Projector/Gobo Help

WHICH PROJECTOR?

Choosing Your Projector

What do you Need to Consider?

The Projector Location

Mounting Point

The Ambient Light (LUX) levels

Choosing Your Projector

Choosing a gobo projector can be a little daunting as there are many products on the market with features you may not necessarily need. There is never a "one size fits all" solution, so knowing what’s right for your installation is key. This is a simple guide to give you the basics to decide which model is right for you. If you still need more help or have very specific requirements for your projection or project, contact us HERE and we will get straight back to you.

The Basics

”Gobo” stands for Goes Before Optics. It is a compact stencilled disk used in lighting fixtures to produce a projected image on to any surface. The design could be anything, from a simple pattern, to a logo or message, a complex drawing or a photographic image.

Gobos can project:

• Logos, text or messages
• Abstract patterns
• Photographic images – both greyscale & colour

They cannot project:

• A video – This is called ‘data projection’
• A ‘digital’ file that has been sent from a laptop or other device.

Please remember that your gobo is only as good as the projector projecting its image. Evica gobo projectors are the best on the market when it comes to optics, power and reliability. Check out our range HERE.

What do you Need to Consider?

• The Location

This includes the environment, the elements the projector will be exposed to, projection distance and the surface you are projecting onto.

• The Ambient Light levels

How bright is the area you are projecting in? Are you indoors or outdoors? What time of day do you need the projection to be seen.

• The Projected Image

Here we are talking about the final image size as well as the design and the colours that will be used.

The Projector Location

If you are mounting the projector outdoors, exposed to the elements, in a wet area or somewhere like a factory floor you need a projector with a minimum rating of IP65. All the new Evica EP+ range are to this standard and can also be fitted with a protective cowl for extra protection.

Mounting Point

Where you mount your projector will dictate what type of mount or attachments you will need. Evica Gobo projectors all have a yoke/arm bracket with a13mm attachment hole that can rotate either side of the projector so it can be floor or ceiling mounted. Again we have many mounting options and adapters. Please contact us HERE for advice.

What distance are you projecting?

This is very important and combined with the image size you require you can choose from a range of lenses to get this right.  Also be aware, the further the throw of your projection the more power you will need to keep the projection visible. The brightness of an image on a surface is measured in LUX. We’ll talk more about this shortly.

What kind of surface are you projecting on?

Be sure to consider the colour and type of surface you are projecting on. This can cause problems if not considered.

Bright surfaces provide brighter projections. Dark surfaces absorb light so you will need a more powerful projector to compensate for this or make sure the image you are projecting only uses open white colour as this is the brightest your projection can be. Getting these factors right is a balancing act but we have charts for each projector that can help you with this; giving image sizes and brightness set against the different powered models and choice of lenses. If you need specific advice, contact us HERE.

The Ambient Light (LUX) levels

LUX and projection surfaces

If you are projecting at night time or in a very dark room you can use a relatively low powered projector as there is no other light to compete with.

In lit environments or daytime settings you are competing with the sun. This is where the power of your projector is key. The projector needs to over power the light which is already on a surface. The ambient light which comes from this surface is measured in LUX. This measurement is really useful to decide how much power you need.

How bright is the area (LUX) levels?

How much light there is on the surface you wish to project onto determines how bright your projection needs to be. This is measured in LUX. A light meter can measure this exactly but to give you an idea here is some typical LUX levels

Moonlit street wall 5 lux

Street lit environment at night 10 lux

Average lit living room. 25-50 Lux

Lit Pub wall/floor        100-150 Lux

Office wall with artificial light 150-300 Lux

Lit Supermarket 400-500 Lux

Operating theatre walls 1000 Lux

These figures are for artificially lit rooms without daylight factors. The sun is 100,000 lux so the amount of ambient sunlight on a surface can make a massive difference in which case a light meter would be required. As you can imagine there is no projector that can compete with direct sunlight!

HINT: IDEALLY YOU REQUIRE YOUR PROJECTION TO BE DOUBLE THE LUX VALUE OF THE SURFACE LIGHT YOU ARE PROJECTING ON

The finished projection size you are looking for:

The finished projection size is going to be determined by the distance you are projecting and the lens/beam angle you choose for your projector.

With any light, the tighter the beam angle, the more concentrated the beam of light is, hence the image will be brighter (but smaller). The wider the beam angle, the more surface area the light is spread out over so although it will be bigger, it will also be less bright and less sharp.

