hello everybody, i have searched the forum and couldn't findthe answer to this,
i was using Gunawan's program to calculate the projector.
here is what i did:
1. i have a common OHP fresnel 220/330, so i put "330" as the focal of the top fresnel.
2. i have a 15'' LCD.
3. i am going to buy an objective with appropriate characteristics.
since i need a 360 cm diagonal image on a screen while the projector will be at 300 cm to screen.
since the focal length of the top fresnel must be a bit (1,1~ times) longer then the distance from the LCD to the objective, i assume it should be 31-32 cm.
this being the case, i can only use an objective with the focal range less then 32 cm!! this means that if the diagonal of the LCD is 38 cm, the image projected would not be so even, as it would be if i used an objective with larger focal length (e.g. 35-36 cm).
is there a way out of this?
i was using Gunawan's program to calculate the projector.
here is what i did:
1. i have a common OHP fresnel 220/330, so i put "330" as the focal of the top fresnel.
2. i have a 15'' LCD.
3. i am going to buy an objective with appropriate characteristics.
since i need a 360 cm diagonal image on a screen while the projector will be at 300 cm to screen.
since the focal length of the top fresnel must be a bit (1,1~ times) longer then the distance from the LCD to the objective, i assume it should be 31-32 cm.
this being the case, i can only use an objective with the focal range less then 32 cm!! this means that if the diagonal of the LCD is 38 cm, the image projected would not be so even, as it would be if i used an objective with larger focal length (e.g. 35-36 cm).
is there a way out of this?