The Art of Home Theater Projectors

InFocus SP8602 Projector – Dynamic Iris upgrade with new firmware


Sorry, wanted to get this up before the holiday weekend, oh well.

The really short version is the iris action is much improved. It’s still not the least visible around, but in some troublesome scenes the improvement is dramatic.  One of the areas where irises can get to be noticeable and annoying, is in darker slow moving scenes, usually two people conversing, with the camera shots enough different in brightness that you see the effects of the iris opening every time the cut to the brighter of the two, then closing when it cuts back.  You get the same effect on movie credits when they fade in and out.  No one cares on the credits though.  I also checked out some other types of scenes such as the underwater scenes in Hunt For Red October – there aren’t many of the subs but a couple can drive some irises crazy.  That was one of the examples I showed BenQ when pushing them to improve their dynamic iris action.  Well, life is good -both projectors improved significantly from “nasty” to just minor visibility.

I get spoiled watching my JVC with its lack of a dynamic iris. This may make me a bit less tolerant of the more visible iris action, than others, but, when I do yell ‘problem’ at a manufacturer, it really does need to be improved.  Of course, there will be continued improvements made with new algorithms over time, just as we expect with creative frame interpolation as well.

The nature of what is being accomplished with dynamic irises demands that the iris action is detectable.  The trick is to minimize its visibility.  The more range – the more you want to be able to close that iris down, when needed, also means you are expanding the maximum amount of change, and that just makes it more visible.  There’s no perfect answer – therre will always be some scenes/scene changes, that will cause dynamic irises to occasionally become noticeable.

I still don’t think the InFocus has the best overall iris action. While it could still be improved, InFocus accomplished what they needed to, taking the SP8602 iris action from occasionally annoying (which is unacceptable), to being fairly typical, and therefore acceptable to almost everyone.  We all know we are accepting the consequences in exchange for blacker blacks, especially on those darker scenes.

I am relieved.  Without a respectable fix, I would have regretted giving them the benefit of the doubt – and a Best In Class – Runner-up award.

I dropped off the InFocus SP8602 at UPS this afternoon.  Ahh, I really did like it’s nice bright image.  Fortunately I am now watching / listening to Paladia on HDTV – found a Glastonbury 2005 music festival performance, and I’m doing it on the Runco LX7, a 3 chip DLP which is even brighter… wow. -art

News And Comments

  • PatB

    It seems to me that the dynamic iris is a very temporary technology that may not be available on any new model projector quite soon.

    Last week at the hardware store I was stunned to see that all new flashlights used LEDs. New car tailights are LEDs too.

    You only need an iris if you can’t cycle your light source. So when LEDs dominate projectors (soon I think) no more dynamic irises.

    The second generation of projectors (after the Advent Videobeam) were only about as bright as many low cost LED projectors right now. The Sony GS70 was about 200 pounds and 200 ANSI lumens. It couldn’t quite do 1080 HD but it had great blacks.

    I’d buy a thousand dollar 300 lumen LED projector in a heartbeat.

    • Lisa Feierman

      Hi PatB,
      Yes, your logic seems good. Further although LED light sources are not one led per pixel, but rather larger areas, those areas could actually be organized into a number of zones, and with sufficiently clever algorithms, you could lower the black levels in areas without a any bright, but would have to work your way back up in brightness as you get closer to a bright part of the image, The change would have to be blend in and not be noticeable. As to 300 lumen LED projector – sorry not bright enough for me, and certainly not even remotely close if 3D is going to figure in.
      As to the $1000, sure, you can already buy what you want – Casio has 4 dlp projectors with what are actually hybrid – led and laser, light sources, that sell for under $1000. They are all DLP, though small biz projectors… and they claim 2000 or 2500 lumens -a

  • Gary J. Svehla


    I just upgraded to firmware A72 and
    I was bothered by a whole new problem.

    I was watching a black and white classic
    film, and while the iris pumping before
    was noticeable and slightly bothering,
    the new problem is even worse.

    During this black and white film, I saw
    more flaring up of white glare on people’s
    faces and foreheads (the solution being to
    lower the brightness slightly, which
    darkens the picture more than needed) and sometimes
    the entire cut-to scene would noticeably darker
    and grayed out. These types of things were far
    more distracting than the image I got using
    firmware A65 (which my replacement projector
    shipped with).

    I switched the iris from Auto to 80% and
    then back to auto and the problem seemed
    to be a little less (after the upgrade I thought
    the iris might need to be “worked” a tad).

    I plan to watch some modern color blu-ray
    stuff today, but so far, I notice the iris
    action more and not less. Hopefully, after
    this one day break in period, perhaps the
    problem will lessen.


    • Lisa Feierman

      Interesting. I missed noticing anything like that while I had the newer firmware, but that only means I didn’t notice, not that there is no issue.
      Sounds like crushing near whites. That makes sense, as InFocus basically has now told the iris to partially ignore small very bright areas on generally dark scenes. Of course the easiest way to flatten out those foreheads is to avoid dynamic features, be it irises or various dynamic contrast, Brilliant Color, etc. Hopefully you’ll come up with a combination that works well for you. Let us know. -art

  • Gary J. Svehla


    After using the projector for
    several days, the problems stated
    above appear to be gone. As I
    suggested, it seemed with the new
    firmware upgrade the iris needed
    a little break in time. I may
    still be getting a little more
    “glare” (slightly more) on people’s faces and
    foreheads, but the other problems
    hopefully are gone for good.

    The projector, for the money,
    appears to be the best choice
    in the 5K arena. What was very
    good is now excellent.