Gobosource: Gobo FAQs

GoboSource Product & Service FAQ

Image Projection

What is a "gobo?"

The term "gobo" is shorthand for "GOes Between Optics." A gobo is a small disc that controls the shape and color of light from a projector. In most installations, the gobo is placed within the lens assembly at the focal point of the light source. Film gobos were common in theatrics historically, however, they have been replaced with metal and glass discs in most projection systems. To achieve the best quality images from our projectors, GoboSource specializes in stock and custom borosilicate glass gobos. The durable nature of this material ensures long lifespans and facilitates the greatest detail, contrast and color accuracy in projected imagery.

Can you animate my projection?

While we do not sell video projectors for tradtional video and animation projection, we do sell gobo projectors that can cycle between images on a configurable timer. These models are denoted with a "C" (or "CER") suffix for "changer," such as the 150CER. Additionally, many projectors include a rotatating holder to spin the projected image.

Video projectors are not suited for persistent image projection; therefore, they have not been incorporated into our projection solution ecosystem. Our projectors are specialized for long service intervals, with ECO Spot light source lifespans lasting around 15 times as long as equivalently bright video projectors.

What is a gobo’s Outer Diameter (OD)?

Outer Diameter (OD) is the rim diameter of the gobo disc, usually measured in millimeters (mm). If you don't know the light fixture type, we need to know at least the Outer Diameter and Image Diameter of a compatible gobo. Even if you tell us the fixture type, it is always a good idea to state an existing gobo's dimensions as well so we can double check.

What is a gobo’s Image Diameter (ID)?

Image Diameter (ID) is the maximum diameter of an image on the gobo, usually measured in millimeters (mm). The Image Diameter must be smaller than the Outer Diameter. If a gobo is manufactured with an Image Diameter that is too large for a specific projector, some outer areas of the image may be cut off from the projection. If you don't know the light fixture type, we need to know at least the Outer Diameter and Image Diameter of a compatible gobo. Even if you tell us the fixture type, it is always a good idea to state an existing gobo's dimensions as well so we can double check.

What are standard gobo sizes?

Some fixtures use standardized gobo sizes such as A, B, D, E & M. These define both the Outer Diameter AND the Image Diameter of your gobo. For example, per definition, a 'B-Size' gobo has an Outer Diameter (OD) of 86mm and Image Diameter (ID) of 64mm, but these dimensions can vary. If you know that you need a standard gobo size, you can state this instead of the Outer Diameter and Image Diameter.

Which B-size glass gobo type should I choose?

B-size is the most common gobo size, most 3.5” ellipsoidals (or lekos) such as the ETC Source Four (not Source Four JR) or most Altman types use this size. Our B-size glass gobos are mounted in metal adapter rings. These bezels allow the use our glass gobos in common metal gobo holders and thus eliminate the need for glass gobo holders.

We offer two different standard sizes for B-size gobos. One with a smaller image diameter and one with a larger image diameter. Both have certain advantages and disadvantages:

	B-size with 48mm Image Diameter	B-size with 60mm Image Diameter
Dimensions	Outer diameter: 86mm (3 1/4”) Image diameter: 48mm (1 7/8”)	Outer diameter: 86mm (3 1/4”) Image diameter: 60mm (2 1/3”)
Advantage	Has a better focus uniformity than larger image diameter.	Projects the maximum possible image size.
Disadvantage	About 23% smaller projection size than larger image diameter.	Image may get fuzzy on the outer edges with most lights.
When to Choose	When best projection quality is desired.	When the maximum possible projection size is desired.

Do you make A-size glass gobos?

Yes, these have an outer diameter of 100mm (4") and an image diameter of either 48mm or 60mm. Please see "Which B-size glass gobo type should I choose?" for the difference between the two image sizes. For custom glass gobos, we recommend using the B-size types instead since A-size gobos may have to be trimmed down in certain fixtures while B-size gobos fit usually fit such fixtures.

Do you make metal gobos?

