Hydrogen Alpha Filters

Click for In-stock items

Current Delivery Times

0-10 days for:
Original Quark
uestar Quark
Combo Quark
Calcium Quark

3-6 weeks for:
Blocker and Trimmers
ION Filters
CaII H line filters
Quantum upgrade:  
Quantum SE Filters

3-6 months for:
Quantum PE Filters
Ca II K Line PE Filters
Sodium Line FIlters
SR-127 Telescope
Solar System Filter Wheel

Limited Remaining Supply of
SolaREDi 66 Scopes

Energy Rejection Filters

Adapters & Snouts

Solar Introduction
Resolution and
Aperture Choices
Photo Gallery
Service / Repair
Upgrade or Trade-in
Filter Specifications
DayStar Dealers

Request Quotation

Recent Trade Shows
Terms of Sale

About Opening
a DayStar Filter

The Sun Today

Through the years, DayStar has repaired hundreds of filters where curious astronomers felt they might open the assembly to try to fix a problem themselves. The tragedies are too sad to list here. Don't let your filter be one of those casualties!


We understand that astronomers, by nature, are a curious and educated type of person. We regularly receive requests from customers and DayStar Filter owners about how to service the elements or inside of a DayStar Filter.  We sincerely hope that any owner or user of a DayStar will read this page about the filter to satisfy your curiosity and understand that opening your filter has no positive results, and only negative ramifications.  

  1. Opening the DayStar Filter exposes your filter to many types of unrecoverable damage, we therefore void any warranty should the filter assembly be opened. We can tell if a DayStar Filter assembly has been opened.
  2. A DayStar Filter is a multi-cavity filter stack assembly.  There are 7-12 optical elements housed between two anti-reflection coated windows, bonded by a specialty optical couplant.  No component is user-servicable. Should any element fail, it must be replaced in the DayStar Filters laboratory.
  3. The filter stack assembly is housed under slight tension to maintain equal and even pressure between the optical layers over a many year lifespan.  Often, when that pressure is released, air can enter the filter stack and/or visible creases form in the lubricated cavities created with that release of pressure.  The result can be air bubbles and/or spider veins in the assembly.  Usually, that result can only be restored by a full optical stack reassembly in the DayStar laboratory.
  4. DayStar Filters are coupled with a special purpose optical couplant not available to the public.  It is NOT grease. That couplant does have an oily consistancy. This special optical couplant must be rated for the temperature, longevity, viscosity and transparency ratings of a DayStar Filter's special needs and cannot be substituted.  It must be special ordered in bulk direct from the manufacturer and is extrememly expensive. (A jar of which is more expensive than the standard repair cost of blockers and trimmers)  A DAYSTAR FILTER CANNOT BE REASSEMBLED WITHOUT THIS OPTICAL COUPLANT. In other words... if you take it apart, you can't put it back together without the special ingredient.
  5. The Fabry- Perot Etalon is an excruciatingly fragile element.  Housed deep inside your filter, it must remain undisturbed or it could experience damage. Damage occurs when elements are separated, twisted, pulled or slid against one another; or even the release of tension in opening the filter assembly. That motion causes sections of the coating to slide, clump or vein in effects as light as crackling or severe as complete coating failure. The etalon is the most delicate, fragile and expensive part of the DayStar Filter.  Simply releasing tension from your housing puts your etalon at risk of permanent damage. A damaged etalon crystal will deliver off-band and/or uneven width or wavelength light throughout the image.  It is not possible to repair a damaged etalon crystal.  It must be replaced.
  6. Some optical elements within the filter must tune to each other.  It is not possible to discern this precise tuning without advanced spectroscopic testing equipment and a fundamental understanding of the filter assembly process and in-house standards. We regularly see filters which have been disassembled to be returned to us in non-working condition because the elements are reassembled out of tune.
  7. Undisturbed, a filter can last 30 years or more.  Without being opened, the optical couplant does not leave the cavity and does not age or need replaced. The likelihood that your filter requires disassembly due to "grease" is nil... unless it has been opened by an unauthorized person. The only elements which ever require service on an undisturbed DayStar Filter are the blocker and trimmer elements (which slowly deteriorate over 10-30 years depending on environmental conditions) ; or the heater housing. Blocker and trimmer elements must be produced in bulk and to our exclusive specifications.  Individuals do NOT have access to these blocker and trimmer elements and cannot replace them themselves.
  8. Once open, the filter elements are extremely fragile and subject to damage with exposure to unclean air. Unlike other optical elements in the optics industry, some components in the optical stack have thin film coatings and/or soft surfaces that cannot be wiped, touched or even blown on without damage occurring.  Optical assemblies of this type must be handled in a true optical clean-room environment by trained professionals who are specifically knowledgeable about these specific technologies.
  9. To the untrained eye, and without the laboratory and associated specifications, it is not possible to properly assemble its component elements. Should a filter be taken apart and re-assembled, an owner would not be able to troubleshoot its cause of nonsuccess. Due to the dozens of possible assembly and damage concerns, DayStar cannot diagnose these malfunctions without an exam of the filter in the laboratory.
  10. A DayStar Filter assembly does not offer any technology inside which can be backwards engineered. Our protected DayStar technologies are special to the means by which the filter and optical elements are constructed.  Simply examining the assembly order of the finished component elements offers no insight into the methods by which our manufacturing processes are done. This warning is not aimed at preventing curiosity and a quick learner from fixing something he or she might on his own in order to to protect our secret recipie.  It is because we care about the long, continued life of your filter. There are NO user serviceable parts or features inside the sealed compartment of a DayStar Filter assembly.  Our fees are reasonable and will assure the long health of your filter for many years to come.

Through the years, DayStar has repaired hundreds of filters where curious astronomers felt they might open the assembly to try to fix a problem themselves. The tragedies are too sad to list here.

Don't let your filter be one of those casualties!  Just DON'T open it.  

Send it back to: 
DayStar Filters LLC
149 Northwest OO Highway
Warrensburg, MO 64093

Problems seen: 
Typical Symptoms
Repair Cost:
Failed Blockers & trimmers
  • Dark splotches or
  • Edge darkening towards
    the inside of the filter
Failed heater
  • Housing doesn't feel as hot as it used to.
  • Image doesn't show prominences anymore.  (Offband)
Heater knob set
too high
  • Knob should be set at 6.0
  • Filter will be off-band at wrong setting
  • Heater circuit will blow if turned above 8
Free to $700
Filter is dirty
  • A sligthly dirty filter can be blown off with Dustoff or a photo dust bulb. Be careful not to allow any liquid propellant to hit the glass surface.
  • A very dirty filter must be sent back to DayStar for complete Clean and Check Service
Free to
"Optical 'grease'
has separated"
  • Once again, we don't use a grease.  The only way for optical couplant to separate is to open the filter.  
  • DO not open the filter.  
  • Send it back.
  • Most who think they have this problem actually have bad blockers and trimmers.
$150 - $750
Spider veins
  • Lines in image and/or visible lines on viewing filter.
  • This is caused by opening the filter. It may be minor or may be permanent damage to the filter.
$150 -
full replacement cost
Etalon damage
  • This is caused by opening the filter resulting in permanent damage to the filter.

DayStar Filters LLC 149 Northwest OO Highway   Warrensburg, MO 64093 - USA
866.680.6563service@daystarfilters.com • FAX: 1-866-791-0448

website by Jen Dudley