CurtPalme.com Home Theater Forum

[Corleone88]

Hello,

I have a bg1209s with HD300 lenses. According to the Barco lens calculator I could get a 300cm width picture from a distance of 421 cm between the screen and the front of the support. Unfortunately I have picture looking more like a 280cm width. So I was wondering if I made a mistake somewhere and if this is the case, if by changing the lens(with smaller throw distance maybe hd120 or hd180), I can get 300 width?
I could not find the specs of these hd300 lens?
Thanks for your help

[gjaky]

The HD300 lens is the same as HD-10 GT26. For that the lens throw is 1,54 x width+1,24cm, so what you get is about right. The shortest throw lens is the plain HD10, which has a throw ratio of 1,25 x width + 15,24cm, so from 421cm trow you should expect a screen width of 320cm, so in fact you'd have to move closer the projector for 3m screen width.
On the other hand HD10E/HFQ900 lenses offer superior performance over the plain HD10 and have a throw ratio of 1,269x width + 33cm, for 421cm distance it would throw a 305cm wide picture.

[Corleone88]

Thanks gjaky. The distance of 421cm is not from the lens but from the front of the ceiling mount (see the barco lens calculator). From the front of the lens I have 403cm. I did not feed the pj with a source, so I measure the width of the picture from the green grid used in the setup.

[gjaky]

Internal patterns are always wider than actual sources...