make labels any length you want, the latter two are AirPrint compatible)
  • Rollo label printer (will take practically any label stock you can throw at it)
  • Fuji Instax SP100 instant photo printer (kids love them)
  • Canon Selphy QX10 portable dye-sub sticker printer for my daughter
  • two Dai-Nippon Printing DNP DS820A 8" dye-sub printers, one in storage
  • An Epson Stylus Photo R2400 in storage
  • a couple of Brother TZe label makers
  • a Dymo LabelWriter 450 Twin Turbo (unreliable garbage, at least on Mac, avoid)
  • A Selpic P1 on the way
  • A Prusa i3 MK3S 3D printer (not sure if that counts)

The DNP DS820A replaced my Epson R2400 for two reasons:

  • I print seldom enough that inks clogging in the nozzles was a big issue.
  • The Epson is a behemoth that is very hard to find a place for, even before I downsized.

The DNP uses dye-sublimation technology to make its prints. You may have encountered one at a drugstore self-service photo kiosk, or at photo events like Macy’s Santa Claus portrait sessions. These printers are designed specifically for these two use cases, and are built like tanks with a steel chassis. Since most events typically gang two or even four printers to maximize throughput, they are also very compact, with a footprint barely larger than an A3 sheet of paper, mine is on a lower shelf in my IKEA FREDDE computer desk.

Until the advent of fine-art photo printers with 6 or more color pigment inks, dye-sub was the top-end digital photo printing technology, thanks to the continous tones it can generate, like photographic processes (e.g. Fuji Frontier or Noritsu QSS digital minilabs, or large-format laser enlargers like the Cymbolic Sciences LightJet or Durst Lambda/Theta). Dye-subs have all but disappeared from the consumer market, however, apart from some Canon Selphy compact printers, and are now largely reserved for professional applications, with a price to match. The DNP DS820A used to cost $1100. They lowered the price to under $1000 a few years ago, but cheaped out by removing the print-catching basket that used to be included in the older package.

You pop off the front panel and install a roll of paper and a reel of dye ribbons in a tray above the paper inside the printer, then pop the front back in. Nothing protrudes and the media is protected from dust, which is really nice. There are two different sizes of media, 8x10 (130 prints) and 8x12 (110 prints). The size is mostly relevant for the dye ribbons that have CMY sections sized in increments of 10 or 12 inches, but a surprising consequence of this is that you cannot switch from 8x10 to 8x12 and vice versa (you can make smaller divisions and the printer will trim them to size using its built-in cutter). The cost per print is about $0.65 for 8x10, $0.80 for 8x12, $1.30 if you get the premium metallic paper. Since the paper and ribbon is consumed no matter the coverage, it’s a constant, unlike the variable costs of an inkjet printer.

The print quality is excellent, as can be expected, as is the color calibration out of the box. It may not quite have the tonal subtlety of an Epson, but there is no visible pixellation. Furthermore, the prints get a clear protective laminate, which makes them smudge-proof and very tough. You can even choose one of four different finishes applied by a roller so no media change required: glossy, luster, matte and fine matte.

One of the marquee features of the DS820A and its little 6" brother the DS620A is the ability to make panoramic prints. Each print is made by combining multiple pages together, with about 2" of overlap wastage, so if your printer is loaded with 8x12 media you can make 8x22 or 8x32 prints, with 8x10 media you can make 8x18 or 8x26. The 8x32 panoramic prints are absolutely spectacular, although finding a suitable frame for them is not a trivial undertaking, that not being a standard print size.

Unfortunately this functionality is not built into the printer driver, but you must use the DNP Hot Folder utility, and while it is available for both Mac and Windows, only the Windows version can make panoramic prints. DNP Hot Folder is meant to use for events where a single PC or server controls multiple printers. You drop the files into a directory per print size (hence the name “Hot Folder”) and the software will automatically print it on the next available printer loaded with the right media. Since the printers run in parallel, even if the print speed is not incredibly fast (about 30 to 60 seconds per print), aggregate throughput is sufficient for a busy event. I have mine on a USB switch (the printer has no network connectivity) to share it between my Mac and my gaming PC.

Virtual Reality for the people

I have been shooting stitched panoramas for almost 20 years. I have used manual panorama heads like the Kaidan Kiwi+ and more recently the pocketPANO Compact, robotic heads like the Gigapan EPIC 100, and four successive generations of the Ricoh Theta (Theta, Theta S, Theta V, Theta Z1).

Setting up and iterating a manual head is incredibly tedious. The Gigapan makes it less so, specially when using long lenses (my standard setup is a Leica M typ 240 or M10 with a 90mm f/2 Apo-Summicron-M ASPH). The Theta series was a major breakthrough in that it could produce nearly seamless 360° panoramas with no motion artifacts or ghosting. The Z1 with its large 1″ sensor finally yields image quality that I am happy with.

The viewing situation has also improved. In the early days you needed Java applets or dubious plug-ins. Nowadays, it can all be done in HTML5 with the aid of JavaScript libraries like Panellum. The user experience is still one of scrolling an image through a rectangular viewport in browser window. The experience on mobile is a bit better because it can use the accelerometer so you scroll by panning with your phone or tablet. It’s still not a fully immersive experience.

This Friday Facebook announced a price drop for its Oculus Go VR headset, the entry-level 32GB model being at a near-impulse purchase price of $150, and of course I yielded to the impulse. I had bought the original Oculus Rift to get a sense of what the potential of VR was, but tethered to a beefy PC, it made for impressive demos but not much more.

