CurtPalme.com Home Theater Forum

[benareeno]

Just curious...as there are a lot of brainiacs on here.

Could I increase the distance to the lense? Or do any other type of magic to increase the throw of a lense?

[Tim in Phoenix]

Doubtful

You are already varying the lens to tube face distance when you focus. No one really ever made "zoom" lenses for CRT, too much light lost or just too costly.

[the big E]

I'd say cost was a factor as to why there is no zoom lens on crts as they were pricey as it was

If you do want a different throw rate get different lens

[CasetheCorvetteman]

Cost has nothing to do with it id say, my question is why youd want zoom lens on a CRT, and how you would go about getting everything perfect on each lens after you f***ed with it, id expect it to be very impractical.

Its quite practical on a single lens device, but 3 lens systems youre adding an extra adjustment in there to make it all the more complex for perfection.

Just curious as you say, but are you asking because you got yourself a rear projection screen and found out it looks sh** house because your throw distance is too short and you can see colour impurity?

[benareeno]

I just hate having the projector right over my head...which is usually where it is when setup properly.

I have it behind my right now...mounted just above the couch and with zero keystone, but not a full raster by any means.

Pic is still great, but I'd like to use more raster....but, then again...at this stage in the game, who really cares. I may as well just use it in a practical way and wait for it to die:)

[tschaeikaei]

In the DIY- projector community were some guys who did a (german) Brillenglas- mod.
Brillenglas means the glas of glasses. The glasses you use to correct your eyes.
I hope you understand
They added a further lens to increase or decrease focal length.
One problem: I dont think you will get a normal glasses lens with a diameter that fits with a CRTs lens.
Best regards, Julian

[CasetheCorvetteman]

At this stage, who cares where it is in relation to your seat? You looking at the screen or ceiling?

Just set it up CORRECTLY and stop trying re invent the bloody wheel!!

[benareeno]

would the lens be under the current lens or on the outside of it? what if i could shrink the image on the tubeface with some thin lens that fits under the current lens?

[CasetheCorvetteman]

No.

[CasetheCorvetteman]

No.

[CasetheCorvetteman]

No.

[the big E]

If your dead set on a different throw distence get different lens

Besides you never posted what lens you have currently

I swapped out the HD-10's my marquee had for the gt17's huge difference in throw and image size

[CasetheCorvetteman]

Youre 2 months late mate

[the big E]

I know
I forgot to look at the date again

[AnalogRocks]

To increase throw start lifting weights. You'll be able to throw the lenses MUCH further.

[AnalogRocks]

To increase throw start lifting weights. You'll be able to throw the lenses MUCH further.