Hi,

Im about ready to buy my lenses, but when using focalcalc, i get the impression that neither of the fresnels has a large impact on final image size, and this rests mostly on the doublet. Is this true?

Also, provided the above statements are correct, then how does one go about choosing each lens, and what makes say a 650 better than a 450? (apart from the fact that the collimator or however its spelt should be a shorter focal length).

Finally, one last question i would like to bundle in, is is a 19" widescreen a bad idea? I got it for 70 bucks used so i couldnt pass it up (i work at best buy, it was missing a stand and cables; SCORE!!! , normally $190). Anyhow, as i understand i will probably loose some light, but is the 19in lens on lumenlab designed 4 widescreen? What other side effects are there if any?

Thanks a bunch for any thoughts and ideas this community is always full of,
Travis

ok, i just found the answer to my last question; the lens is widescreen. I didnt think it said on the store for some reason. Anyhow help on the above questions would still be great!!

travis

one more question, how does one change the view format on a page from 'view topics' to 'view posts'. I found in in the advanced search, but cant on here...

Below is a little information that I like to pass along to new members:

The best place to start is The Lumenlab PRO DIY Projector Guide V.3.

Once you have a grasp of the basics, you might want to peruse the pinned topics at the top of the Beginner's Forum. This is also where you should go to create your own threads when you have questions. When you start your build, you can create your own PLOG to chart your progress and to ask questions about your particular build.

Then you can move on to the pinned topics of the DIY Video Projector Design forum and the FAQ section.

When you're ready, you'll need to decide what parts (LCD, Fresnels and triplet) you'll need. To do that, you can use the handy FocalCalc. FocalCalc will help you determine your enclosure measurements and will let you experiment with different parts before buying anything. This will also tell you how far from the screen your projector needs to be (throw distance).

I've found that Google Sketchup is handy to use to design and visualize what your projector will look like. And best of all, there's a free version you can use.

A lot of the questions you might have probably have already been asked and answered several times. While most of us do not mind answering some of the same questions repeatedly, you might get more satisfaction in finding the answers yourself. Unfortunately, the built-in Search feature on most of these online forums is quite limited in what it can do. You might find it easier to search using Google using the "site" parameter. Below is an example:

Google search: site:lumenlab.com +"12.1" projector +plans

You can find other parameters by clicking the Google links in my signature.

You might run across a "quirk" when searching using Google, however. If you notice the thread looking "wonky" like this image, simply go up the the top right corner of the thread and click on Options and then Switch to: Standard.

I hope this gets you started on the road to your new obsession and I look forward to seeing your progress.

The triplet AND the collector fresnel together determine the throw and projection size. The focal length of the two should match pretty closely.

Whether you want the Standard (330mm) / Pro (650mm) / or the 450mm is determined by what size you want the projection to be.

The Pro Lens and the 450mm will work with a 19" widescreen. The problem with 19" Lcd's is the box size is HUGE and it really has no advantage over a 17" Lcd.