Yes, even though we recommend using glass gobos, metal gobos are a cost effective option for simple artwork; however, glass is supeior to metal gobos in durability and detail. Metal gobos are not recommended for 24/7 projection solutions, as they will warp when constantly exposed to heat. In addition, when text or fine details are to be projected, bridging and tabbing must be incorporated in the artwork to support negative space, such as the openings in the letters "B" & "P." This may lead to undesirable effects in artwork reproduction. Go to our Metal Gobo Page for product details.

How heat resistant are your glass gobos?

Every gobo/fixture combination is unique and it is not possible to specify exact numbers. Our borosilicate glass combined with highly reflective coating makes our gobos extremely heat resistant. We pride ourselves on making the most heat resistant gobos in the industry. For maximum heat resistance, always mount the gobo with the reflective side facing the light source. To maximize glass lifespans in traditional theatrical projectors, adjust the lamp for hot spots, especially after a bulb change; this is especially important for fixtures that use light bulbs that draw more than 575W.

How should I handle my glass gobo?

Handle the gobo carefully when unpacking and installing. Don't touch the gobo surface with your fingers as the oil from your skin may 'bake in' when exposed to the high temperature of the light source. You can remove fingerprints with a soft cloth. If necessary, damp the cloth with water or a dilute, gentle cleaning solution. When not in use, store the gobo in a dry place.

How do I mount my gobo inside the projector?

Follow the directions for your fixture. For maximum heat resistance, the reflective side needs to face the light source, while the colored or white coatings must face away. In most installs, the design will appear mirrored when viewed from the front of the gobo holder.

Do I need metal or glass gobo holders?

Our ECO Spot™ projectors come with integrated gobo holders. However, typical theatrical fixtures require an interchangeable gobo holder or gobo wheel; the most frequently used gobos in these fixtures are simple metal gobos. Glass gobos are thicker than metal gobos (our gobos are usually between 1.1mm to 2.7mm thick). Most fixtures take glass gobos, but you may want to double check. We can mount larger gobos (like B, and M-Size) in a metal bezel so you can use your metal gobo holder.

Can my image be rear projected?

For rear projection (projecting against the back side of a screen), the gobo artwork needs to be mirrored. This is especially important for text projection. For symmetrical graphics, it is not necessary to mirror a gobo because it looks the same in both ways. You can temporarily flip our gobos in case you need them mirrored, but it is preferable to have the reflective side facing the lamp to ensure a long lifespan.

What is the typical lifespan of an ECO Spot™ projector?

Per design specifications, the LEDs in our projectors lose 30% effective luminance after 35,000 hours, which is known as the L70 rating. This refers to the brightness being 70% of original specification, which is mostly sufficient unless the projection was dim to begin with. The actual lifespan of the LED depends on temperature and other environmental conditions. In ideal (sufficiently cool & dry) environments, the raw LED life is approximately 60,000 hours and the drivers have a mean time between failures (MTBF) of 160,000 hours.

Ordering Process

What do you need from me to quote a custom gobo?

We need to know the gobo type you are interested in, such as metal, black & white, grayscale or color. It also helps to know the projector type that you will be using.
See our Custom Gobo Page for an overview and pricing. If you are not sure, submit a quote here and we will give you a recommendation based on your artwork, as well as details on pricing. At this point, providing a .jpg or .gif file is just fine. However, a link to a web page where we can see your artwork (for example a company logo) will greatly assist our artwork team in sourcing vector artwork. For producing the gobo, we usually need better artwork as described in our Artwork Guidelines.

What if I don't know all the details to fill out the order form?

We rarely need all the information requested in the forms. Fill in what you know and we'll fill in the blanks or call you to follow up if needed.

Why do I need to share my fixture make and model?

Almost every light fixture type has its own distinctive characteristics and uses special gobo dimensions. We can ensure the best projection quality if we know the exact make and type of your light fixture. If you don't know the fixture type, we need to know the specific Outer Diameter and Image Diameter of a gobo that fits in your projector

What is the production time for my gobo?

Custom metal, black & white or grayscale glass gobos require only 2 business days of production time.
Stock metal gobos require an average of 3 business days for production.
Both stock and custom colored glass gobos require 5 business days of production time.

If proof production is requested, add 1-2 business days for review and approval.

