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Projector Calibration


Ray Groome

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At my Photographic Society I am responsible for the operation of our Canon SX60 projector. (We use it in the digital mode using a HDMI cable) I have profiled it using a Spyder 3 instrument and was disappointed to find I had to make further significant adjustments to the projector (Brightness, Contrast and colours) based on visual observations to obtain reasonable results.

I have also tried profiling it using a Colormunki Photo but that gave very bad results, which I abandoned.

This is not a PTE problem as we are using other software for this application.

I am seeking good accuracy as we use this projector for competition work.

Any recommendations, please?

Ray Groome

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My recommendations is to clear all the calibrations and use the projector as it is. I have been and done much the same as you describe, but the results are no closer than spending 30 minutes doing it manually. The problem is that if you start to change individual colours the projector may look really good until you get a picture with one prominent colour then I found that colour unacceptable. Fix that one and another drifts off.

I am fairly patient, but in the end I gave up and all I would do now is maybe contrast and brightness and a little saturation, but that is probably best done in the club room one night when you can set up 30 minutes early and get all the lights out. Then you can put through a varied number of images from members and try to zero in the best you can. No matter how much effort you make you will always find one person who wants it darker or lighter to match his images :-)

I am fairly fussy, but the vast majority of club projectors I use are OK. We just have to expect a little variation between the PC screen and the big screen. Perhaps the thing to do is to turn off the laptop screen so members are not continually comparing the two, or set it up where they can't see it. As you know, you get a different picture depending on the angle of the laptop screen. Our projector is a top of the range Epsom at 1920*1080 and its very forgiving. Meaning that it smooth's out pixels from over cropped images and deals with light skies great too, so all in all it helps far more than it hinders.

Yet only this week one member wanted me to alter it because he didn't feel his images were seen the same as on his screen at home. Best of luck with the calibration and if members give you a hard time, call them in one night and hand it over to them to sort out. They won't be able to sort it out, but it shuts them up .....usually :-)

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Thanks for your comments

Luc,

That looks a good test image. Yes, I have set the projector in sRGB mode.

Barry,

I was hoping to find an instrument that would provide a simple solution, but it does not sound as though I will be lucky! If I delete the projector profile I will be left using the laptop profile, which will certainly give poor results on the projector. Unfortunately, adjusting brightness, (or gamma) and contrast does not solve all the problems. However, the Canon projector does allow me to adjust the hue and saturation of individual colours and with a lot of patience and luck I have managed to make significant improvements over the profiled settings. I note your warnings about the colour correction may not work for all images.

I hope X-Rite and DataColor read our Forum! They will be disappointed at our conclusions.

Ray Groome

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Hello Ray,

I am in the same position as you, as I was the one in our club who chose and purchased our projector, a Dell 4320 DLP machine, reputedly better than LCD, but that's a matter of opinion I think. I calibrated it with a Spyder pro II colorimeter with, I think good results. Those who comment on image quality are invariably comparing it with their own monitor, which is usually uncalibrated anyway, so their opinion doesn't count for much with me. Judges are some of the worst, they say things like the image looks different to their view on their monitor at home, clearly implying that projector is wrong and their (usually uncalibrated) monitor is right.

For what it's worth, here is how I did the projector and laptop - a Windows machine. First, make sure that Adobe Gamma is not active on the computer. If Photoshop is installed, you will have to get into the startup program list and disable Gamma, or else it will upset any calibration attempt. Set the projector to factory specs and sRGB.

While one is supposed to let the Spyder look at the screen to do the calibrating, I actually mount the Spyder on a tripod about 2 metres in front of and looking at the projector. I have an ExpoDisc white balance filter for setting custom white balance on my Canon camera, and I sit this in front of the Spyder as a diffuser for the light from the projector, and to calibrate the projector for a white screen. Then I run the calibrating program. The usual method of aiming the Spyder at the screen is to take into the calculations the colour of the screen, but I find substituting the ExpoDisc works well. I also do not use the ambient light setting, and I set the calibration at a gamma of 2.2 and native colour temperature. The results seem to please most people, and I know the images are much closer to correct than any empirical adjustment by eye can be.

The projector profile, of course, is in the laptop graphics card, so the projector is only correct when used with that laptop. I get trouble with members who insist on using their own laptop and can't understand that the projector is uncalibrated when used with another lappy, especially the Apple aficionados.

However, I believe some macbooks can have dual profiles going, for computer screen and projector at the same time. If they wish to calibrate the projector with their macbook they're welcome to do it themselves.

Colin

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Colin

I can relate to most of your comments.

My Photographic Society rents out several monitor calibration devices to members so that has helped to reduce some of the problems. Fortunately Adobe no longer includes Adobe Gamma in the Photoshop program (I think they dropped it about 8 years ago), but that used to trip us up sometimes.

I found the only way I could check on the accuracy of the projector was to have a separate calibrated desktop monitor in the room with the projector (which was connected to a laptop that was running the projector profile). I then displayed on each device a selection of test images and adjusted the projector controls until I obtained the best correlation. I think a desktop monitor gives a more accurate standard than a separate laptop. But this is all very cumbersome and it would be very nice to have an accurate instrument to avoid such manual adjustments.

Fortunately I have now managed to placate a (very good) critical member of the Society.

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Me again,

I should have pointed out that Windows laptop screens are usually 6-bit, while stand-alone monitors are (mostly) 8-bit, and anyone claiming their laptop is is right, or the standard they go by, is talking nonsense. While calibrating a laptop can improve the image quality, they cannot compete with a good 8-bit monitor. Some very high-end monitors are actually 10-bit, but they cost into the thousands, like Eizo screens. Since most people shoot jpegs, and jpegs by design are 8-bit images, 8-bit monitors are a good fit. Note the graphics cards in lappys are generally 8-bit, it's just the screens are 6-bit, so a lappy can drive an 8-bit external monitor or projector with no problems.

Colin

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