AVS Discussions
  Go Down

DIY contrast enhancements.

alangouger

  • *****
  • 123
  • My avatar, me in my bat cave theater.
DIY contrast enhancements.
« on: June 28, 2018, 10:40:38 PM »
Lets talk DIY contrast enhancements.

I will kick it off.

I have modified several lens over the years adding a static iris. You can easily double the contrast by doing so. Depending how aggressive the iris you can lose 40 to 50% of your light output. A long throw lens will yield better results than a short throw lens. Using the same size iris the long throw will deliver more contrast for less light loss where the short throw will trade more light for less contrast.

Here is a easy mod anyone can perform without having to disassemble the lens. If you are able to remove your lens or have access to the back side of the lens internally than you can benefit from this method. Here is a hint:

http://i31.photobucket.com/albums/c387/itsmeto/aperture_zpsdhkugkwd.jpg
DIY contrast enhancements.



« Last Edit: June 29, 2018, 05:22:22 AM by alangouger »

AVSMike

  • *****
  • 1021
Re: DIY contrast enhancements.
« Reply #1 on: June 29, 2018, 08:42:25 AM »
Having a manual iris is one of the reasons I really like the JVC projectors. I am really surprised more projector manufactures don't include a manual iris.
Mike Garrett
AV Science Sales
585-671-2968
mike@avscience.com

JVC, Sony, Epson, Marantz, Denon, Yamaha, Onkyo, Stewart, Seymour, Screen Innovations, Screen Excellence, DNP, Carada, Da-Lite, Vutec, Triad, SVS, Martin Logan, Def Tech, RBH, M&K and many other brands.

Re: DIY contrast enhancements.
« Reply #2 on: July 27, 2018, 12:22:46 PM »
Another method is to use a color correction filter, like an FL-Day to boost the red which is often the colour that is lacking from the light source (usually the lamp, but some lasers too), which would otherwise require reducing a lot of green and blue to get to D65. By adding the filter you reduce the black and white levels, but can gain some white level back by not having to reduce the green and blue so much, so gain some sequential CR while improving the black level.

Guy Kuo was one of the first people I remember mentioning that over on avs and he used it on his NEC HT1000 IIRC.

AVSCraig

  • *****
  • 2002
  • Home Theater Lover / Sales / Advice
    • AV Science, Inc
Re: DIY contrast enhancements.
« Reply #3 on: July 27, 2018, 12:27:21 PM »
Another method is to use a color correction filter, like an FL-Day to boost the red which is often the colour that is lacking from the light source (usually the lamp, but some lasers too), which would otherwise require reducing a lot of green and blue to get to D65. By adding the filter you reduce the black and white levels, but can gain some white level back by not having to reduce the green and blue so much, so gain some sequential CR while improving the black level.

Guy Kuo was one of the first people I remember mentioning that over on avs and he used it on his NEC HT1000 IIRC.

Interesting. I loved my NEC HT1000 at the time, but was too new to home theater projection to be doing mods like that. And my room sucked back then anyway !
Direct (585) 671-2972 8:30am - 4:30pm Pacific 
www.avscience.com  craig@avscience.com
We carry projectors, screens, speakers, receivers etc. !!
Twitter - @AVS_Craig

Re: DIY contrast enhancements.
« Reply #4 on: July 30, 2018, 12:34:43 PM »
I had an NEC HT1000 too back then, and it was around that time that I'd seen Colorfacts and was lucky to get a package for a good price from Mark Hunter, so after that, I always used an FL-Day on all my projectors and calibrated them to D65. I'd already tried Steve Smallcomb's (sp?) SMART which used a light meter and colour gels but Colorfacts was so much faster and more sophisticated. I just use the light meter for contrast readings now as using a colorimiter (especially aimed at the screen) just doesn't give accurate results. At least the more affordable ones don't. Not that I even do that much these days - I don't feel the need.

Re: DIY contrast enhancements.
« Reply #5 on: November 17, 2018, 12:04:14 PM »
I bought a fl-day filter back 3 years ago. I never really got it to work but i didn't put much effort into it since I had to conceive a way to mount it. Now adays i've got a 3d printer... this thread has renewed my interest in attempting to use it again. Just finished printing out an adapter for it haha.

Any tips on tweaking the green blues? % increase? brightness/contrast/colors?

  Go Up