We can rush your gobos Same Day if the order is placed before 12:00 pm PDST.
For important Same Day orders, place the order online and call us to go over the details; please go here for more information about the ordering process.

What is the "Deliver by date?"

Use this field to specify the date when you need the gobos delivered. Please see our shipping options and terms.

How much does "Rush Service" cost?

Rush cost widely change with the gobo type and production time. The easiest way to find out is selecting the gobo type from this page Custom Gobo Page and select the appropriate "Ready to Ship" option. Keep in mind that shipping cost are added during order check out. For example, if you need a gobo tomorrow, select the "Ready to Ship" option "Same Day" plus "Overnight Shipping" during check out.

What is "Keystone Correction?"

Keystone correction is the process of warping an artwork to offset distortion due to an angled projection surface. The further the path of light and surface are from perpendicular, the greater the distortion effect will be. The keystone correction process is only needed at projection angles greater than 30°: this equates to an angle of 60° or less between the direction of the projection and the slope of the projection surface. If you select "yes" to "Need Keystone correction" when ordering a custom gobo, our sales team will get in touch to share the next steps of the process, which involves the measurement of the projection distance and projector mounting height.

Keystone correction is not recommended for installations that will be regularly repositioned. Each keystone corrected gobo will only appear correct at the specific position and angle for which they were measured and warped.

How are copies (duplicates) of my gobo priced?

Enter the number of additional duplicates to the original gobo. Duplicates cost less expensive than the first gobo and the total cost is calculated automatically in your cart.

Multiple gobos of multiple different artworks count as originals.
Multiple gobos in different sizes count as originals.
Multiple gobos with different keystoning count as originals.
Reorders of artworks count as duplicates.

How can I rent a projector?

We do not offer rental projectors for events. If you are working with an event planner, ask them about projector availability. Alternatively, search with the keywords "lighting rentals" or "up lighting" in combination with your city or county to find a lighting equipment rental business near you.

Artwork & Design

How should I title and describe art assets I upload to your site?

If you plan to upload artwork to your order history page, please make sure each artwork source file has a distinct name or identifier. It also helps production if you can append the the specific production method you have selected for each artwork in the title, such as "grayscale" or "2-color." You may also include additional comments and instructions, if necessary.

How can I send you larger files?

If you use our standard online order system, you can upload files of up to 40MB in size. If the file is larger or you need to send us another file, we recommend using "send.firefox.com." It's a simple and safe way to send files, no need to set up an account and the file will automatically be removed after a certain time. If you intend to email artwork to artwork@gobosource.com, include your order number or company name in the subject line if you are corresponding from an email not associated with an existing account at gobosource.com.

How will my black & white artwork be projected?

Gobos are usually processed in "Dark Field," which means that the artwork is reversed so that black artwork projects as white light and the rest of the gobo is blackened out. For this modification, please select the "standard" option. If you wish to project black artwork as dark, then please select the "reversed" option. In either case, colors usually remain unchanged.

How will the colors in my artwork be reproduced?

We try to match the colors of your artwork with the colors of our Standard Color Palette as closely as possible.

Please notify us if you need us to exactly match your color: we may need to upgrade your custom gobo production method. By mixing colors, we are able to make virtually any color on a gobo. For each matched color, your custom gobo will need a blend of 2 standard colors; for example, a single custom color with a white outline will be a three color custom gobo, and two custom colors require a full color custom gobo. However, we cannot guarantee the exact match of your colors in the resulting projection due to variations in the fixtures and projection surface. If you have special requirements, please let us know all the details of your planned implementation so we can make adjustments to properly project your artwork.

Should artwork be modified for rotation?

We usually center artwork within the image diameter on a gobo. However, when an image and text are rotated, such as a company logo and slogan, it looks better to center the base line of the text instead of the center-point of the logo. Let us know if you intend to rotate the gobo so we can incorporate this design modification.

How can I block out artwork details from my gobo, such as a date?

Use automotive gasket silicone and paste a thick layer over the art that you wish to hide. Gasket silicone is heat resistant and works well in even in the hottest running projectors. Get the opaque dark red or black silicone to make sure no light bleeds through. It's available in small tubes for less than $5 in most auto supply stores.