HINT: WHEN YOU DOUBLE THE SIZE OF THE PROJECTION ITS BRIGHTNESS DECREASES BY A QUARTER

All our products have specification sheets with charts that clearly show the LUX values at various distances/image sizes for each lens choice. You can download the charts for the EP+ range. They are also available on the product pages.

here---> Lumen/Lux Charts

So as an example

I want to project a beer brand logo on to a bar wall in the evenings.

The pub environment is approximately 100-150 LUX

My mounting distance is about 4 meters away.

So I look on the chart to see which model can project around 300 LUX (double the pub environment) at 4m and what lens would be required.

Well I see the EP40+ can project 396 LUX (more LUX than we need) at 4m distance using the WIDE lens and this would give an image 204cm (pretty big for a bar over 2m!) .

I see also that the EP20+ can project 246 LUX (borderline depending on exact measurement and environment) for a 142cm image using the MEDIUM lens or…461 LUX (nice and bright) for 98cm image using the NARROW lens.

DON’T FORGET THOUGH!

If you are projecting onto a darker surface or have a particularly dark design double everything again or more if necessary. And please keep in mind light perception is in the eye of the beholder. These tools are a good guide. If in doubt get a LIGHT METER!!

GUIDE TO GOBOS

What is a Gobo?

Gobo Types

Projecting Dark Colours

Projecting at an Angle

Front and Rear Projection

Gobo Size

Supplying Artwork

What is a Gobo?

”Gobo” stands for Goes Before Optics. It is a compact stencilled disk used in lighting fixtures to produce a projected image on to any surface. The design could be anything, from a simple pattern, to a logo or message, a complex drawing or a photographic image.

Gobos can project

• Logos, text or messages
• Abstract patterns
• Photographic images – both greyscale & colour

They cannot project

• Video – This is called ‘data projection’
• A ‘digital’ file that has been sent from a laptop or device.

Please remember that your gobo is only as good as the projector, projecting its image. Evica gobo projectors are the best on the market when it comes to optics, power and reliability. Check out our range HERE

Gobo Types

There are 4 types of Gobo and these can be bought as off the shelf design or a custom gobo made specifically to your artwork. Metal gobos are used for stencilled or patterned images. Glass gobos are used to create more complex and colourful designs as well as photographic designs.

The 4 types of gobo are

• Stainless Steel Gobos
• Black and white Glass Gobos (also known as blackline)
• Spot Colour Glass Gobos
• Full Colour Glass Gobos

Stainless Steel Gobos

Steel gobos are laser cut from stainless steel discs. They are cost effective but do have a small restriction on the amount of detail or resolution. They do not last quite as long as glass gobos due to the high temperature of gobo projectors.

As these gobos are effectively stencils, some designs will not be suitable. For instance a letter O would need a tab to hold the centre of the O. In which case other styles of gobo are more suitable. Many companies have a large catalogue of steel gobo designs, so if you need a generic design like a star pattern for xmas for example, these can be bought quickly.

Black and White Glass Gobos

The most popular gobos are black and white glass gobos. They are made using a high resolution process, so no restrictions like the tabbing needed to make metal gobos work. The detail can be fine too, even photographic when using a screen (similar to the printing process). The glass can withstand high temperatures making them suitable for all projector types including the higher powered outdoor types.

These are created using a precision laser that removes a layer of reflective material from one side of the glass gobo. This lets the light through creating your image. This type of image is sharper than metal gobos and avoids the slight glow around the edge of projected images

Spot Colour Gobos

These gobos allow you to project an open white design with one other spot colour (or more). These are great for logos as the extra colour/s is great for branding.

These are created similar to the black and white glass gobos by combining two or more layers. One for white and the others for each spot colour. Not all colours are available but you can choose from a specific range to find your nearest choice.

Full Colour Gobos

A full colour gobo is as suggested. It produces a spectacular and intricately detailed image or design. It can take advantage of the full colour spectrum, gradients and shades.

This is achieved by combining 4 layers of glass gobo printed in CMYK. These layers are carefully sandwiched together. They are the most expensive gobos and must be handled with care when inserting in to the projector but are stunning to view.

To seek advice on gobo Artwork or design before ordering please contact us here and we’ll call you straight back.

Projecting Dark Colours

White is the brightest and best colour you can project and there are some colours that don’t project well for example navy or dark purple.

