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Lunt Double Stack Filter for Dedicated Telescopes

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Higher Contrast For Dedicated Lunt Solar Telescopes

A dedicated Lunt hydrogen alpha telescope already reaches 0.7 Angstrom or better in single stack. Adding a double stack filter places a second etalon in series and pulls the combined bandwidth to 0.5 Angstrom or better. Lunt publishes tighter figures still on the current 40mm and 152mm systems. The Sun's surface gains contrast immediately.

Three versions cover the dedicated range. The LS40FHaP is a 40mm front mounted tilt tuned etalon for the LS40THa, and Lunt lists the pair at under 0.29 Angstrom combined. The LS50CP is a compact 50mm filter that threads onto the front of an LS50THa in seconds. The DSII/LS152T is an internal module for the LS152THa.

Expect filaments to break into dark cores and multiple strands, prominences to show internal threading from base to tip, and plage to separate cleanly from the background chromosphere. A Lunt blocking filter is required at all times, since the double stack filter is not a standalone safety device. Installation needs no tools and no factory return.

Lunt LS40FHa 40mm front mount double stack solar filter shown on a dedicated Lunt 40mm hydrogen alpha telescope

Key Features

  • Tighter Bandwidth - drops the combined system to 0.5 Angstrom or better, with Lunt publishing under 0.29 Angstrom on the 40mm pairing.
  • Model Matched Fit - comes in a version for each dedicated telescope, so the filter mates directly to the LS40THa, LS50THa or LS152THa.
  • Tilt Tuned Etalons - uses tilt tuned front mounted etalons on the 40mm and 50mm versions and a pressure tuned internal module on the 152mm.
  • Grab And Go Friendly - keeps the compact 50mm system light enough to stay on a photo tripod or a small Vixen compatible mount.
  • Tool Free Installation - threads or clamps into place without a factory visit, so the upgrade can wait until you want it.
  • Case Included - stores in an aluminium hard case with fitted foam on the front mounted versions.
Lunt LS50C compact double stack filter threaded onto the front of an LS50THa solar telescope
Specifications
Model / SKU LS40FHaP, LS50CP, DSII/LS152T
Type double stack hydrogen alpha etalon filter for dedicated Lunt solar telescopes
LS40FHaP 40mm front mounted 40mm tilt tuned etalon, fits the LS40THa series
LS50CP 50mm Compact compact front mounted 50mm tilt tuned etalon, threads onto the LS50THa front cell
DSII/LS152T Internal internal double stack module, fits the LS152THa
Clear Aperture 40mm or 50mm on the front mounted versions, no central obstruction
Bandwidth 0.5 Angstrom or better combined, with Lunt publishing under 0.29 Angstrom on the LS40THa pairing, about 0.35 Angstrom on current LS50THa telescopes and under 0.28 Angstrom on the LS152 module, and Lunt's own listing for the DSII/LS152T module quoting below 0.5 Angstrom pressure tuned
Single Etalon Bandpass 0.45 Angstrom on the LS40FHa, 0.4 Angstrom on the LS50C and on the LS152 internal module
Tuning tilt tuned on the 40mm and 50mm versions, Doppler True pressure tuning on the internal 152mm module
Blocking Filter required at all times and sold separately, with B500 or B600 suggested for the 40mm and B600 for the 50mm
Mounting threads or clamps onto the telescope front cell, or installs inside the optical path on the 152mm module
Installation customer installed, no tools and no factory return required
Weight LS40FHa 2 lb shipping, LS50C 3 lb shipping, LS152 internal module 7 lb shipping
Dimensions DSII/LS152T internal module 16 x 16 x 12 in shipping, not published for the front mounted versions
What's Included etalon filter assembly and aluminium hard case with fitted foam on the front mounted versions
Warranty 5 years from date of purchase against manufacturing and workmanship defects

Talk to a Specialist Contact Us Email a Specialist Shipping Info

Description

Higher Contrast For Dedicated Lunt Solar Telescopes

A dedicated Lunt hydrogen alpha telescope already reaches 0.7 Angstrom or better in single stack. Adding a double stack filter places a second etalon in series and pulls the combined bandwidth to 0.5 Angstrom or better. Lunt publishes tighter figures still on the current 40mm and 152mm systems. The Sun's surface gains contrast immediately.

