TV Calibration vs. Auto-Calibration: What's the Difference?

The discussion here was inspired by a letter from a reader. He noted that in a recent review I mentioned that the set in question offered auto calibration. But the remainder of the letter suggested that my comment was misunderstood (or perhaps not precise enough to begin with). In the review/calibration/video-crazy business world, auto-cal refers to a specialized subroutine in a standard calibration program such as Calman from Portrait Displays. A different version of this subroutine exists for each brand/model of TV, and perhaps even for each year of each brand/model. Once set up it's fast and accurate. But this auto-cal requires the same expensive test gear and calibrator training as any manual calibration.

Auto-cal makes sense for a calibrator who does dozens of calibrations a year. But for a reviewer who does less than 10, keeping up with the various iterations of auto-cal for each set, and each year of each set, makes no sense. The result of a manual calibration is unlikely to be visibly different from the auto-cal version. But an auto-cal option offers a higher degree of precision and speed, both of which are critical in some corners of the professional video market, such as on the displays used in transferring a movie to home video, or those used at a streaming service such as Netflix to ensure that what they're sending out is performing properly.

But the type of auto-cal the letter-writer thought I was referring to (but I wasn't) is a feature that's been tried by some set makers. It makes use of the camera in a smartphone (usually a specific version, such as a Samsung phone for a Samsung TV) that reads a test image from the TV screen, analyzes it for accuracy, and makes the appropriate corrections to the set's color controls. But according to the ISF (imaging Science Foundation--the organization that trains and assists most pro calibrators in the USA) this feature hasn't been good enough as yet to gain much traction. The smartphones available lack sufficient precision, particularly at low brightness levels.

If you've been following Sound & Vision for any length of time, you're likely aware of what a home display calibration involves. But not all readers are. Typically, a well-trained technician shows up at your house with a suitcase full of test equipment and a computer loaded with calibration software. He or she (though I suspect the latter are rare), spends a few hours tweaking your TV for all it's worth.

And it's worth more than a few dollars. Professional home calibration isn't cheap, as even getting into the calibration game involves a significant investment in time and money, often involving thousands of dollars in hardware and training). So a calibration will likely run you a minimum of $300 (and up), depending on the complexity of the setup and the number of different setups involved. Often, but not always, separate calibrations are desirable for SDR and HDR—and possibly even different setups as well for the two most common versions of HDR: HDR10 and Dolby Vision. Separate setups for day and night viewing are also be a good idea. But if you do your most critical viewing at night in subdued room lighting, you can probably make do by calibrating for a darkened room and turning up the backlight control (for LCD sets) or OLED light (for OLEDs) for non-critical daytime use. Just remember to turn it back down at night!

The result of a careful calibration can range from subtle to substantial. The TVs of most casual users might well still be in the same picture settings as they had when the set was delivered. In that case the post-calibration changes should be obvious and substantial. But not all viewers will like the result at first. They've become accustomed to an uncalibrated image that's too bright and too blue. But if they give the new, calibrated look a week or two they'll rarely go back.

The first step in any calibration is to select the best picture mode, which is something you can do yourself. These have names like Movie, Cinema, ISF, THX, and Filmmaker, the latter a recent entry available on some models. Modes you should steer clear of might be called Bright, Vivid, or Dynamic. Standard is also a common, out-of-the-box option, often producing the overly bright and blue look referred to above. There's rarely anything precise or "Standard" about it.

That done, a calibration next involves setting the overall video output,— getting the peak white and black levels correct. That's the part of the process requiring the least investment in equipment and training. If you have a Blu-Ray player, test discs that can help with this are available and affordable. They include the Spears & Munsil High Definition Benchmark and the Spears & Munsil UHD HDR Benchmark. Ample information on how to use these is readily available on-line. Indeed, for many buyers this might be sufficient if it follows good choices of picture mode and color temperature. The latter is almost always best in Warm (or one of the Warm settings—some sets offer two of them).

Then we get to the fun stuff: color calibration. This requires the most extensive and expensive test tools to do precisely. If you don't have these you can try the settings that appear in some reviews (including ours). That won't hurt anything (you can always go back, though I recommend you write down all of the original settings before you change them!). But such generic settings can be a crap shoot given the sample variations inevitable in even the same TV brand and model. It might be just as likely that these settings won't produce better results than the set's default color settings. The as-delivered color settings on many new sets, particularly premier models, have been getting closer to optimum. Not perfect, but I can't recall any recently reviewed set that looked unacceptable in those out-of-the-box color settings, given a careful choice of picture mode and color temperature.

Nevertheless, a professional calibration can provide a reasonable assurance that your TV will look as accurate as it possibly can. Whether or not this will be money well spent will depend on how fussy you are (and if you're reading this it's likely you are) and how much you paid for the TV (or projector). $300-$500 spent to get the best from a $3000-$5000 set might make more sense than it does on a $1000 TV. But in either event some time spent on the DIY recommendations above can pay off. Before you spend serious money on a calibration, however, it's always a good idea to first put 100-200 hours on the set to let it settle in. I usually end up closer to 50 hours for a review, since a longer break-in period is impractical since readers want reviews yesterday (at 4 hours a day that's nearly a month for 100 hours or over 7 weeks for 200, before even breaking out the test equipment!).