Instrument Spotlight SpectroDens

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==Ease of Use==
==Ease of Use==
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These folks must have some kind of patent on the idea of an aperture tube that is formed into the edge of the instrument.  The user can always see the patch that is being measured, whether in spot mode or scanning an entire row of colors.  Its hard to describe how simple and intuitive this is.  There is no need to fold down a part of the instrument to engage the measurement or use an aiming aperture when you're covering the patches with the instrument.  You literally just point and click.
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These folks must have some kind of patent on the idea of an aperture tube that is formed into the edge of the instrument.  The user can always see the patch that is being measured, whether in spot mode or scanning an entire row of colors.  It's hard to describe how simple and intuitive this is.  There is no need to fold down a part of the instrument to engage the measurement or use an aiming aperture when you're covering the patches with the instrument.  You literally just point and click.
==Portability==   
==Portability==   

Revision as of 00:09, 22 March 2019

This month's instrument focus is the Techkon SpectroDens pressroom spectrophotometer, written by Pat Herold, manager of CHROMiX technical services.


Technon SpectroDens

Contents

History

The Techkon SpectroDens has been a staple instrument around the pressroom for years. Always a well-thought-of instrument, with a reputation for accuracy and durability, it is a preferred instrument with many consultants in the field. It is now in its fourth iteration. The current model which came out in April, 2017 is the SpectroDens 4.

Technically this instrument falls into the category of a spectrodensitometer rather than a spectrophotometer - the later being an instrument that is used to scan a large number of colored samples. The former primarily measures the visible light spectrum and converts it into density or Lab values for use with printing presses or other industrial settings. It is typically used to measure individual patches. A densitometer supplies density readings - very useful in the traditional pressroom. A spectrodensitometer measures the spectral bands of visible light, and calculates density from that - a very accurate method with several advantages. Of course, using a spectrodensitometer to get density readings is sort of like using a vise to crack nuts: It's capable of so much more! Spectral readings view all the light that the human eye can see, so there are many applications for human perception, and the device can return colorimetric data such as Lab values, as I have written about in this newsletter.

Example of SpectroDens display

A display on the top of the unit provides access to all the internal controls as well as showing the results of individual patch readings & built-in tests.

The SpectroDens comes in 3 different versions depending on the functions in the instrument:

Software

Techkon provides their free SpectroConnect software that is available for Windows computers only. It is not available for Mac. SpectroConnect allows the unit's measurement data to be transferred to a computer for a variety of uses, including measuring a media wedge. For those who are used to a wizard-like program that will walk you through the steps of measuring a profiling target, this is not the easiest software to figure out. The instrument has come from the world of press-side measurements and this software is really intended to support extracting small numbers of measurements, and loading digital color books onto the device. It is best thought of as a connection module, firmware updater, a set of measurement tools, all rolled into one.

Also available is Techkon's ExPresso 4 software. This is a printing workflow coordinator, where a printer can keep track of their print jobs, what press they are from, which color bar was used, and basic printing & measuring conditions. This software is only available for the Premium version and costs several thousand dollars.

Of course, no Instrument Spotlight would be complete without us mentioning that we support this instrument in our Maxwell Client and Curve4 software packages. (More on this below.)

Charts

CHROMiX Measurement Module using X-Rite i1IO target reference

For its essential purpose - getting Lab readings from individual patch measurements, you don't need a chart since you're just choosing and measuring a small number of patches, one by one, and reading the results off the back of the device. When it comes to using the SpectroDens for scanning large charts for profiling and the like, software solutions are not common. Techkon does supply their own software that can do this, but it is only available for Windows, and there is quite a learning curve to figure out how to make it all work.

The easiest way is to use the measuring module in Curve4 or the Maxwell Client, and then export the measurement to profile-making software.

The CHROMiX measuring module allows for many different target definition references to be used. You can use targets that are made for your particular profile-creation software (for example: i1Profiler, CoPrA, Barbieri) and in most cases, the SpectroDens will read these charts without any problem.

