Picture quality ultimately is what matters most when purchasing a projector and how sharp the projected image is clearly is one of the characteristics each manufacturer should strive for. The Casio XJ-ST155 did a very nice job in its native resolution of 1024x768 when it came to displaying small type faces. This was expected, however what was nice to see is that the XJ-ST155 also did a very acceptable job of displaying even higher resolutions. The max resolution of the XJ-ST155 is 1600x1200 and although I would want not want to use a projector with a native resolution of 1024x768 in 1600x1200 resolution all the time, for certain times when you need it, this projector could do the job. When displaying resolutions inbetween the two mentioned above the projected image was still sharp but you do see it start to degrade a bit. Which, is also expected since it is a compressed image. Photographs can only partially capture what you would see if you were there in person, but the pictures below give you some indication of the projectors ability to handle various resolutions. Click the image to see the non-cropped view of the projected text.
Color reproduction is always an interesting part of any projector evaluation since not all projectors display color the same way. Plus, not all are exactly accurate. DLP projectors have struggled with color reproduction since their inception. I was hoping that Casio might have produced a DLP projector that didn't suffer from the issues that plague most DLP projectors but the XJ-ST155 does have the usual hard time with reproducing yellows and reds. Yellows tend to be a little greenish where as reds a little orange. I will say there was improvement with this model. The pictures below attempt to illustrate this point but I must say photographs are no match for seeing it in person.
I should also mention that this color accuracy issue should only give you caution if you are presenting content that absolutely, positively has to be on the extreme level of color accurate. And I should also note that when showing video content, which this projector does a great job of, the issue is non-existent. So, although the XJ-ST155 has all the same color issues as other DLP projectors, it still produced a much improved image compared to other DLP projectors in its class.
One wouldn't expect the video performance of a business class projector to produce an excellent image, but the Casio XJ-ST155 exceeded my expectations. With a lower than average contrast ratio of 1800:1 for a DLP projector, one should not expect black levels of that of a much more expensive home theater projector. However, in terms of video sharpness and brightness, the XJ-ST155 produced a very nice image with an HDMI signal from a PS3 It produced a fairly decent image when using component as well. Video played from a laptop was compareable to video using a component source. Both were satisfactory. In a classroom environment the quality of the image is enough to keep students engaged and free of any eye fatigue from poor image quality.