Three versions cover the dedicated range. The LS40FHaP is a 40mm front mounted tilt tuned etalon for the LS40THa, and Lunt lists the pair at under 0.29 Angstrom combined. The LS50CP is a compact 50mm filter that threads onto the front of an LS50THa in seconds. The DSII/LS152T is an internal module for the LS152THa.

Expect filaments to break into dark cores and multiple strands, prominences to show internal threading from base to tip, and plage to separate cleanly from the background chromosphere. A Lunt blocking filter is required at all times, since the double stack filter is not a standalone safety device. Installation needs no tools and no factory return.

Lunt LS40FHa 40mm front mount double stack solar filter shown on a dedicated Lunt 40mm hydrogen alpha telescope

Key Features

  • Tighter Bandwidth - drops the combined system to 0.5 Angstrom or better, with Lunt publishing under 0.29 Angstrom on the 40mm pairing.
  • Model Matched Fit - comes in a version for each dedicated telescope, so the filter mates directly to the LS40THa, LS50THa or LS152THa.
  • Tilt Tuned Etalons - uses tilt tuned front mounted etalons on the 40mm and 50mm versions and a pressure tuned internal module on the 152mm.
  • Grab And Go Friendly - keeps the compact 50mm system light enough to stay on a photo tripod or a small Vixen compatible mount.
  • Tool Free Installation - threads or clamps into place without a factory visit, so the upgrade can wait until you want it.
  • Case Included - stores in an aluminium hard case with fitted foam on the front mounted versions.
Lunt LS50C compact double stack filter threaded onto the front of an LS50THa solar telescope
Specifications
Model / SKU LS40FHaP, LS50CP, DSII/LS152T
Type double stack hydrogen alpha etalon filter for dedicated Lunt solar telescopes
LS40FHaP 40mm front mounted 40mm tilt tuned etalon, fits the LS40THa series
LS50CP 50mm Compact compact front mounted 50mm tilt tuned etalon, threads onto the LS50THa front cell
DSII/LS152T Internal internal double stack module, fits the LS152THa
Clear Aperture 40mm or 50mm on the front mounted versions, no central obstruction
Bandwidth 0.5 Angstrom or better combined, with Lunt publishing under 0.29 Angstrom on the LS40THa pairing, about 0.35 Angstrom on current LS50THa telescopes and under 0.28 Angstrom on the LS152 module, and Lunt's own listing for the DSII/LS152T module quoting below 0.5 Angstrom pressure tuned
Single Etalon Bandpass 0.45 Angstrom on the LS40FHa, 0.4 Angstrom on the LS50C and on the LS152 internal module
Tuning tilt tuned on the 40mm and 50mm versions, Doppler True pressure tuning on the internal 152mm module
Blocking Filter required at all times and sold separately, with B500 or B600 suggested for the 40mm and B600 for the 50mm
Mounting threads or clamps onto the telescope front cell, or installs inside the optical path on the 152mm module
Installation customer installed, no tools and no factory return required
Weight LS40FHa 2 lb shipping, LS50C 3 lb shipping, LS152 internal module 7 lb shipping
Dimensions DSII/LS152T internal module 16 x 16 x 12 in shipping, not published for the front mounted versions
What's Included etalon filter assembly and aluminium hard case with fitted foam on the front mounted versions
Warranty 5 years from date of purchase against manufacturing and workmanship defects

Talk to a Specialist Contact Us Email a Specialist Shipping Info

Why Buy From Us

We get it. You've got a lot of choice when it comes to online retailers. Here's why we think you should shop with us at Telescope Depot.

But first, you should definitely hear from our customers here.

  • Available Free Shipping USA-wide.

  • Price Match Guarantee. Best prices online guaranteed.

  • 30 Day Easy Returns. No happy with your product, we'll take it back no questions asked.

  • Great Service. We pride ourselves on the best service, anywhere.

  • Your Satisfaction Guaranteed. We handpick our products for quality, we know you'll love them. But is there is ever something wrong, we'll fix it.

Shipping

This policy applies to orders from the United States. It is intended to ensure that you are aware of our shipping policies and procedures. By placing an order in this store, you accept the policies contained herein.

A.  Shipping Country

We currently ship to addresses within the United States.

