My Epson 4900 Starved to Death

4900-head-errorWhen I turned on my Epson Stylus Pro 4900 a few days ago to do the regular maintenance cycle, the dreaded fatal error 1A39 appeared on the LCD. Kudos to Epson for these descriptive error messages. Not.

A quick search on the net as well as phoning the service and I had a complete diagnosis: the print head went dead. Replacement (including the pump unit) would cost about 80% of a new printer. Oops.

This is the fourth occurrence of such a problem in my circles. The urban legend says that when left turned off for a while, ink dries up from the head and since it is also used for cooling, being inkless repeatedly (no cooling at startup) will fry something in the head assembly. This seems to affect Epson’s current TFP heads (used in the 4900/7900/9900 – those models me and my acquaintances had issues with). The legend also tells that in newer heads (the ones that you get if you go the replacement route or buy a x900 printer these days) had been redesigned and free of this problem.

This theory is somewhat supported by the fact that most of the printers having this problem were used sporadically. I had no issues with the 4900 during the 3 years I used it heavily, but during the last one and a half years it had been sitting mostly idle, only doing a small print every two to four weeks.

In other words, it’s been starved to death.

Since my printer already made much more profit than it’s cost, I’m just mildly irritated. But saying that it’s not irritating to run into a design flaw (in case the legend holds true) that costs me money would be a lie.

Anyway, I’ll need a new printer. My use in the future will continue to be light, so I’m not going the TFP route again. Yes, the legend says that this problem had been fixed in the new heads, but Epson also publicly stated several times that new printers are not susceptible to clogging – which was far from truth with the 4900. So no TFP, thank you.

I’m looking into two printers now: the 17″ Epson P800 (which uses the previous generation AMC head), and Canon’s 24″ iPF6450 PRO 2000. The 17″ PRO 1000 had been quickly ruled out by not having a straight paper path, not supporting some heavy media I use, and it’s ridiculous margin handling (I can’t print a 30×45 on an A3+ paper). Epson’s new P7000 was considered for a fleeting moment, but it uses a TFP head, so I stopped thinking about it.

Fortunately I’m not in a hurry to get a printer immediately, so I’ll have time to do some evaluation before making the decision. I’ll start with a first look on the P800 towards the end of next week.

But there’s a gift in every problem: since the only thing I used Windows for was printing, I could finally eliminate the very last (albeit virtual) Windows machine in the company! And man, this is a huge time saver. Based on this, I’ll take the opportunity to reimplement my printing workflow purely on OS X. I badly needed this, but there were always more excuses important things. Now I ran out of them.

Postscript: I’m selling the remaining consumables (inks, cutter blade, maintenance tank) as well as fully operational parts (roll spindle, roll unit, paper tray, or any other parts you may need) from the dead printer. Please let me know if you are interested.

Practical Limits of Enlargeability

I have been asked numerous times about how big a print can be made from a digital image. Up until recently, the answer was quite easy: one would need a 200 PPI or higher resolution image for matte papers and 210 PPI or higher for semigloss surfaces. Canvas is a much more forgiving medium, one could go much lower with careful processing. My biggest enlargement, from a 4.5 megapixel original, was printed on Hahnemühle FineArt Canvas in 36 x 100 cm size. This was shot with an 1D Mark II, so this is a 35x enlargement. The print was made at 90 PPI. Yes, this was a result of several hours of careful editing and a matching media choice.

This is a crop from a 8MP image. The biggest print that still looks great is 38×100 cm. But this is an exception in enlargeability, not the norm. Subject matter really helps here.

Of course high resolution is a must for hyper-realistic prints. Posters can be made at much lower resolutions. But I’m not interested in making posters at all. I even wrote an app (PrintCalc), that can calculate all this resolution requirement stuff for you.

To put it another way, digital prints were limited by the sensor’s resolution.

In these days, however, we face another limits. Diffraction, depth of field and lens quality. Let’s take a Canon 5D Mark III for example. The full frame sensor at 22MP starts to get diffraction limited below f/10. The 7D at 18MP is visibly diffraction limited at f/8. The problem is worsened if you want big prints. One often overlooked attribute of depth of field is that it gets shallower as you make bigger enlargements. But you can’t stop down to increase depth of field at your will, because diffraction kicks in. This might, or might not be a problem depending on subject matter.

For landscapes, diffraction puts an upper limit to practical enlargement ratio. You can only go larger if you use a bigger sensor. For other subjects, where you can shoot at wide apertures, this isn’t that big of a problem, so you are limited by the number of pixels. Speaking of the number of pixels: DxO’s new “perceptual megapixels” ranking is a good indicator what kind of resolution a lens can give you. You can increase sensor resolution, but the lens will still be a limiting factor. Think about this perceptual megapixel number as the one you can use as the basis of maximum print size calculations. Look at the best lest they tested to date: Canon’s EF 300mm f/2.8L IS II USM. It can fully utilize a 21MP sensor, but you’ll end up around 14MP on a 18MP APS-C sensor (the 7D).

