Choosing the right Overhead Projector for your particular application can be difficult and confusing if you don't have any experience or background with this type of equipment. The Overhead projector certainly is not a complicated piece of Audio Visual Equipment to use, but purchasing the Overhead Projector that fits your needs is an important decision.

The first thing that you need to consider is if your Overhead Projector will need to be portable or stationary. If your presentations require you to travel from location to location then you should certainly consider having a projector that offers you the portability of a briefcase type Overhead Projector. These projectors easily fold into the size of a large briefcase making them easy to transport, even through an airport. If you will be making your presentations say from a Boardroom or a Classroom where your Overhead Projector will spend most of its life then in most cases a portable Overhead Projector will not be necessary.

Once you have determined which type of Overhead Projector best fits your needs, then it's time to consider these options: Lamp changer, Open or Closed Head, Hi/Lo Switch, Lumen Output (How bright the projector is), Singlet, Doublet or Triplet Head, Standard Focal Length or Wide Angle. There is allot to consider when making your purchase and if you are not familiar with these terms it's easy for a fast talking salesman to sell you something you don't need or in some cases sell you something that isn't right for your particular application. I will briefly touch on each of these features to give you an understanding of what these terms mean and why or why not you need these options.

Also keep in mind that just like purchasing an automobile or a computer the more options you add to your Overhead Projector the more expensive the purchase price becomes. So consider these options and how they will fit into your particular application carefully before making your final decision.

Lumen Output: Lumens refer to the amount of light (brightness) that is produced by the projection lamp and the optics of the projector. Is your application going to be in a darkened room, partial light or full light? Generally speaking for Classroom or Boardroom use a projector that produces 3000-4000 lumens will be sufficient.

Lamp Changer: A lamp changer or dual lamp Overhead Projector is a projector that has two lamps and two lamp sockets. You are not burning both lamps at the same time; the idea behind this option is to give you, the end user, the capability of quickly changing to a new projection lamp during a presentation. This is often done by simply pushing a lever or flipping a switch. If changing a burned out projection lamp quickly during a presentation is critical then I would consider this option.

Hi/Lo Switch: The Hi/Lo switch controls the light output (lumens) of your Overhead Projector. Personally speaking I think that this option is more of a gimmick than a useful option. The claim is that when you don't need the high light output of your projector you can switch it to the low position saving lamp life. It's been my experience that this option rarely gets used, and does very little to save lamp life.

Singlet, Doublet, Triplet Head Assembly: These options also fall under the same category as wide angle projectors. In my opinion what should determine the necessity of these expensive options is the distance you will be projecting your image from. If you projecting from a short distance then you should consider purchasing a wide angle projector with at least a doublet head assembly. This will allow you to throw a large image on a screen or wall from a very short distance without losing the quality of your projected image. If you are using your Overhead Projector in classroom type environment then a Singlet Head Assembly will fit your needs.

Open or Closed Head: Now this is even a difficult decision for me. From a technicians stand point an Open Head makes cleaning the optics in the head easy. It also makes it much easier for the optics to be scratched or tampered with. A closed head offers the protection of these sensitive lenses, but makes cleaning them more difficult. We certainly see more damage to the Open Head Projectors in our shop than we do Closed Head.

Take the time to consider all of these options before you make your purchase and you'll be sure to purchase the Overhead Projector that fits your particular needs. One more thing I would like to mention is the offer of a "Lifetime Warranty". To quote one of the manufacturers that we purchase replacement parts from, "Lifetime Warranty, it's a huge gimmick to get people to purchase our product. In most cases they will never bother to use the warranty, and for those who do, they will find that it is a limited "Lifetime Warranty" and it covers only a few of the components in the projector." Don't let this gimmick fool you, purchase by reputation, there is no manufacturer that offers anything for nothing no matter how good the claim or warranty.

Mark Boehm is the President of M-B Electronics. He has over 25 years of experience in the Audio Visual and Electronics Industry. You can contact M-B Electronics at 800-872-9456 or by E-mail at etbinc@comcast.net

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