At this time, we do not offer international shipping.

B. Order Processing Time

Orders are typically processed within 1–2 business days (Monday through Friday). Any orders submitted after our daily cut-off time, on weekends, or during U.S. public holidays will be processed on the next business day.

C. Order Cut-Off Time

Our daily order cut-off time is 5:00 PM ET

Orders received after this time will enter processing on the following business day.

D. Shipping Options

We offer the following shipping options:

  • Standard Shipping: 5–10 business days — Free
  • Express Shipping: 3–5 business days — $15

E. Carrier Services

For deliveries within the United States, we partner with reliable carriers such as USPS, UPS, FedEx, and DHL.

F. Tracking Information

Once your order has shipped, you will receive a shipping confirmation email containing your tracking number.

Tracking updates may take 24–48 hours to appear after dispatch.

If you have not received tracking information within 3 business days after your order has shipped, please contact us at sales@telescopedepot.com.

G. Address Change 

The delivery address cannot be changed after shipping. If you need to change the delivery location of your order, please contact us within 24 hours of placing your order at sales@telescopedepot.com.

H. Cancellations

If you need to change your order before receiving it, we can accept cancellations at any time up until shipment. If an order has already been shipped, please refer to our refund policy.

I. Damaged or Missing Deliveries

If your order arrives damaged, or if you believe there is an issue with your delivery, please contact our customer support team as soon as possible.

When contacting us, please include:

  • Your order number
  • A description of the issue
  • Photographs of the product and packaging (where applicable)

We will review the information provided and advise you on the next steps.

J. Contact Us

If you have any questions about shipping, delivery, tracking, or your order, please contact us:

Trade name: Telescope Depot

Phone number: +1 (855) 501-0541

Email: sales@telescopedepot.com

Address: 4941 Fountain Springs Dr, Gainesville, GA 30506, United States

Business hours: Monday–Friday, 9:00 AM–5:00 PM ET

What's Included
Reviews
Description

Higher Contrast For Dedicated Lunt Solar Telescopes

A dedicated Lunt hydrogen alpha telescope already reaches 0.7 Angstrom or better in single stack. Adding a double stack filter places a second etalon in series and pulls the combined bandwidth to 0.5 Angstrom or better. Lunt publishes tighter figures still on the current 40mm and 152mm systems. The Sun's surface gains contrast immediately.

Three versions cover the dedicated range. The LS40FHaP is a 40mm front mounted tilt tuned etalon for the LS40THa, and Lunt lists the pair at under 0.29 Angstrom combined. The LS50CP is a compact 50mm filter that threads onto the front of an LS50THa in seconds. The DSII/LS152T is an internal module for the LS152THa.

Expect filaments to break into dark cores and multiple strands, prominences to show internal threading from base to tip, and plage to separate cleanly from the background chromosphere. A Lunt blocking filter is required at all times, since the double stack filter is not a standalone safety device. Installation needs no tools and no factory return.

Lunt LS40FHa 40mm front mount double stack solar filter shown on a dedicated Lunt 40mm hydrogen alpha telescope

