Astrophotography

Flat Frame Kits for
Serious Imagers.

EL Panel-based flat frame calibration kits — even, flicker-free illumination with zero hotspots across the full aperture. Used by astrophotographers worldwide to eliminate vignetting, dust shadows, and sensor artifacts before stacking. Sized from 5″ to 15″ diameter. Plug and play, no tools required.

Shop Flat Frame Kits Find Your Size →

5″–15″

Sizes in stock

Zero

Hotspots

Zero

Flicker

Custom

Sizes available

Why flat frames matter

What a Flat Frame Does — and Why the Light Source Matters

Every imaging sensor has a unique optical signature — vignetting from the optical train, dust shadows from particles on the sensor or filters, and pixel sensitivity variations. A flat frame captures this signature by imaging a perfectly uniform light source through the same optical train as your target.

During processing, your stacking software divides your light frames by the master flat, mathematically removing the sensor's optical artifacts and giving you a cleaner, more uniform base image to work from.

The quality of your flat frame is only as good as the uniformity of your light source. A light pad with hotspots, or a tablet screen with brightness falloff toward the edges, introduces new artifacts rather than correcting existing ones. The light source needs to be as uniform as physically possible across the full aperture.

Why EL Panels work better than alternatives

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True surface uniformity

EL Panels produce light from the phosphor layer across the entire panel surface — not from a series of point sources diffused through a material. The result is genuinely even illumination, not approximated even illumination.

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Zero flicker at any exposure

EL technology operates at high frequency AC — no 60Hz flicker, no PWM dimming artifacts. Consistent output at any exposure length including sub-second flats.

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Field portable

Battery powered. Lightweight. Takes flat against the aperture in seconds. Scratch-resistant carrying sleeve keeps the acrylic clean between sessions.

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Dimmable

Most kits include a dimmable inverter — dial the brightness down to achieve correct histogram exposure for your specific sensor and gain setting without voltage dimming artifacts.

Find your size

Size Your Kit to Your Telescope Aperture

Choose a kit diameter slightly larger than your telescope's aperture so the panel fully covers the opening. Smaller than the aperture and you'll see the panel edge in your flat frame.

Non-standard aperture? We fabricate custom EL Panels cut to any diameter. If your telescope doesn't match a stock size — or you need a square or rectangular panel for a camera lens or filter drawer — contact us with the dimensions and we'll quote a custom cut.

What's in each kit

Everything You Need. Nothing You Don't.

Every kit ships plug and play — no soldering, no wiring. Customize the inverter and acrylic options to match your setup in the product dropdown.

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EL Panel Circle

The light source itself — circular EL Panel cut to the kit diameter. White phosphor with white overlay for neutral appearance when powered off. Even illumination across the full surface, pre-terminated and ready to connect.

Included in all kits

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Dimmable Inverter

Adjustable brightness inverter — dial down to the correct histogram exposure for your sensor without voltage-dimming artifacts. Power options include USB (5V), 9V battery pack, 12V rechargeable, or 12V AC adapter depending on kit size.

Select power option in dropdown

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Frosted Acrylic Disc

Laser-cut frosted acrylic in the same diameter as the EL Panel. Diffuses the light further, reduces phosphor granularity at high magnification, and softens the color temperature to a clean neutral white. Optional — but recommended for fast scopes and high-resolution sensors.

Optional — 1pc or 2pc sandwich

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Scratch-Resistant Sleeve

Protective carrying sleeve for the panel and acrylic — doubles as a cleaning cloth before taking flats. Keeps the acrylic surface clean in your gear bag between sessions. Included with 2022 and newer kits.

2022+ kits

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3D Printed Cap/Base

Optional 3D-printed plastic disc with a small lip that fits over the telescope aperture — holds the flat frame kit hands-free while you're taking frames. Tape the inverter to the back to keep the whole assembly together. Currently available for 5″ and 6″ kits.

Optional · 5″ & 6″ kits · Sold separately

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Extra Acrylic Disc

Replacement or additional frosted acrylic disc in case of breakage, loss, or if you want to sandwich the panel between two pieces for maximum field durability. Available individually to match any kit size.

Sold separately

Power options

Choose the Power Setup That Fits Your Rig

Kit size determines which inverter options are available. Smaller kits (5″–8″) run well on USB or 9V battery. Larger kits (10″–15″) need 12V.

5″ – 8″ kits

5V USB Inverter

Powers from any USB source — power bank, scope USB port, laptop. Lightest and most portable option. Push-button dimmer or touch dimmer versions available. Rechargeable battery option available for completely self-contained setup.

USB-C · Power bank compatible

5″ – 8″ kits

9V Battery Pack Combo

Self-contained 9V battery pack with built-in inverter — no external power source needed. Simple and field-ready. Good for imagers who want a fully standalone kit without cables.

9V battery · Self-contained

10″ – 15″ kits

Mondo 12V Inverter

Adjustable brightness wheel directly on the inverter — dial in exact histogram exposure. Powers from 12V rechargeable battery, AC adapter, or your scope's 12V output (2.1×5.5mm barrel). Most popular choice for larger apertures.

12V DC · Dimmable · Rechargeable or AC

From the field

Acrylic application

Start on one edge and press slowly with a flat tool (credit card or squeegee) to push air bubbles out as you go. Apply to the textured face of the acrylic for best adhesion. Air bubbles underneath the acrylic will show up as shadows in your flats.

Granularity & fast scopes

At high magnification or with a fast focal ratio scope, you may see EL phosphor granularity in your flats. Adding the frosted acrylic disc eliminates this by diffusing the panel surface. Recommended for anything faster than f/6 or with a full-frame sensor.

Histogram exposure

Aim for 30–50% histogram peak when taking flats — bright enough to capture the optical signature, not so bright it clips. Use the inverter dimmer first, then adjust exposure time if needed. Avoid voltage-dimming (using a weaker battery) as it can alter the EL spectrum slightly.

Non-standard aperture or custom application

Need a custom size?

We cut EL Panels to any diameter, square, or rectangular shape. Send us your aperture dimensions and we'll fabricate a panel to fit.

Shop All Kits Custom Size →