BenQ TH680/MH680 and Acer H6510BD

[retoras]

Does anybody know anything about possibility to change the focal distance of these projector's lenses? I am going to build my DLP printer and need better resolution for bigger build platform. These two projectors have 3000 lumens and good contrast 10000:1 what makes them proper for good quality prints.

[PacManFan]

Generally, what you have to do is remove the lens assembly and add a 2-4mm spacer between the lens and the housing. This will change the focal distance of the projector to a much short range. You can also try to find another lens to go in front of the projection lens to shorten the throw distance.

[HTL]

I have a note on this
Close Focusing A DLP Projector:
http://projectsinterestsandetcetera.com ... g-notes-1/

[Finhead]

I just got my Acer H6510BD last night. There are no mods you'll need to do to it, focus is fine at 1920X1080 at approx 225mm distance. Make sure you wear eye protection when your testing it at that size, it is super bright.

Clinton

[watsonstudios]

What size build area does that focal distance give you?

[retoras]

Thanks for your answers. I thought earlier about the spacer, but close-up lens lets me keep my guarantee I will share my results with you.

[Finhead]

[watsonstudios]

[Finhead]

Nope that went over my head. Lol
For some reason I thought to get 1:1 or 100 micron in the XY you needed to use the projectors native resolution. I wouldn't mind a slightly larger build area but not sure how to set that up.

[watsonstudios]

Haha, sorry about that. Start with your build size. How big do you want the build envelope to be? Once you determine that, then we can figure out how to set up your slice images to be 1:1 size.

Native projector resolution has nothing to do with build size. Of course a 1920 x 1080 native resolution projector will give you almost double the resolution at a given build size than a 1024x768 native projector.

So lets say you want a 10" build size for the long end. the aspect ratios are different between a 1920x1080 and a 1024x768 projector so the XY envelope will be more rectangular for the HD Projector.

With your HD projector, and the build size at 10" x 5.62" the print resolution will be 192 pixels per inch at 1:1.

With my 1024x768 projector, and the build size at 10" x 7.5" the print resolution would be 102 pixels per inch at 1:1.

So at the same relative build size, your HD projector is almost double the resolution than your typical 1024x768 projector. Hopefully someone who knows CW better will chime in and help with the size setup.

Jon