So it’s easy to see that blindly increasing sensor resolution in any given format above lens capabilities and so much that is severely affects usable apertures is not the smartest thing.

What is that practical limit? I found that about 20 times enlargements (in linear dimensions) make great hyper-realistic prints, keeping ill-effects at a minimum. This translates to about 50 x 75 cm (20 x 30″) for full frame and 30 x 45 cm (12 x 18″) for APS-C. Regardless of megapixels. Of course you’ll need to hit the 200-210 PPI minimum, which is about 11-12 MP for APS-C and 23-24 MP for full frame. But increasing the sensor’s resolution beyond these points will only allow to reap the benefits of oversampling, and not really allow bigger prints at the same quality (not to mention increased storage requirements).

Want bigger? There’s only one way with today’s technology: increasing sensor surface. Basically we have to paths in pursuing bigger recording area:

  • Go medium format. Digital 645 will give you images that can be printed at 80 x 110 cm (30 x 40″) – from an 50 MP or larger file. This costs a lot.
  • Stitch several images together. I routinely use my TS-E 24mm lens to get images equivalent in size to a medium format sensor (36 x 48 mm). This is more work, but at the fraction of the cost of medium format.

20x enlargements are far better than you could achieve (in high quality) from film. This is actually at least one format size better (full frame 35mm beating 645). But remember that every technology has practical usage limits, and make them work for you – don’t blindly believe manufacturers’ marketing stuff.

Why ColorBase?

After my recent post about the new ColorBase version, a friend asked the question: “why is it better than factory calibration?” I though this could be interesting to other people, so here’s my (longish) answer.

Some background first. In the grand scheme of things, building a color profile for a device is a two-step process. The first step is calibration, which sets the basic operating parameters of the device to a well known (sometimes standardized) default. In case of monitors, calibration sets the black level, white luminance, color temperature and tone reproduction curve. In case of printers, it sets the relationship between color values and the actual amount of ink laid down to be linear – this is why this step is called linearization. The second step is the actual profiling. Here the software determines the color reproduction characteristics of the device and creates the profile.

On the low end, manufacturers tend to skip the calibration step, doing only the profiling. This is a nasty trick and the reason why I think that cheap colorimeter packages that can’t do the calibration step are downright dangerous and actually worth nothing. On the high end profile making is always preceded by calibration.

Speaking of printers: the lack of calibration (linearization) is less noticeable here, because profiling packages do a linearization step under the hood before starting to build the profile. This is not that accurate as the separate step, however (“true” linearization controls parameters in the rasterization process, whereas “simulated” plays with the color values). So basically it is more or less done for printer profiles.

My favorite example for showing color reproduction differences across devices is the TV department of your favorite electronics store. Almost every single one displays the same content differently. Consumer printers are the same. Take two Epson 2880s, and they will print different colors. In case of professional Epsons, all the devices are “factory calibrated” to be as identical as possible when they leave the factory. But this does not mean that they will not drift over time! And because of this drift (and inherent difference in consumer models) you’ll have to re-create all the profiles from time to time. Which could be a daunting task.

To be able to decide whether your device drifted out of tolerances, high end profiling packages provide a validation tool that measures the color reproduction accuracy of the calibrated/profiled device. This way you can check the status periodically and recalibrate/re-profile as needed – instead of doing this blindly every month or so.

Epson’s ColorBase is a software for both linearizing the printer driver and a validation tool for checking the linearization accuracy. A welcome extra is that it can do this for higher-end consumer printers. So one can utilize ColorBase in two different ways:

  • Use it to measure accuracy, and redo the complete linearization/profiling for each of the papers when the accuracy has drifted. This could still be daunting for several papers, but this provides the utmost precision.
  • Use it to measure accuracy, but only redo the linearization if the printer became out-of-spec. Because ColorBase returns the printer to the state it had been before creating the profiles, there are pretty good chances that the profiles will remain accurate.

I have been using the second method for five years with great success. And the longest period that the printer was in-spec reached 2 years with my late 4800. This demonstrates that we are talking more about peace of mind and process control here than visible results. This stuff is about to catch when something goes wrong before it ruins several prints.

And what’s the difference between factory calibration and ColorBase? Actually they are two different things. Factory calibration is for making sure that pro printers are identical when they leave the assembly line, whereas ColorBase is a tool for employing process control.

I must mention two glaring omissions in the package, however. Ink limiting and support for third party papers. You can control ink within the printer driver to some extent, but this should be done with the linearization step. Over-inking could be a serious problem using the driver with some papers. Not supporting third party papers could be worked around by linearizing the printer to the Epson paper selected as the media type for the third party paper (for example Velvet Fine Art in case of Hahnemühle Photo Rag). You will not have a linearization for Photo Rag (which would be the desirable), but at least you’ll be able to build its profile on a solid and consistent base.

If you need ink limiting and linearization for custom papers then moving to a RIP is the only solution these days.