Wireless operation

A great feature of the SpectroDens is its ability to communicate to a computer over Wifi. Especially when it comes to scanning an entire chart, its rather convenient to be able to be several feet away from the computer and not have any cables in the way. This also enables making spot measurements right on the press.

Cross-Platform issues

As noted above, the Techkon software is only available on the Windows platform. Also, both wired and wireless connections on a Window machine require a "TD Service" program to be installed and connected to, in order to talk to the instrument. It's not the simple USB plug and play that we have become familiar with in recent years.

Techkon has provided some developers a more conventional USB driver connection for the Mac. So wired connection to a Mac is as straightforward as plugging it in, for those apps that run on Mac.

To make things even more complicated, if you want wireless operation on a Mac, you still have to come up with some way to run the TD Service program on a Windows system because that is the only means Techkon supplies to connect wirelessly. (Some Mac users run a Windows platform in an emulation app like Parallels in order to run wirelessly on a Mac.)

Our Curve4 and Maxwell apps are available for Mac or Windows, but have the same restrictions in Windows as described above.

Measurement Modes

All versions of the SpectroDens can measure using all four measurement modes: M0, M1, M2 and M3. Like the eXact, it's quite a treat to have an instrument that can offer you polarized measurements in a handheld scanning package.

Speed

Techkon thinks much of their scanning speed on this instrument, and I have found that it's rarely the speed of the instrument that is a limiting factor. For a page of patches, how fast it gets measured largely depends on how fast you slide the instrument along the row without making human errors. Most handheld scanning instruments like this will have some natural limits to how fast you can scan without sliding off the row, or stopping on the wrong patch, etc. We found the scanning speed to be comparable or better than other hand-held instruments. For perspective, I scanned a single page of 960 patches in about five minutes.

Accuracy

Techkon has a long history of making quality instruments. The published specs reports an astonishingly small .03 difference using dE*a*b for inter-instrument agreement and also for repeatability with the same instrument. Delta E*a*b is a slightly different formation than what we normally see. This means that only the hue and saturation is taken into account in this figure, but not the lightness/darkness. In our own in-house tests, we have seen our unit put out an average dE00 of .31 with a max dE00 of .70. Your results may vary according to how smooth you are at sliding the unit, how big the patches are, etc.

Aperture

The SpectroDens generally comes with a 3 mm aperture, which is suitable for most modern printing applications. One can also choose to purchase a unit with a smaller 1.5 mm aperture at an additional cost. These smaller aperture sizes would not be suitable for coarse printing systems with lower dpi settings, and some loose fabrics. For those, you would want an instrument that measures a larger area so as to get a more accurate representative sample of the color.

Ease of Use

These folks must have some kind of patent on the idea of an aperture tube that is formed into the edge of the instrument. The user can always see the patch that is being measured, whether in spot mode or scanning an entire row of colors. It's hard to describe how simple and intuitive this is. There is no need to fold down a part of the instrument to engage the measurement or use an aiming aperture when you're covering the patches with the instrument. You literally just point and click.

Portability

While the SpectroDens is about the size and shape of a brick, its actually rather comfortable in the hand. It has a nice combination of solid weight to it, as well as being easy to carry, hold and manipulate in the hand. The location of the green measurement button is so ideally positioned that I am frequently waking it up and taking measurements when all I was trying to do was pick it up. If you read my comment on the battery life (below), you'll see that unintended measurements are not a big deal.

Affordability

This is one of the better hand-held devices in the world today, and the price tag reflects that. The SpectroDens 4 Premium version is $7267 at CHROMiX.com.

Unique features


This is a great instrument. If you are fortunate enough to have one, then you will have nothing to complain about - or wish you had that you don't have - for years to come. This has it all. The one thing that prevents more people from owning a SpectroDens is the price. I've never known anyone who owned a SpectroDens and didn't love it. Once a company or a purchasing manager makes the decision to make the purchase, it becomes a dependable workhorse in the company for a long, long time.

Thanks for reading,


Patrick Herold CHROMIX, Inc.

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