I've made a start... I got my OHP! :)... help required.

[mick-uk]

I finally made progress I'v got a ohp with the following specifications on its way to me:

Metal halide bulbs
575W
External fringe control
317mm (3 element) focal lens
7000 Lumens

I have my screen 80" wide...

Now all I need is a panel! 🙁

Anyway... I do have a question, Metal halide bulbs... I've never heard of them myself, they sound expencive! how much should I expect to pay for a replacment 575W MH bulb? (average price)

Also... what is external fringe control?

Oh... any suggestions for a panel, that could complement my ohp nicely and give a good image?

Thanks.
Mick

 

[jcbklyny]

OHP bulbs arent usually very expensive... but they dont last very long. Search the fourm for some ideas on how to fit a new lamp into it and you can take it from there.

 

[Dolphin]

Mick,

I too am new at this do it yourself projector thing. From what I have researched... the best LCD Projection Panel is the Sharp QA-2500. The average price is around $300 on Ebay. There happens to be one on there right now. The url is the following:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3050305389&category=1499&rd=1

Your OHP is very nice. 7000 Lumen!!! Very bright!!! From what I have seen on the internet the 575W MH lamps cost around $100. I'm not sure how long the lamp life is though.

I'm not sure what an external fringe control is at this moment. But I will try to find an answer for you.

I have also learn that you can dismantle a LCD sreen for your overhead projector and they have some amazing results. But that is above my skill level at this moment. Look around the threads for more information.

I do have one question for you. You said that your OHP produced an 80" screen. What is your distance from the projector to the wall to produce a screen that size?

The reason why I ask is because I recently purchased a Sharp QA-2500 LCD Panel and a Dukane 4003 OHP (only 4000 Lumen). But... since I'm currently in Iraq... I haven't been able to set it up. I'm just trying to get some distance to screen size information before I come home and set up my projector. Any assistance would be greatly appreciated.

Thanks,

Dolphin

 

[henrik_mork]

I finally made progress I'v got a ohp with the following specifications on its way to me:

Metal halide bulbs
575W
External fringe control
317mm (3 element) focal lens
7000 Lumens

I have my screen 80" wide...

Now all I need is a panel! 🙁

Anyway... I do have a question, Metal halide bulbs... I've never heard of them myself, they sound expencive! how much should I expect to pay for a replacment 575W MH bulb? (average price)

Also... what is external fringe control?

Oh... any suggestions for a panel, that could complement my ohp nicely and give a good image?

Thanks.
Mick

Mick, nice to have such a powerful OHP to start with!

Fringe control is the control that raises and lowers the mounting that holds the bulb - it is to eliminate coloured halos that can sometime appear arround the edge "fringe" of images.

I too have a Metal Halide OHP in the garage - I mainly use a halogen OHP (4000 lumens). (Bulbs are £7.99 - 75 hour lifespan)
My Metal Halide uses 575W HMI SE (single ended) bulbs. These have an average lifespan of 750 hours and are the most common Metal Halide OHP bulbs in European and UK OHP's.
The cheapest price in the UK is from www.aalighting.co.uk - last time I looked they were about £86.00 + VAT. Postage is around £6 via Securicor next day.
Beware, especially in the UK bulb prices can vary wildly depending which company/shop you use - I have seen some firms charging up to £200 for these HMI bulbs.

 

[mick-uk]

Thanks for the info guys... I appreciate it.

Dolphin... I say i have a 80" screen, but what i meant was I have the screen on the wall 🙂... I havn't actually switched the projector on yet.
Sorry I cant help.


Mick.

 

[henrik_mork]

Mick,

.....................

I do have one question for you. You said that your OHP produced an 80" screen. What is your distance from the projector to the wall to produce a screen that size?



Thanks,

Dolphin

Dolphin, I would guess that the projection distance in this case for an 80" image is about 2.75 - 3.00 metres (9 to 10ft) from the front edge of the OHP to the screen surface. This is based on my set up with a 10.4" TFT panel and a standard overhead triplet lens.
Hope that's some help.

 

[borinqueno]

Focal Length and Projection Distance

Hello,

This is my first post to the board. I found it by luch when searching for 3D projection. This forum is great! I got the video projection bug fever. I'm new to this. I'm thinking on going the easy route...OHP and LCD panel. For what I hear there might not be many LCDs available for sale in eBay by the time I start searching. I saw good designs in this forum. Amazing! Keep the good work.

Now, it would be nice if as part of your results you identify the focal length of your OHP and the projection distance to achieve certaing diagonal length for the picture.

bless you all and keep on projecting!!!