Black isolation mask photographed separately

Isolation Mask for the Tri-Bahtinov System

Meade ETX-90 Mak / Black

$9.99

Product detail1 component

Isolation maskPhoto

Black component photographs shown. Shape varies by telescope model.

Isolation mask, image 1 of 1.

Isolation Mask for the Tri-Bahtinov System

One pattern at a time

Isolation Mask for the Tri-Bahtinov System

Make a closer alignment check with your tri-Bahtinov mask. The isolation mask covers two sectors so you can inspect one diffraction pattern at a time.

$9.99

Choose your telescope first to unlock color choices. Price varies by model.

Telescope Model

Color

See all four colors in the renders below ↓

U.S. standard shipping: $8 under $70; free at $70 or more. Delivery details.

Ask a question about your setup →

Model, fit, or choosing parts — we can help before you order.

One pattern at a time

Made for your next clear night.

Includes one isolation mask. A StargazeWorks tri-Bahtinov mask is required and sold separately or in a kit. Shield and dust cap are not included.

01

Isolation mask

Used with the tri-Bahtinov mask to cover two sectors and examine one pattern at a time.

Build your setup

See where the isolation mask fits in a focus-and-alignment setup. Read the telescope accessory guide, compare dew shields, or browse matched accessory kits. Choose the same telescope model for every matching part.

Designed to work together

One system. With or without the shield.

The masks and dust cap fit both your telescope directly and the matching StargazeWorks dew shield. Choose pieces for the same telescope model and use the setup that suits your session.

01

Start with the tri-Bahtinov

Fit your matching tri-Bahtinov mask directly on the telescope or in the shield.

02

Isolate a pattern

Place the isolation mask over the tri-Bahtinov and rotate it to examine each sector in turn.

03

Finish your check

Follow your telescope's instructions for adjustments. Remove both masks before observing or imaging.

Black — CAD product/assembly illustration — Illustrative CAD views show one model example. Geometry varies by telescope. Rendered colors are approximate; choose your order color above.

Brick Red — CAD product/assembly illustration — Illustrative CAD views show one model example. Geometry varies by telescope. Rendered colors are approximate; choose your order color above.

Real parts, in use

See the system on a telescope.

Original photographs show a Celestron SCT example. Check the captions for the parts shown.

Tri-Bahtinov and isolation masks fitted directly to a real Celestron SCT. Telescope is not included. The tri-Bahtinov mask is sold separately.

Made for your model

Made for your telescope.

Select the full model name in the menu above, then choose your color. Similar apertures can have different fittings.

Apertura AD8 Dob
Celestron 130EQ / 130SLT
Celestron 4SE Mak
Celestron 6in Dob
Celestron 8in Newt
Celestron C11 SCT / CPC 1100 / AVX 11 SCT
Celestron C5 SCT / 5SE SCT
Celestron C6 SCT / 6SE SCT / Evo 6 SCT
Celestron C8 SCT / 8SE SCT / Evo 8 SCT / CPC 800 / EdgeHD 8 / AVX 8 SCT / CGX 800
Celestron C9.25 SCT / EdgeHD 925 / CPC 925 / Evo 9.25
Meade ETX-105 Mak
Meade ETX-125 Mak
Meade ETX-90 Mak
Meade LX200 10in ACF
Meade LX200 8in SCT
Meade LX90 10in ACF
Meade LX90 8in SCT
Orion XT10 10in Dob / Apertura AD10 Dob / Zhumell Z10 Dob
Orion XT8 8in Dob
Sky-Watcher 127 Mak
Sky-Watcher 130P
Sky-Watcher 150 Mak
Sky-Watcher 150P / 150PDS
Sky-Watcher 200P Dob
Sky-Watcher 250P Dob
Sky-Watcher Flx 200P
StarSense 10in Dob
SW Quattro 150P
Zhumell Z8 Dob

Sky-Watcher Explorer 150P / 150PDS and Quattro 150P use different fittings. Pick the one you own. Need help finding your model?

Before your first night out

A few useful details.

Printed to order in carbon-fiber-reinforced PETG (CF-PETG), with a matte finish and fine print layer lines.

Ask us about your telescope

Can I use the isolation mask by itself?

It is designed to work with a StargazeWorks tri-Bahtinov mask. It covers two sectors of that mask to show one pattern at a time; it is not a separate focusing mask.

Can I use the pair without a shield?

Yes. The tri-Bahtinov and isolation pair works directly on the telescope or with the matching StargazeWorks shield fitted. Choose both masks for the same telescope model.

Which telescope model should I choose?

Choose the full telescope model name, then your color. Similar apertures can have different fittings. Sky-Watcher Explorer 150P / 150PDS and Quattro 150P use different parts; select the one you own. Contact us if your model is unclear or not listed.

What if the fit is not right?

If a part does not fit the telescope model on your order, contact us within 30 days of delivery. Confirmed fit or manufacturing issues receive a replacement at no charge. The guarantee does not cover selecting the wrong telescope model.

When will it arrive?

Normally dispatches in 1–3 business days. U.S. standard shipping is $8, or free on orders of $70 or more, with an estimated 3–5 business days in transit after dispatch. Express shipping is $15, with an estimated 1–2 business days in transit. Delivery estimates are shown at checkout.

Can you help me choose or use the system?

Tell us your model, which StargazeWorks parts you already have, and what you want to do. We can help you choose the right pieces or check how your setup works together. Use the question form on this page or contact us before ordering.

Let’s get your setup right

Ask us anything.

Tell us your model, which StargazeWorks parts you already have, and what you want to do. We can help you choose the right pieces or check how your setup works together. Send your question here. We’ll reply by email.