Key Features

  • Tighter Bandwidth - drops the combined system to 0.5 Angstrom or better, with Lunt publishing under 0.29 Angstrom on the 40mm pairing.
  • Model Matched Fit - comes in a version for each dedicated telescope, so the filter mates directly to the LS40THa, LS50THa or LS152THa.
  • Tilt Tuned Etalons - uses tilt tuned front mounted etalons on the 40mm and 50mm versions and a pressure tuned internal module on the 152mm.
  • Grab And Go Friendly - keeps the compact 50mm system light enough to stay on a photo tripod or a small Vixen compatible mount.
  • Tool Free Installation - threads or clamps into place without a factory visit, so the upgrade can wait until you want it.
  • Case Included - stores in an aluminium hard case with fitted foam on the front mounted versions.
Lunt LS50C compact double stack filter threaded onto the front of an LS50THa solar telescope
Specifications
Model / SKU LS40FHaP, LS50CP, DSII/LS152T
Type double stack hydrogen alpha etalon filter for dedicated Lunt solar telescopes
LS40FHaP 40mm front mounted 40mm tilt tuned etalon, fits the LS40THa series
LS50CP 50mm Compact compact front mounted 50mm tilt tuned etalon, threads onto the LS50THa front cell
DSII/LS152T Internal internal double stack module, fits the LS152THa
Clear Aperture 40mm or 50mm on the front mounted versions, no central obstruction
Bandwidth 0.5 Angstrom or better combined, with Lunt publishing under 0.29 Angstrom on the LS40THa pairing, about 0.35 Angstrom on current LS50THa telescopes and under 0.28 Angstrom on the LS152 module, and Lunt's own listing for the DSII/LS152T module quoting below 0.5 Angstrom pressure tuned
Single Etalon Bandpass 0.45 Angstrom on the LS40FHa, 0.4 Angstrom on the LS50C and on the LS152 internal module
Tuning tilt tuned on the 40mm and 50mm versions, Doppler True pressure tuning on the internal 152mm module
Blocking Filter required at all times and sold separately, with B500 or B600 suggested for the 40mm and B600 for the 50mm
Mounting threads or clamps onto the telescope front cell, or installs inside the optical path on the 152mm module
Installation customer installed, no tools and no factory return required
Weight LS40FHa 2 lb shipping, LS50C 3 lb shipping, LS152 internal module 7 lb shipping
Dimensions DSII/LS152T internal module 16 x 16 x 12 in shipping, not published for the front mounted versions
What's Included etalon filter assembly and aluminium hard case with fitted foam on the front mounted versions
Warranty 5 years from date of purchase against manufacturing and workmanship defects

Talk to a Specialist Contact Us Email a Specialist Shipping Info

Why Buy From Us

We get it. You've got a lot of choice when it comes to online retailers. Here's why we think you should shop with us at Telescope Depot.

But first, you should definitely hear from our customers here.

  • Available Free Shipping USA-wide.

  • Price Match Guarantee. Best prices online guaranteed.

  • 30 Day Easy Returns. No happy with your product, we'll take it back no questions asked.

  • Great Service. We pride ourselves on the best service, anywhere.

  • Your Satisfaction Guaranteed. We handpick our products for quality, we know you'll love them. But is there is ever something wrong, we'll fix it.

Shipping

This policy applies to orders from the United States. It is intended to ensure that you are aware of our shipping policies and procedures. By placing an order in this store, you accept the policies contained herein.

A.  Shipping Country

We currently ship to addresses within the United States.

At this time, we do not offer international shipping.

B. Order Processing Time

Orders are typically processed within 1–2 business days (Monday through Friday). Any orders submitted after our daily cut-off time, on weekends, or during U.S. public holidays will be processed on the next business day.

C. Order Cut-Off Time

Our daily order cut-off time is 5:00 PM ET

Orders received after this time will enter processing on the following business day.

D. Shipping Options

We offer the following shipping options:

  • Standard Shipping: 5–10 business days — Free
  • Express Shipping: 3–5 business days — $15

E. Carrier Services

For deliveries within the United States, we partner with reliable carriers such as USPS, UPS, FedEx, and DHL.

F. Tracking Information

Once your order has shipped, you will receive a shipping confirmation email containing your tracking number.

Tracking updates may take 24–48 hours to appear after dispatch.

If you have not received tracking information within 3 business days after your order has shipped, please contact us at sales@telescopedepot.com.

G. Address Change 

The delivery address cannot be changed after shipping. If you need to change the delivery location of your order, please contact us within 24 hours of placing your order at sales@telescopedepot.com.

H. Cancellations

If you need to change your order before receiving it, we can accept cancellations at any time up until shipment. If an order has already been shipped, please refer to our refund policy.

I. Damaged or Missing Deliveries

If your order arrives damaged, or if you believe there is an issue with your delivery, please contact our customer support team as soon as possible.

When contacting us, please include:

  • Your order number
  • A description of the issue
  • Photographs of the product and packaging (where applicable)

We will review the information provided and advise you on the next steps.

J. Contact Us

If you have any questions about shipping, delivery, tracking, or your order, please contact us:

Trade name: Telescope Depot

Phone number: +1 (855) 501-0541

Email: sales@telescopedepot.com

Address: 4941 Fountain Springs Dr, Gainesville, GA 30506, United States

Business hours: Monday–Friday, 9:00 AM–5:00 PM ET

What's Included
Reviews