If you do need such colours as they are an essential part of your design there are design tricks you can use to help. Lightening slightly or adding a white outline to hold the shapes.

We will always check your artwork and give you our expert advice and be aware that the colour of the surface you project onto can have an effect to due to the way surfaces absorb light.

Projecting at an Angle

Ideally your projector should project at angle of 90° for maximum clarity and zero distortion but this is not always possible.

Projected at an extreme angle the image can appear warped but also bear in mind the angle that the projection is viewed from makes a difference too.

In some cases corrective software when making your gobo can remedy this. If you are projecting at an extreme angle it is best you contact us to discuss to avoid any issues.

Front and Rear Projection

Glass gobos are non-reversible unlike metal gobos. If you plan to rear project onto a translucent surface you will need to make sure your design is reversed. Again please talk to us if you want more information on this.

Gobo Size

There are many gobo sizes available but the current range of Evica projectors only uses SIZE E which is 37.5mm

Supplying Artwork

Computers and graphic design programs are both highly sophisticated and incredibly easy to use. With clients using a diverse range of platforms and software, Rosco will try to accept almost any electronic file. Of course, many designer still work in paper and photographic medium and we will happily take these "hard copy" artwork formats as well. Below is a set of guidelines to assist you in preparing your design - in whatever - format for a successful transfer to a custom gobo. 

Electronic Designs

Postscript Formats

Adobe Illustrator (.ai)

For almost any style design except for photographic images, the preferred, ideal file format is a native Adobe Illustrator file. This kind of vector-based artwork creates the best gobo toolings.

EPS Files (.eps)

A close second to Illustrator files are files saved in eps format. This format can be created from many of the popular graphics programs available. EPS files maintain excellent image qualities and allow for moderate resizing without degrading the image quality.

PDF Documents (.pdf)

PDF files are usually created from good art files such as above but have been converted from the original file to pdf so that a dealer or customer can open it. If you have an art file you can't open due to format, always send us this file first. We are happy to then convert it for you to an easier format for you to see the art as well. This helps us to get the best art possible and to keep it from being down graded to lesser art quality.

Word Documents (.doc)

Word Documents generally are not great art files but can be used for text-only art. We ask that you please include the font name & or the actual fonts when sending over this type of file. A faxed copy of the actual artwork is also requested for Word Document text art.

Rasterized Formats

Adobe Photoshop (.psd, .eps)

Native Photoshop files provide tremendous versatility by allowing all the elements of a design to be edited by Rosco's graphic designers. This file format maintains text editing (v.5 and higher) and preserves layers. In addition, Photoshop is the ideal format for photographic designs or Hi-Definition Photogobos.

TIFF Files (.tif)

Digital cameras and many graphics programs provide means for saving images in TIFF format. These files are uncompressed and maintain a very high image quality. However, they are often extremely large, so much so that electronic transfers are difficult. Despite that, this file format produces excellent gobos. TIFF files work wonderfully if they are a Photoshop created, layered file and are unlocked. This is especially so for full photographic quality gobos.

JPG (.jpg), GIF (.gif)

These file types are commonly found in use on the World Wide Web. In general, they are less well suited as artwork for custom gobos. GIF files are 72dpi, and contain a limited color table. This means that altering the file in any way - resizing, adjusting contrast, color correcting - is virtually impossible to accomplish without significantly degrading the image. So unless the file provided needs no alteration at all (very uncommon), it is a poor format choice. JPG files are a compressed file type that helps to keep even very complex images relatively small. But this compression makes it difficult to alter the image without introducing artifacts which degrade the image quality. If you will be submitting jpg files, make sure to submit a file that is 2x the size of the finished gobo.

CAD Files (.dxf, .dwg)

CAD files should not be submitted at all. Despite claims by the software companies to the contrary, these file types almost never successfully convert into a usable file format.

Image Size and Resolution Guidelines

First, if you are working in Adobe Illustrator, this section is irrelevant to you. Resizing in Illustrator is accomplished with no loss of detail or quality.

Otherwise, you must decide at what the resolution and size to create your design. Your choice of gobo type will influence this decision. In general, you should create your design at full size, which is 100% of the size of the finished gobo, or larger.

Help With Artwork

If you need help with your artwork, Evica Direct can help you with this. There is an hourly fee. Your artwork must be submitted in the right format and resolution.  Again our design service can help you here if you have issues.