My experience: excellent on the cleaning, both of the glass just in front of the bulb, as well as the more advanced internal cleaning as posted a few pages back by avzector and described athttp://www.avforums.com/forums/proje...-part-1-a.html
In advance, thanks all for discovering and posting clear instructions - without a doubt the best regular maintenance tweak to the visuals I have come across since calibration of grey scale.
Summary of results:
- I am on my second bulb and about 800 hours into it
- I replaced my first bulb after only about 800 hrs and was dissapointed with the improvement - likely my first bulb is fine, and the dirty glass/prism was the real issue I was trying to fix - fortunately I saved my first bulb as back up as there is probably some life left in it still
- I did not do a before and after measurement of ANSI or On/Off contrast ratio, but visually I would say on/off is not impacted, but ANSI definately is much improved visually (looking at white movie credits on black background)
- estimate of increase in brightness definately in 50% range - change in overall snap to the picture was very obvious for me
- initially I cleaned only just the glass in front of the bulb - there was a mild colour shift, and a large improvement in brightness and perceived ANSI
- this weekend, I took apart the projector and cleaned thoroughly the inside face of the glass as per link above, and the exposed sides on the other prisms/diffusors as best I could
- I did not notice any residue on the cleaning materials on either the external nor the internal cleaning, but cleaned anyway just using some standard camera lens cleaning fluid and wipes
- the glass the everyone is cleaning itself must have a anti-relective coating as it looked a tiny bit yellow under daylight flourescent lights- perhaps the cleaning allows for the anti glare/relection to work better?
- there was a very substantial and easily visible colour shift following the internal cleaning which surprised me as I was not expecting much difference
- Measurement of the post internal and external cleaning with Colorfacts showed the Red had dropped relative to Blue and Green by 20%, and dE was approx 40, instead of more typically following a good calibration dE of 0 to 2 or so (and where it was prior to cleaning)
- in essence the accumulated dirt/grime on the glass must be absorbing blue and green light, but less so for red, as well as scattering the light somewhat
- a quick fine tuning of the grey scale and gamma last night brought everything back in order and the picture improvement was fantastic - back to brand new again!
Thanks all, and I will try to do before and after on the next go around after around 500 more hours.