The Oculus Go changes this completely because it is standalone (it has the guts of a midrange smartphone circa 2018) and affordable. One of the ways they kept costs down is by removing motion tracking: it can detect angular motions of your head, but not when you are walking around, but for purposes of viewing 360° panoramic stills and videos, that is not required.

One of my concerns was how deeply it would be tied to the Facebook privacy-mangling machine. My New Year’s resolution for 2019 was to delete my FB account (my 2020 resolution was to switch all my digital camera clocks to UTC and never again bother with the abomination that is Daylight Saving Time)—underpromise and overdeliver, that’s my motto… Any requirement to have a FB account would be a total deal-breaker for me.

The second concern was how much of a hassle it would be to set up and use with my own photos. Camera-makers are not known for outstanding software and Ricoh is no exception. There is an Oculus third-party app for Theta cameras, but it hasn’t been updated in ages and only lists Theta S compatibility.

I was pleasantly surprised at how smoothly it went. You can avoid the FB account by using an Oculus account (I used mine from the Rift), and no additional apps are required. Just install the Android File Transfer utility if you are on a Mac, copy the files to the headset’s Pictures directory. I would recommend using subfolders because the built-in Gallery app is not smart about caching thumbnails and is very slow at regenerating the view if there are more than about 20 images or so in a folder.

The image quality is not exceptional. Mike Abrash, who worked on the ground-breaking 3D game Quake, and is now Chief Scientist at Oculus, says fully immersive VR requires resolution halfway between 4K and 8K in each eye (vs. 2.5K shared for both eyes on the Go), and is at least a decade away. The immersive nature of the Go does provide that elusive Wow! factor, however, and more than makes up for its designed-to-a-budget shortcomings. The 2560×1440 display with an apparent field of view of 100° yields 3.7MP in the FOV but spherical trigonometry calculations reveal the entire 360° sphere would require a 26MP image to cover it entirely, which is slightly more than the 23MP images the Theta Z1 delivers. Fully immersive VR requires very high resolutions!

It even handles video transparently (you do have to convert Theta videos from the native format to equirectangular projection video with Ricoh’s app, which is excruciatingly slow). Keep in mind that video sizes are large, and with a 32GB model, there are limits to how much you can store on the device. If you plan to view immersive videos, the 64GB model is highly recommended.

The Oculus Go also has a “Cast” feature that will stream what the person wearing the headset is seeing to the phone it is paired with. You can have a friend wear the headset and narrate what they are seeing, I tried this with my architect mother-in-law as I was showing her the sights in Jerusalem, much to her delight (her master’s thesis at SOAS was on the Dome of the Rock). The Go has a unique sound projector developed by Oculus that means the user doesn’t have to wear earbuds, and can hear you speak. I would recommend you change the default display sleep time from the ridiculously short 15 seconds to 3 to 5 minutes, so you can swap the headeet without losing the cast session or resetting the app. Sadly, the battery life is nothing to write home about. I would guesstimate it at 1 to 2 hours, tops.

I still need to figure how to share my 360° VR photos using WebVR so other people can view them from their own Oculus Go (or other headsets).

One essential accessory for the Z1 or another similar 360° camera is a selfie stick or similar implement, otherwise your hands will appear prominently in the final panorama. Ricoh sells three models.

The TM-1 is a very well designed tripod (rumored to be made by Velbon) with a magnetic quick-release mount. It’s easy to deploy with one click, unlike a conventional tripod, and fully extended the camera is at eye height for a natural perspective.

The TM-3 is a short telescopic stick. It’s long enough that your hands no longer appear in the picture but low-profile enoough that the TM-3 itself is invisible. It is well-made, unlike most generic Chinese selfie sticks, unlocks and locks with a simple twist, and the TS-2 case for the Z1 has an opening at the bottom so you don’t need to detach it before putting the camera back in its case, a nice touch.

The TM-2 is a longer version of the TM-3 with an unnecessary swivel head, I haven’t tried it but the swivel head would defeat the invisible factor.

How big can a panorama get?

I use the Kolor AutoPano Giga panorama-stitching software, recently acquired by GoPro, but I have yet to produce a gigapixel panorama like those they pioneered. This brings up an interesting question: given a camera and lens, what would the pixel size of the largest 360° stitched panorama be?

Wikipedia to the rescue: using the formula for the solid angle of a pyramid, the full panorama size of a camera with m megapixels on a sensor of a x b using a focal length of f would be:

m * π / arctan(ab / 2f / sqrt(4f2 + a2 + b2))

For single-strip panoramas of height h (usually a or b), the formula would be:

m * π * h / 2f / arctan(ab / 2f / sqrt(4f2 + a2 + b2))

(this applies only to rectilinear lenses, not fisheyes or other exotics).

Here is a little JavaScript calculator to apply the formula (defaults are for the Sony RX1RII, the highest resolution camera I own):

mm actual 35mm equivalent


The only way I can break through the gigapixel barrier with a prime lens is using my 24MP APS-C Fuji X-T2 with a 90mm lens.

Update (2020-01-21):

Now I could reach 171 gigapixels with my Nikon Z7 and the Nikkor 500mm f/5.6 PF.

Update (2021-01-30):

There was an error in the JavaScript that implements the calculator, it used 4f instead of 4f2, and for telephoto focal lengths, the difference is dramatic. Thanks to users ZS360 and GerladDXB at DPReview for pointing out my error.

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.